Spazio 2050 n. 5 - The weather of the Sun by Spazio 2050

Space missions and frontier studies to get to know our star and its space weather

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Magazine of the Italian Space Agency | July 2022

The weather of the Sun

1 0 1 0 0 1 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 0 0 1 1 1 0 1 0 0 1 1 0 1 0 0 1 0 1 0 0 0 1 0 1 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 0 1 1 1 0 1 0 0 1 1 1 0 0 1 0 1 0 0 0 0 1 1 1 0 1 0 0 1 1 0 0 0 1 0 1 0 0 1 0 0 1 0 1 0 0 1 0 0 1 0 0 1 0 1 0 1 0 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 1 0 0 1 1 1 0 1 0 0 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 0 1 1 1 0 1 0 0 1 0 1 1 1 0 1 0 0 1 1 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 1 0 0 1 0 0 1 0 0 1 0 1 0 1 0 0 1 0 0 1 1 1 0 1 0 1 0 0 1 1 1 0 1 0 0 1 0 0 1 0 1 0 1 0 0 1 0 0 1 1 1 0 1 0 0 1 1 0 0 1 1 1 0 1 0 0 1 1 1 0 0 1 0 1 0 0 0 0 1 1 1 0 1 0 0 1 0 1 0 0 1 0 1 0 0 1 0 0 1 0 0 1 0 1 0 0 1 0 0 1 0 0 1 0 1 0 1 0 1 0 0 1 1 0 1 0 11 00 01 0 0 1 0 0 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0 1 0 1 0 0 0 0 01 10 0 0 1 1 1 0 1 0 0 1 0 1 0 1 0 0 1 0 1 0 1 0 1 0 0 1 0 1 1 0 1 0 0 1 THE KNOWLEDGE [TO] PROTECT ACCELERATINGTECHNOLOGYEVOLUTION Security is our commitment leonardo.com Monitoring of strategic data and assets. Predictive and proactive protection from physical and cyber threats. Secure digitisation of processes. Critical communications. These are the technological and operational capabilities that Leonardo offers institutions, members of the public, infrastructures and businesses. 115,000 security events monitored per second, and 1,800 alarms handled every day by the Global SOC (Security Operation Centre). 75 cyber-protected NATO sites in 29 countries and critical communications systems operating in more than 50 countries. Leonardo strives daily to enhance and keep data safe and secure in a world increasingly dependent on it.

Cses-Limadou hunting for earthquakes from space by Manuela Proietti 30

Curated by ASI Multimedia Unit Head of Unit: Giuseppina Pulcrano

Space weather, under special surveillance by Mauro Messerotti

Light on the dark Universe with Euclid by the ASI’s editorial staf 32

Newspaper of the Italian Space Agency Insert of Global Science

ISSUE NUMBER 5, JULY 2022

Aspis, a new prototype of scientifc data centre, targeted at the study of space weather by Giuseppe Nucera

Solar Italy - infographic by Manuela Proietti

The Parker’s journey by Luca Mingotti Landriani

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Italy reaches the Sun with the Soho mission by Fulvia Croci 34 Spacearth Technology – Commercial solutions from Science by Silvia Ciccarelli

Identikit of the space weather by Mirko Piersanti

What’s the weather like… in the Solar System? by Barbara Ranghelli

Printed by Peristegraf srl Via Giacomo Peroni 130, Roma

Sun: it’s a matter of physics by Giuseppe Nucera

Editorial coordination Manuela Proietti, ASI Multimedia Unit

Thanks to ASI colleagues Barbara Negri, Cristhina Plainaki, Marco Stangalini and Simona Zofoli for scientifc advice.

Solar

In the cover medialab.Esa/AtgCreditisOrbiter.

Media outlet of the Globalist group Registration at the Court of Roma 11.2017 of 02.02.2017

See the word “Sun” by Valeria Guarneri

Open Innovation: the 2022 edition of the #T-TeC Telespazio kicks of by Marco Brancati

Eugene Newman Parker, the pioneer of heliophysics by Giuseppina Pulcrano

Design Paola Gaviraghi

The adventures of a star called Sun by Marco Cattaneo

Touching the Sun with the Solar Orbiter by Giulia Bonelli

Unraveling the dark side of the Sun by Paolo D'Angelo

Managing director Gianni Cipriani

SUMMARY

Living under another star by Amedeo Balbi

Among all those stars, there’s a special one, or at least one which is special for us. Because, as a matter of fact, the Sun doesn’t seem to have anything special, in hindsight. In fact, if we observe it with detachment, it’s an anonymous star from the main sequence, located on a peripheral arm of the galaxy’s disk, 28.000 light years away from its center. However, even if it’s just an ordinary star, it has its numbers. First of all, it contains 99.8% of the matter of the whole Solar System, its diameter is over 100 ti mes higher than the Earth and its superfcial temperature is about 5.500 degrees, which, however, become 15.000.000 degrees in its core, which is home to the fusion reactions which make it shine. And even if it burns as many as 5 million tons of hydrogen per second, it’s been there for at least 4 billion and a half years and will remain there for almost as many years, before running out of fuel and turning into a huge red star. While its core will shrink, the most external layers will be expelled until the orbit of Mars, will swallow anything they will fnd along their way, including the Earth, and will produce a planetary nebula. At the end of this spectacle, what will remain is a white dwarf, which will continue to shine, more and more weakly, with residual heat. But let time run its course, and let’s take

calledofadventuresTheastarSun

Istoria e dimostrazioni intorno alle macchie solari (History and demonstrations around sunspots) by Galileo Galilei, Rome, 1613. Florence, National Central Library.

If we look up to the sky, in a clear night without Moon, in a place spared by artifcial lights, we can count a few thousand stars. A handful, com pared to the endless landscape of celestial bodies around us. Thanks to increasingly powerful tools, we are classifying them with accuracy and stubbornness. We may get lost if we navigate the huge map of the Milky Way produced by the observations of the Gaia space mission and publi shed on June 13th by the European Space Agency. Almost two billions of stars which, if we look at them distractedly, have the aspect of more or less identical bright dots, scattered along the cosmos’ black carpet. And think that all those stars are a minimum part of all the celestial bodies which compose it, at least 100 billion.

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by Marco Cattaneo

inHerschel,Williamtheend of the XVIII century was pioneer of cartography.stellar

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millenniums our curiosity about what happens inside that freball hanging over us was fru strated by its blinding light, which prevents us from observing it with the naked eye, except at our risk and peril. And yet we tried, so much so that the ancient Chinese astronomers, at least in the II century BC, had already noted down the presence of spots, one for each decade according to their texts, on that shiny and apparently uniform surface. And even before, Theophrastus of Athens, a pupil of Aristotle, in its De Signis Tempestatum, had put them into relation with the meteorological weather, and had got to use them to formulate weather forecasts which, ça va sans dire, weren’t really accurate.

A pioneer of stellar cartography such as William Herschel already knew, at the end of the XVIII century, that we aren’t in a particularly privileged position in the cosmic spectacle. But the Sun is our star: it has formed a pla netary system that, up to a few decades ago, was the only one we knew and, with its bustling activity, has allowed the birth of life on this planet, and our bir th. We ask ourselves questions, after all the Sun is so close that, according to ancient people, it was located on an orbit a stone throw away from us, between Ve nus and Mars. And its daily being born and dying has been catching the attention of human beings since the dawn of

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It’s with the advent of the telescope that we were able to start observing the Sun more closely, although with even more risks. In 1610 Thomas Harriot, a British astronomer and mathematician, thought to observe the Sun at dawn, on a winter’s morning with thick fog –according to the typical British stereotype – when the light, a few degrees above the horizon, would cross a thicker layer. The method developed by Galileo in the same years was defnitely more ingenious. In fact, the scientist from Pisa studied the Sun without directly staring into its light. He would let the light come out of the ocular and project it on a piece of paper. By doing that, he didn’t just consistently observe the solar spots, but by following the motion of what he interpreted as fat clouds on the star’s surface, he realized that the Sun had to rotate on its axis and, based on their deforma tion, he inferred that it was a sphere. Galileo threw into crisis both the conception of the Sun as a perfect ce lestial body and the immutability of skies and in 1613, with his Istoria e dimostrazioni intorno alle macchie so lari e loro accidenti (History and demonstrations around sunspots and their accidents), he exacerbated his endless challenge to the Aristotelians’ theories. However, for quite a long time the Sun confned us to its

An image of the solar Credits:activity.Nasa/Sdo.

However,time.for

a step back.

The solar wind is also the protagonist of the second aspect that we’re investigating with the Parker probe, but also with the European Space Agency’s Solar Orbiter. «We must understand how the magnetic feld gi ves origin to wind», continues Velli, «what properties of wind are rela ted to the source on the Sun which emits it, and what are the main pro perties of the diferent types of solar wind. And by doing this, we must enter into the dynamics of solar fares, magnetic storms, coronal mass ejections (CMEs), which are essential phenomena for the space weather », that is space meteorology, the young science which studies the perturba tions of the interplanetary space and how it may end up infuencing the functioning of our technological systems, in space and on Earth. «And fnally, we’re trying to understand the solar cosmic rays, the origin of the swarms of energy particles emitted by the Sun and why some fares give

Credits: Nasa.

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of the satellite.ObservatorySolarOrbitingﬁrst

The frst Nasa’s Orbiting Solar Observatory during the assembly stage.

surface, where we gradually observed the violent expressions of the tur bulences which, with all likelihood, shook its internal part. Among them are the magnetic felds of solar spots, which were discovered by Ge orge Ellery Hale at Mount Wilson Observatory. But after Galileo, it took three centuries, or even something more, to understand what lets the Sun and the other stars blaze – let’s leave love apart, so as not to upset the great Dante -. In 1920, Arthur Eddington was the frst one to suggest that stars release their energy thanks to the fusion in their cores of hydro gen into helium and heavy elements are formed inside them. And almost twenty years later, in a memorable article published in Physical Review (“Energy production in Stars”), Hans Bethe analyzed the possible fusion re actions happening in stars, and concluded that there were two processes that could be regarded as the most plausible: the proton-proton chain reaction, which is predominant in small-sized stars, and the carbon-nitro gen-oxygen cycle, which is more relevant in the heaviest from the main sequence.

But the golden age of solar studies arrived with the space age, also because satellites can detect solar radiations and particles which do not reach ground level. And it’s precisely 60 years ago, with the launch of the frst Orbiting Solar Observatory satellite, that we started to measure the X-rays and gamma rays emitted by solar fares. From then on, the dynamics which regulate the activity of the Sun – including the dangers for our fragile civilization, related to its most violent expressions – have been clarifed in more and more detail, even if it still takes a lot of time to disclose all its secrets. «There are three specifc mechanisms that we are exploring with the current missions», explains Marco Velli, profes sor of Space Physics at the University of California, in Los Angeles, and principal investigator of the Parker Solar Probe, the NASA probe launched in 2018 with the task of observing the external solar corona. «The frst aspect is understanding why the solar corona exists and why it gives ori gin to wind». Because the heating of the solar corona, the most external part of the solar atmosphere, looks like a paradox. Whereas a temperatu re of a few degrees is recorded at the star’s surface, the corona can reach up to 2 million degrees. «Since the heat doesn’t spontaneously fow from a cold body to a warm body, there are some mechanisms with which the magnetic body transfers energy to the corona. And therefore, it’s exactly the magnetic feld which generates it and, at the same time, confnes it. By the way, the magnetic feld is the engine of the solar wind, the stream of particles which, from our star, permeate the interplanetary space, but then some dynamics are triggered between the magnetic feld itself and the wind, which we don’t understand much yet».

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Being able to predict, reasonably in advance, such extreme phenomena would at least allow to try and batten down the hatches. But that’s not all of it. The whims of solar activity cause a risk which we are unable to assess for a potential mission on Mars with a human crew aboard. «At the moment, a mission to Mars implies an 8-9 month journey in the interpla netary space. Should one of these solar storms hap

«What we are investigating on the Sun is frontier phy sics, which covers diferent subjects. The studies on the magnetic feld confnement of the plasma in the solar corona have drawn the attention of those who, on Earth, are trying to bridle the nuclear fusion to produce energy». And the knowledge of the mechani sms with which the magnetic feld interacts with the corona might give us some good tips to be able to f nally “bottle”, the fusion processes in a reactor for the production of energy.

made by the Gaia

According to Velli, one of the future priorities is the exploration of solar dynamics in three or four dimen sions. Because, so far, the Sun has allowed us to “tou ch” just its surface, a bit like it happened with oce ans until a few decades ago. Instead, we would need to study its phenomena even in depth. And not only that. We would need to have tools available which can follow the course of events at least for one or two so lar cycles, each one lasting 22 years. Only by doing so we can hope to unravel the mechanisms of our star. And, a bit like Prometheus did when he stole fre from the gods, to treasure its benevolence for our wellbeing and for the planet’s health. Because, in the end, we al ready owe everything to the Sun.

cations in diferent felds. «First of all, it may improve our knowledge in terms of space weather – specifes Velli – because we’re still very much behind when it comes to the ability to predict violent events. We’re unable to accurately predict fares or coronal mass ejections, unless we do it just a few hours earlier. And it still takes a very long time before being able to understand what could be their impact on Earth. The amount of energy released by a CME is equal to 10 million Tsar Bombas, the most powerful hydrogen bomb ever tested, a 50-megaton bomb. If this energy was collimated enough, towards our planet, the re sulting beam of particles may lead to relevant conse quences. By restricting the terrestrial magnetic feld, it would produce an electric feld in the atmosphere, capable of crashing power plants».

Credits: Esa/Gaia.

The material which makes up this celestial body and its magnetic felds is in constant motion and gives origin to a set of physical structures and phenomena, whose typical evolution time scale may vary from a few seconds to a few years, or even hundreds of thou sand years if we think of the phenomena which cause the variation of the solar activity on the long run. The variety of these characteristics and the phenomena related to them, as well as the peculiarities of the sin gle layers of the Sun, both the internal ones and those within its atmosphere, is such as to deserve a guide, a kind of “solar encyclopedia”.

by Valeria Guarneri

Later on, we have the radiative zone. It’s an area with variable density, which owes its name to the process with which energy is produced by nuclear fusion re actions. In this area of the stellar interior, the energy produced in the core is transferred towards the most external layers through the radiation.

The most external layer of the internal structure of the Sun, the convection zone, makes up about 2/3 of the volume of our star and is a lot less dense than the immediately more internal zone, the radiative one. Here, the main mechanism for the transport of energy is convection. This zone’s warm material goes up towards the Sun’s surface and brings heat with it; as soon as it cools down, emitting light, it sinks downwards, where it collects more heat. The con vective motions can be seen on the Sun’s surface in the form of plasma “bubbles”, the so-called granules or

Let’s begin with the most internal layers, starting from the core. It’s an actual engine, the “heart” of the Sun; it’s 10 times thicker than lead and its tempera ture is above 16 million degrees; here, the pressure of the surrounding layers is so high that hydrogen atoms are “squeezed” in helium, releasing light and energy during this process. This reaction, known as nuclear fusion, has been giving “charge” to the Sun for over 4 billion years.

GLOBALSCIENCE.IT A practical guide to the structure and signs”“particularofourstar

It is characterized by a layer confguration and a wide range of “exotic” and impetuous phenomena which infuence space also at a distance of billions of kilo meters; furthermore, its “efervescent” activity, which is partly yet to be investigated, is a constant object of study. We are talking about the Sun, the parent star of our planetary system, the protagonist of exploratory missions – such as the ESA Solar Orbiter and the NASA Parker – which are providing precious data to outline an increasingly accurate profle.

the solar atmosphere, with a thi ckness of over 400 kilometers and average tempera tures of over 5.000 °C: we’re talking about the photo sphere, which emits a white sheen, that can be visible with the naked eye. However, that light looks yellow to

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See the word“Sun”

elaborationArtistic of the Sun emitting a CME – coronal mass (Credits:ejectionNasa)

It’ssupergranules.thefrstlayerof

our eyes, due to the dispersive action of the particles of the terrestrial atmosphere.

chromosphere they are dominated by magnetic felds. The subsequent transition region is the area where temperatures (mysteriously) increase up to several billion degrees within a few tens of kilometers.

Then, we reach the Sun’s upper atmosphere, the coro na : it’s an area where the motion of the plasma is ruled by magnetic felds that emerge on the star’s surface, permeating the entire atmosphere, and is characte rized by temperatures which can reach up to million

Right after, we have the chromosphere, which owes its name to the shiny red color; its temperature can be above tens of thousands degrees °C, with a thick ness of over 1600 kilometers. It’s a difcult-to-study layer, due to its changing physical characteristics: in fact, in the low chromosphere, physical phenomena are dominated by the plasma, whereas in the upper

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TheCMEs.experts

keep them under control because they may be harbingers of space weather phenomena; they are the so-called flament eruptions. These are stre

They can last from a few days to several months, their width can be above 160.000 kilometers and they are

Among the turbulent events is also the solar fare, an energetic explosion of light and particles which is triggered by the sudden release of magnetic energy on the Sun. Flares are by far the most powerful explo sions in the solar system and their particles, which travel nearly at the speed of light, can reach Earth in less than 20 minutes.

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After exploring both the internal layers and those wi thin the solar atmosphere, let’s move to the “particu lar signs” of the Sun. Some of them behave in a parti cularly turbulent manner and make their infuence be felt also on Earth.

Another well-known phenomenon is the coronal mass ejection (CME), a large magnetic plasma cloud that is released in space after a solar eruption. The CMEs, which can also be million kilometers wide, expand in space and can collide and interact with the planets’ magnetic felds. In the case of Earth, they are at the origin of geomagnetic disturbances which give way to polar auroras, but also produce technical problems for the satellites and electric infrastructures which can be found on our planet.

degrees. The corona gives origin to the acceleration of the solar wind, as well as the fares and coronal mass ejections, that is the violent eruptions on which de pend the most intense space weather phenomena.

anwhite)(blackcoronagraphthe(inthetheobservationssimultaneousAlmostofcoronabyEUI/FSItoolyellow)andItalianMetisandshowextremely flamentous structure of the solar MetisOrbiter/EUIandCredits:corona.EsaNasa/Solarteam/team.

One of the most famous events is the solar wind: these are gusts of material which constantly fow from our star towards any direction. Such fow, which is less thick but faster compared to the terrestrial wind, is made up of charged particles (ionized electrons and atoms) which interact both with each other and with the solar magnetic feld. The wide area where the so lar wind spreads creates the heliosphere, the region where the Sun exerts its infuence within the inter stellar space. This sort of bubble “embraces” all the planets of the Solar System and acts like a protective shield, blocking several high-energy cosmic rays co ming from other parts of our galaxy.

amers of solar material, which is cooler and denser than what’s around it; when they become unstable, they may fall onto the Sun or disperse in space, pro ducing a coronal mass ejection.

Prominences are also quite lively: these are sna ke-shaped structures, made up of dense and cool so lar material, hanging on the Sun’s surface due to an intense magnetic feld. Prominences can occur when the magnetic structure becomes unstable and throw plasma outwards through the above-mentioned

connected to the trend of solar cycles: we’re talking about sunspots, cooler regions which appear on our star’s visible surface, and are caused by a concentra tion of magnetic feld lines which emerge, foating from the most internal layers of the star, and represent the most visible efect of the Sun’s large-scale magne tism, internally fueled by a huge dynamo. Scientists use these spots to follow the evolution of solar cycles.

Flux rope, instead, is the technical name with which solar physicists refer to all the concentrations of ma gnetic feld which emerge on the solar surface and, as a matter of fact, determine the overall magnetism of the solar atmosphere and its large- and small-scale behavior. The magnetic structures which emerge due to dynamo processes in the stellar interior can have sizes ranging from a few tens of kilometers, at the limit of the modern telescopes’ resolution power, to tens of thousands kilometers, as in the case of sun spots, which are the most evident, and historically the most famous, expression of solar magnetism.

Nanojets are thin and bright tendrils of plasma whi ch originate from impulsive release phenomena in the

It’s a patch in the Sun’s atmosphere, with a lower le vel of density: it’s the coronal hole, a region where the magnetic feld lines are directly connected to the interplanetary space. From this area, the material is dispersed in a fow of solar wind which blows at high speed, leaving a black hole next to the Sun’s surface.

elaborationArtistic of the solar wind (Credits:

E.–Orbiter/EUIand(Credits:SolarSunOverviewShirah)ImageConceptualGoddard’sNasaLab/GregofthebytheEsa’sOrbiterEsaNasa/SolarTeamDataprocessing:Kraaikamp)

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The coronal rain, instead, is made up of huge plasma globes which ooze out of the Sun’s external atmosphe re until its surface. This phenomenon happens in par ticular conditions: for example, when the confgura tions of the magnetic feld and local heating events in the corona make the plasma globes cooler and denser than the surrounding environment, causing a “rain”.

Plasma emissions which present themselves as grasslike tendrils: they are the so-called spicules, plasma streams which leave the solar surface at tens of kilo meters per second and, before collapsing, can extend for over 9.000 kilometers, transferring energy and material to the most external layers of the atmosphere.

energy accumulated by magnetic felds, like rubber bands which are twisted on themselves by the mo tion of photospheric plasma. They extend for thou sands of kilometers and are generated by nanofares, tiny explosions produced by a phenomenon known as magnetic reconnection, which happens when the ma gnetic feld lines are “tangled”.

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Our journey to the discovery of the characteristic traits of the Sun ends with the granules and the su pergranules, which are networks of cells covering the visible surface. Their size is a thousand kilome

Their code name is Seps (Solar energetic particles): these are highly charged particles – mostly electrons and protons – and accelerated by the activity on the Sun. The acceleration can happen in conjunction with solar fares or in space. Seps, whose motion is guided by magnetic felds, are a dangerous source of radia tion for astronauts and make themselves felt also on Earth’s atmosphere, where they can hinder high-fre quency radio communications like GPS.

Orbiter have been active, respecti vely, from 2018 and 2080 and they are working to un ravel new details about the Sun and create a few un published “portraits”. In May 2022, the Solar Orbiter released the closest images of the Sun ever taken, and with unprecedented detail: this successful result has been obtained also thanks to the Metis coronagraph, funded and managed by the Italian Space Agency. Such tool has been created, designed and manu factured by a team made up of the National Institute for Astrophysics, the universities of Florence and Pa dua, the Cnr-Ifn and an Italian industrial consortium made up of Ohb Italia and Thales Alenia Space Italia.

Solar fare observed by the Nasa Sdo mission (Credits: Observatory)Solar(Credits:NasaobservedFilamentGoddard)Nasa/Sdo/eruptionbytheSdomissionNasa/Dynamics

It resembles the trend of the water spread by a rota ting irritator: it’s a structure defned as Parker spiral, produced by the solar magnetic feld when the Sun ro tates and the magnetized solar wind blows outwards.

They present themselves as streamers of material that stretch out from coronal holes on the Sun’s surface: they are the so-called plumes, which appear bright in extreme ultraviolet views and are made up of smal ler streamers (plumelets). Plumelets play a key role in creating the high-speed solar wind.

Parker(supergranules).andSolar

ters (granules) or 25.000 kilometers (supergranules) and they are produced by the convection motions of the solar material. They can be seen, respectively, for 8-10 minutes (granules) or up to a few hours or days

Also the Sun has a “seismic-like” activity: sunquakes are phenomena which produce ripples on our star’s surface, similar to those of terrestrial earthquakes. This phenomenon, whose root cause is not yet known exactly, accompanies some solar fares.

anotherunderLivingstar

Last March, the number of discovered planets around other stars, the so-called extrasolar planets or exoplanets, passed the 5000 mark. Ob viously, there’s nothing special in such fgure, but it’s a remarkable goal, particularly if we think that, only thirty years ago, the only worlds we knew were the few which keep company to the Earth in its orbit around the Sun. Since 1995, the year of the discovery of the frst planet around a star like ours, the total has been growing at impressive pace. If we project this statistical data to the hundreds of billions of stars which make up our galaxy, the Milky Way, we reach the conclusion that virtually each of them hosts a planetary system.

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Among the thousands of known exoplanets, there are quite a few which don’t have a counterpart in the solar system: for example, the so-called “Super-Earth planets”, which represent the middle range between our by Amedeo Balbi

Furthermore,saga.

So, we might be tempted to defne our planet as a statistical abnormality. However, when we consider the issue with more attention, we realize that things aren’t as simple as they may seem. Are we really sure

system.Trappist-1ofofrepresentationAnNasa-JPL/Caltechsystemstar’sofrepresentationArtistictheTrappist-1planetaryCredits:artisticthesurfaceaplanetofstar

planet and Neptune, or the “warm Jupiters”, which are big, gaseous and very close to their star. However, these aren’t the only diferences with our planetary system. There are planets which orbit around extreme objects such as neutron stars, and even around double stars, like the Tatooine planet does in the Star Wars

the Earth orbits around a type of star which is not particularly common. The stars which are smaller and fainter than the Sun, known as red dwarfs or, technically, as M-type stars, are much more numerous. In absolute terms, these stars are the most abundant in our galaxy, and are nearly fve times more common than Sun-like stars. And not only that: they also live way longer than our star, and their average life is dozens of times higher. So, the most common planets in the universe are most likely those with a reddish sun in their skies.

The planets around the red dwarfs are also relatively easier to discover. In fact, the observation techniques tend to be more efective if the host star is small and

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weak, particularly when we’re searching for Ear th-size planets in the so-called “habitable zone”. This zone is simply the region of a planetary system which favors the stable presence of liquid water, one of the requisites which are regarded as essential for life as we know it. In fact, the majority of the potentially ha bitable exoplanets which were discovered in the last decades is located in orbit, just around M-type stars. This is the case, for example, of the rocky planets or biting around the Trappist-1 star, a red dwarf located nearly 40 light years away from the Sun: three out of the seven planets discovered in 2017 in that system fall within the habitable zone. Even the closest po tentially habitable extrasolar planet orbits around an M-type star, Proxima Centauri. More in general, as many as 18 out of the 20 terrestrial exoplanets in the habitable zone, which we know as of today, orbit around a red dwarf.

SPAZIO 2050 | 15 the tion.thethesystemplanetarywhetherunderstandlightshedhelpstudiestheoreticaltionsobservafuture-andwillustosomeandourisruleorexcepNasa/Jplsystem.Trappist-1thecandidateplanet,theaagencyNasa,posterPromotionalbythewheretheimaginesjourneytoTrappist-1ethebesttohostlifeofthestar’sCredits:

Being at short distance from a red dwarf has another consequence: the gravitational interaction with the star leads the planet to synchronize its orbital period with the rotation period. In simple terms, the planet ends up always showing the same side to the star, just like the Moon does with the Earth. Therefore, a hemi

The frst factor to be considered is the distance from the star. Red dwarfs are not very bright, therefore the potentially habitable zone is very close to the star, typi cally at a smaller distance than that between Mercury and the Sun. This is not good news, unfortunately. In fact, M-type stars are way turbulent than ours, and re lease frequent rushes of energy: ultraviolet radiation, X-rays and charged particles, which can be extremely harmful for living organisms. Furthermore, in the long run, such violent events may deprive a planet whi ch is too close to the star from a substantial part of its atmosphere, making it even more hostile to life.

If to all this, we add the fact that the poor luminous in tensity may inhibit the photosynthesis and formation of biologically relevant molecules, it would look like red dwarfs, overall, are less suitable to host habitable planets than Sun-like stars. This may explain why we aren’t orbiting around the most common type of star in the galaxy. However, the verdict is not fnal yet. We have just started to investigate the complicated fac tors which make a planet habitable: among them, the characteristics of the star itself surely play a not insi gnifcant role, although the latter hasn’t been yet fully understood. The future observations and theoretical studies will help us to shed some light and understand whether our planetary system is the rule or the excep tion

that life is possible around an M-type star? In the past years, several theoretical studies have tried to answer this question.

sphere is constantly enlightened, whereas the other one is always in the dark. Not only the lack of alterna tion between night and day may be incompatible with life, but the planet’s metal core might not be mobile enough to produce an intense magnetic feld. This would make the planet’s surface and its atmosphere even more exposed to the harmful cosmic radiations.

Telespazio has embodied the concept of Open Innova tion for some time, starting from the belief that the dialogue with startup companies, research centres and universities is a key element of the success of a big company. Starting from 2019, and with this belief, Telespazio and Leonardo have created the #T-Tec, the Telespazio Technology Contest, dedicated to students and researches, with the aim of promoting technolo

Open InnOvatIOn: the 2022 edition of the #t-teC telespazio kiCks off

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by Marco Brancati Telespazio SVP Innovation and Technological Governance

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«Any sufciently advanced technology is indistingui shable from magic». These are the words of Arthur C. Clarke, known to many as the writer and screenwri ter of 2001: A Space Odyssey and the father of satellite telecommunications. In 1945, when Clarke’s article was published in the Wireless World magazine, the idea that satellites placed in a geostationary orbit could put in communication every point on the globe looked like pure science fction. Almost eighty years later, that in tuition has completely changed the way we live.

think to have all the internal skills required to keep up with a constantly evolving world.

Innovations have this power. They accelerate reality, they shape it, until reaching unexpected goals. All of this is particularly true for the space sector, whi ch has switched from an isolation that was typical of its pioneering stage to a continuous dialogue, not to say permeation, with the digital world and the several specialist niches that make it up.

It doesn’t matter how big a company is, and how much experience it has in the feld. Today there’s no com pany, in the space and non-space sector, that can

gical innovation in the space sector among the youn ger generations, promoting their ideas and intuitions and imagining together the technologies that will shape our future.

partnerships with important universities have been facilitated by the participation of their respective teams in the #T-TeC. Also this year, the #T-TeC can boast prestigious sponsorships: “historic” sponsors such as the Italian Space Agency and European Space Agency will be joi ned, for the 2022 edition, by the Italian Association of Aeronautics and Astronautics (Aidaa) and internatio nal sponsors such as the Space Generation Advisory Council in Support of the UN Programme on Space Applications (Sgac) and the Council of European Ae rospace Societies - (Ceas). As well as giving further prestige to the initiative, such sponsorships will al low even more to make a way into the academic world and the world of national and international research; in the three past editions, 57 innovative proposals were submitted by 200 participants among students, PhD students and researchers coming from 30 global Alwaysuniversities.Clarke thought that the only way to discover the limits of the possible is to go beyond them into the impossible. Ultimately, the #T-TeC, and more in general the Open Innovation, perform this extremely difcult task: to draw a line somewhere just to be able to cross it.

Each company must set itself the goal of giving value to ideas. Contests such as the #T-TeC are valuable opportunities to create connections with innovative realities, exchange opinions and, sometimes, disco ver talents.

Same as the previous editions, the three winning te ams will receive checks of diferent amounts, based on the achieved result. The judging panel, which will be made up also of representatives from the Italian and European Space Agency, will also select a few special mentions and will assess the possibility of funding the most promising ideas by means of rese arch contracts or partnerships.

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In the last three years, Telespazio has welcomed two participants in the past editions of the #T-TeC, who currently work on some of the most innovative projects conducted by the company, such as the study for the manufacturing of a lunar communication and positioning Furthermore,system.afew

Leop

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Space; GeoInformation Applications and Platforms for a sustainable Earth, Space Domain Awareness for the Protection of Space and Ground Infrastructures; Secure and Resilient Communications with future technologies; Positioning, Navigation and Timing Infrastructures and Solutions for Earth and other celestial bodies. These are important topics, which will increasingly infuence our daily life in the coming years and decades.

In particular, starting from this year, Telespazio has decided to turn into an actual incubator for startup companies. If they wish so, the winning team will be able to access an acceleration process for the next stages of the awarded project.

For the 2022 edition of the #T-TeC, the competing teams will discuss six technological macro-themes which are relevant for the present and the future of the space sector: Space and Extraterrestrial Explora tion; In Orbit Servicing towards a Circular Economy in

THE SOLAR ITALY

SOLAR ORBITER

NASA2018 mission. Overall, the closest probe to the Sun so far for the study of the solar corona. Italy provides support to the exploitation of scientiﬁc data. SOHO A1995joint ESA-NASA mission for the study of the Sun and, in particular, the tempe rature of the solar corona. The spectro meter in the visible channel of the UVCS ultraviolet coronagraph is Italian. All the missions dedicated to the study of our star, to which Italy contributes by providing scientiﬁc tools or support Present missions Future missions

An2020ESA mission dedicated to the study of the internal heliosphere, the solar wind and the polar regions. Italy contri butes with the Metis coronagraph, the data processing unit (DPU) of the SWA tool for the data analysis of the solar wind and the image reconstruction software of the Stix tool.

PARKER SOLAR PROBE

By Manuela Proietti

Infographic Infolab CSES-1 Chinese-Italian2018 partnership to study the seismic precursors and electromagnetic phenomena related to the space weather. The Italian contribution, named as Limadou, consists of the Hepd-01 particle detector and the participation in the manufacturing of the Chinese E-01 tool. CSES-2 In2023the second mission of the Chinese-I talian partnership, the Italian contribu tion grows: through the ASI, Italy provi des the Hepd-02 particle detector and the Efd-02 electric field detector. MUSE A2027NASA mission dedicated to the study of the solar dynamics, Sun-Earth connection and space environment. Italy is in charge of manufacturing the telescope’s mirrors and the multi-layer filters, as well as providing support to the coating and scientific support. SOLAR-C EUVST 2027Japanese-led mission to unravel the formation mechanisms of hot plasma and the effects of the solar activity on Earth and the Solar System. Italy manu factures the slit system of the spectro meter and provides scientific support. PROBA 3 ESA2023technological demonstrator for the formation flying of high-accuracy Italysatellites.isin charge of the positioning system and provides scientific support.

The Esa-Nasa mission to explore our star and Italy’s role in this fascinating journey to discover the Sun by Giulia Bonelli

GLOBALSCIENCE.IT OrbiterwiththeTouchingSuntheSolar 20 | SPAZIO 2050

Italy aboard the Solar Orbiter. The Asi’s Metis tool is Italian: it’s a coronagraph which has been manufactured in partnership with the Inaf, the Cnr and the universities of Florence and Padua, and with the contribution of the Max Planck Institute for Solar System Research (Germany) and the Astro nomical Institute of the Science Academy (Czech Re public).

«Metis is the frst tool of its kind which is able to ob serve simultaneously the Sun and the most extended solar corona in several bands of the electromagnetic spectrum, in the visible and ultraviolet spectra, and allows to obtain a set of highly innovative analyses. For example, we’re mapping for the frst time the expansion speed of the plasma in the whole coro na, and we’re obtaining very high resolution ima ges», explains Marco Stangalini, ASI researcher and Project Scientist of the Metis tool.

The long scientifc research related to the Sun is also accompanied by fascination and fear and today is the object of several international space missions. The Solar Orbiter, the Esa-Nasa probe which, astrono mically speaking, got a stone’s throw from the Sun, wanders here, in this extreme cosmic environment. It took two years for the Solar Orbiter, which depar ted in February 2020 from Cape Canaveral aboard an Atlas V carrier rocket, to make its frst close en counter with the Sun. During its journey towards our star, it made spectacular images, such as the Venus – Earth – Mars triplet, which was immortalized in an unprecedented overview, to then reach our star and start to study it with its ten scientifc tools.

SPAZIOWWW.ASI.IT2050|21medialab.Credits:OrbiterofrepresentationArtistictheSolarprobe.Esa/Atg

Since the prehistory, the Sun has been at the same time venerated and feared. In several ancient cultu res, our star is the most important divinity, and the Egyptians regarded the Pharaoh as the son of the Sun, whereas in the Greek myth of Icarus the young son of Daedalus ignores his father’s warnings and gets too close to the boiling star: his wings, held to gether by wax, melt and make him fall down.

«The Solar Orbiter – explains Barbara Negri, head of the Asi’s Human Flights and Scientifc Experimenta tion unit – can be regarded as a scientifc breakthrou gh mission, or as a turning point: it’s exploring the solar corona, and will observe our star from a di stance never reached before by other probes. We’re talking about a highly prohibitive environment, with temperatures up to 500° C, whereas up to -200° C can be reached in the shady side. Because of this, Thales Alenia Space has manufactured in Turin a really in novative heat shield to protect the Solar Orbiter’s ten scientifc tools: six remote-sensing tools, to observe solar phenomena as a whole, and four in-situ tools, which carry out punctual analyses of the corona’s

There’senvironment”.alotmore

ASI researcher and Project Scientist of the Swa tool. Before the launch of the Parker Solar Probe and Solar Orbiter solar missions in the last few years, the last mission dedicated to the in-situ analysis of solar wind in the internal heliosphere dates back to 1975: it’s the pair of Helios probes, launched by the German Dlr in partnership with the Nasa.

«Still today – explains Perrone – we continue to publi sh the data collected by Helios, but we can’t compare the resolution of such data with what the Solar Orbiter will be able to reach. Swa and the other in-situ tools will allow to obtain information on what we call kine tic efects: very low-scale phenomena which, however, may have a big impact on the overall solar dynamics. For example, they may help us to explain the issue of

These images show the Sun as we had never seen it before. At the end of March 2002, the Solar Orbiter completed its frst close pass and reached up to a di stance of less than 50 million kilometers away from our star. Nearly two months later, the Esa published the frst photographs: a set of breathtaking pictures of the Sun and, even more importantly, a goldmine of scientifc data, several of which have been collected by Metis, which has allowed to explore extreme phe nomena, such as the violent expulsions of coronal mass. One of these eruptions has been immortalized during the last overfight of the Sun: the Solar Or biter has captured the “journey” of a solar eruption, starting from the superfcial layers of the atmosphe re until its explosion in space.

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Metis explains the origin of fuctuations in the solar wind

Thirty years after the frst discovery of sudden fuctuations in the magnetic feld of the solar wind, by the Nasa-Esa Ulysses mission, the measurements carried out in 2021 by the NASA Parker Solar Probe mission had highlighted a surprisingly high amount of such events. This had led to the formulation of several hypotheses on their origin. Such fuctuations are actual inversions of the magnetic feld which, as if they were under the effect of a whip, propagate in the interplanetary space. Today, just slightly over one year after the Parker’s observations, the Italian Metis coronagraph, aboard the Solar Orbiter, has directly observed for the frst time one of these fuctuations, the so-called switchbacks, in the solar corona. The result was obtained thanks to the data acquired immediately after the beginning of the nominal phase of the Esa probe, in March 2022.

The data obtained by Metis, which are currently being published in the Astrophysical Journal Letters, show the propagation of one of these disturbances of the magnetic feld in the solar corona and have fnally allowed to discriminate among the different possible mechanisms of formation that have been proposed so far and create a relationship between this type of processes and the acceleration of solar wind.

«Metis – continues Stangalini – observes the most extended solar corona. But obviously, what we obser ve in the corona is the result of the energy coming from the most internal layers of the solar atmosphe re. These layers are observed by other tools aboard the Solar Orbiter, such as Stix, an X-ray spectro meter-telescope for which Italy has provided the software for images reconstruction. Therefore, by combining all the information obtained by the dife rent tools, we can better study the physical processes happening in the solar atmosphere. We manage to follow the solar energy, which is responsible for the expulsions of coronal mass that can have an impact also on the interplanetary space».

«Swa is a suite of tools which allow to measure the particles of solar wind. It’s made up of a tool which measures electrons, a tool which measures protons and alpha particles and another one which measures heavy ions. Finally, there’s the Data Processing Unit (Dpu), which is the core of the tool and is under the Italian leadership. Swa allows an in-situ calculation of the characteristics of solar plasma, such as densi ty, speed and temperature, and characterizes the en vironment in which the probe is immersed. An actual cosmic laboratory experiment», says Denise Perrone,

Composite image of the solar disk, observed ultravioletinlight by the Eui tool aboard the Solar Orbiter and the (blue) corona Metis.simultaneouslyobservedbyTheyellow box identifes the coronal perturba tion observed at high resolution by Metis. From Telloni et al. 2022 (in press ApJL).

Solar 2022.ontheimmortalizederuptionbySolarOrbiterMarch2nd,Credits:Esa & Nasa/Solar Orbiter/ Eui & Stix Teams.

«These phenomena of the solar corona – adds Barba ra Negri – are capable of damaging satellites orbiting around the Earth, and also of putting at risk several activities on our planet. Therefore, observing closely the mechanisms which lead to the expulsion of co ronal mass and other similar phenomena is a unique opportunity, which will allow us to collect new clues on space weather and study appropriate counterme asures».

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In these months, the scientifc community is working incessantly on the data collected by the Solar Orbi ter. But several precious data have yet to arrive: it’s the data obtained from in-situ tools, which directly collect particles coming from the Sun. Among them is the Swa tool, an acronym for Solar Wind Analyzer, with a signifcant contribution from Italy.

the abnormal heat of solar wind. Since we’re talking about an expanding gas, we expect solar wind to cool down as it approaches space, but previous data show that such cooling doesn’t happen at the expected spe ed. This means that there must be a local source of energy which heats the plasma and may be related to kinetic efects. Thanks to the Solar Orbiter, we hope to add new information to fnd an answer».

collected from the probe already lead us to think of a potential role of campfres, tiny eruptions which are ubiquitous on the solar surface. They may be related to a process which is capable of contributing signif cantly to the heating of the solar corona: such data, if confrmed by the Solar Orbiter, would explain one of the big mysteries of solar physics.

First pictures of the solar corona obtained by the Metis graphcoronaaboard the Solar Orbiter on May 15th and June 21st, 2020. Credits: Esa & ter/Eui&2022.onlion.OrbiterfromTheTeam.Orbiter/MetisNasa/SolarSunseentheSolaratperihePicturetakenMarch26th,Credits:EsaNasa/SolarOrbiTeam.

We expect many other discoveries from this revolutio nary mission a stone’s throw away from the Sun, whi ch combines science and technology with an unpre cedented level of innovation to study our star. Another great enigma which may be solved thanks to the So lar Orbiter is the diference of temperature between the corona and the surface of the Sun. The frst data

Again, several expectations are linked to the explora tion of the Sun’s poles: as of today, this region is com pletely uncharted, and the Solar Orbiter will be able to observe it when inclining its orbit.

But before that, starting from next October, we expect further and spectacular overfights of the Sun, which will ofer us new data and new images, capable of mo ving also who’s been studying our star for his whole life.

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Solar Probe was launched almost four ye ars ago, on August 12th, 2018, from the Cape Canave ral space center, in Florida, and will end its journey in 2025. Over almost seven years, the probe will orbit around the Sun for a total of 24 hours; each orbit’s pe rihelion, the point of closest approach to the Sun, will be gradually reduced by taking advantage of Venus’s gravity, in proximity of which the space vehicle will transit seven times overall. The minimum distance from the solar surface that the Parker Solar Probe is expected to reach is 6.1 million kilometers – approxi mately ten times lower than the average distance between Mercury and the Sun. It may seem a mission impossible, since the solar corona reaches temperatu res around one million degrees Kelvin. How can the equipment aboard the probe and the vehicle itself withstand such a hostile environment and, above all, the fusion? As a matter of fact, the solar corona has an extremely low particle density: while crossing it, the Parker Solar Probe runs into such a low number of particles that the amount of heat transferred by them to the vehicle is capable of heating its surface “only” up to a temperature of 1104 K. Most equipment abo ard the probe is protected by a thermal shield, which has a thickness of 11.5 centimeters and maintains such equipment approximately at room temperature; the

outdoor equipment is built with metals whose fusion point is almost 1000 K higher.

What is the most direct way to study the Sun, except for touching it? Contrarily to what the extremely high temperatures reached in the solar atmosphere may lead us to think, it’s not madness, but the pure rea lity. The primacy belongs to the Nasa and its Parker Solar Probe, the frst space probe in history to cross the Sun’s corona, the most external layer of its atmo

The Parker’sjourney

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The data collected by the tools aboard the Parker So lar Probe are one of a kind. In fact, the Sun is the only star that we can study so closely and that has such an important impact on our planet. Solar activity is de clined in an amount of phenomena which involve Ear th and the surrounding space and give origin to the conditions which make up the so-called space weather The solar wind, the fow of charged particles produ ced by the incessant expansion of the Sun’s corona, plays the main role. The solar wind interacts with the terrestrial magnetosphere, the magnetic shield which

by Luca Mingotti Landriani

Image of a coronal Probe.NRL/ParkerPhoto:imagetheobjecttool.Probe’sParkercaptured2018NovemberoftheobservedstreameraboveEasternedgetheSun,on8that6:12UTC,bytheSolarWisprThebrightnexttocenteroftheisMercury.Nasa/Solar

Thesphere.Parker

Last June 2nd, the Parker Solar Probe completed her twelfth perihelion. The mission is now at its turning point, but the enthusiasm for the potential, upco ming discoveries is not decreasing because of this. After all, it’s no coincidence that the probe symbo lically bears the name of a pioneer of the Sun’s phy sics – Eugene Parker, who passed away this year, on March 15th. After the great steps taken by the Ame rican astronomer, to whom we owe the frst theory capable of explaining the dynamics of the solar wind, the Nasa mission represents a unique opportunity to revolutionize the landscape of the star which gua rantees our own life.

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origin, in order to expand the knowledge of a few me chanisms that concern them and haven’t been clari fed yet. In this way, it would be possible to improve the current monitoring and protection systems from the corresponding space weather events.

protects Earth from the dangers of the interplanetary space and sometimes causes alterations of the Earth’s magnetic feld, which are refected in the malfunctio ning of electric networks, communication systems and satellites. The extent of such phenomena increa ses substantially when the Sun ejects a whole portion of material from its corona – a phenomenon known as coronal mass ejection. The acceleration of high-energy charged particles, known as solar energy particles, is linked to this ejection; they represent a serious danger for the safety of astronauts and the correct functio ning of the orbiting devices. In addition to the merely scientifc goals, the Parker Solar Probe aims at inve sting the environment where such events have their

Already a few months after the launch, the Parker Solar Probe has fown over some structures, known as coronal streamers, from which coronal mass ejections are believed to be forming. In 2019, the pro be discovered the difuse existence of zigzag conf gurations of the solar wind, known as switchbacks, in the proximity of the star. Only two years later, their region of origin was identifed: it is located in the proximity of the Sun’s surface. Should we be able to understand the relationship between the onset of these structures and the formation of the fast com ponent of the solar wind, we would fnally be able to solve a mystery which has been gripping scientists for a long time: how does the Sun’s corona reach way higher temperatures than the Sun’s surface?

Photo: Ingalls.Nasa/Bill

The launch of the Parker Solar Probe with a Delta IV Heavy rocket from the Cape Canaveral Air Force Station, in Florida (USA), on August 12th 2018 at 7:31 UTC.

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nEEugEnEwmanParkEr, the pioneer of heliophysics

It also measured the interplanetary dust, which tur ned out to be less than expected, and detected high-e nergy charged particles coming from the Sun, inclu ding a few brief solar fares, and also a few cosmic rays coming from the outer Solar System. His theories and mathematical models talked about conditions which generated the supersonic fow of particles from the Sun’s surface. “Well I would suggest that Parker go to the library and read up on the subject before he tries to write a paper about it, because this is utter non sense”: this is what Parker recalled in an interview for the UChicago News in 2018, quoting one of the har sh comments coming from the scientifc world about his advanced theories. He was elected to the National Academy of Sciences in 1967, and was a member of the American Physical Society and Legacy Fellow of the American Astronomical Society; during his long career, he was the author of important publications. The testimony of Nicky Fox, director at the Nasa, on Parker’s genius is particularly impressive: «Known as the father of heliophysics, Gene’s discoveries are foundational to what we know about space weather and how stars behave. His level of brilliance is rare. He described the discovery of the solar wind as “simple.” It was derived from just four lines of algebra». Gene passed away last March 15th, after having his revenge with the Nasa Parker Solar Probe mission, which was launched in 2018 to observe the Sun’s outer corona and bears his name. It’s the frst Nasa space vehicle named after a living person.

Emeritus professor and great revolutionary thanks to his theories about the Sun: he leaves us a mission which bears its name, and an example of the genius of imagination

ctions were confrmed by satellite observations a few years later, especially by the Mariner 2 mission, a Nasa space probe launched on August 27th, 1962, towards Venus. During its path, the probe measured the solar wind and confrmed the measurements conducted by the Luna 1 probe in 1959.

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by Giuseppina Pulcrano

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Eugene Newman Parker, a life spent among innovati ve theories and irrefutable evidences of his vision on the studies of the Sun. Gene, as he was afectionately called by the Heliophysics Division Director, Nicky Fox, had a sweet and kind face and leaves us an in delible heritage on how challenges should be faced in life, generally speaking, and in particular in the work of a scientist: «If you do something new or innovative, expect trouble. But think critically about it because if you’re wrong, you want to be the frst one to know that». A sort of will for young scientists: he left it in the year of the launch of the Parker Solar Probe mission, which he attended at the age of almost 91, when he was already ill, accompanied by three generations of his family and by the Nasa team. He was clear headed, determined and a dreamer and his innovative theo ries have been the object of criticisms, which were not always respectful, by representatives of the interna tional community. Parker graduated in Physics at the Michigan State University in 1948 and obtained a PhD in Philosophy at the Caltech in 1951.

He spent four years at the University of Utah, before joining the University of Chicago in 1955, where he spent the rest of his career. After obtaining this pre stigious teaching post, in the mid 1950-s, Parker deve loped the theory of the supersonic solar wind and pre dicted the Parker spiral shape of the solar magnetic feld in the outer Solar System. His theoretical model ling wasn’t immediately accepted by the astronomi cal community. When he submitted the results to Te Astrophysical Journal, two reviewers recommended its rejection. The editor of the journal, Subrahmanyan Chandrasekhar, couldn’t fnd a fault in Parker’s ma thematics and overruled the reviewers. Chandra sekhar, a future Nobel Prize, courageously decided to publish the paper anyway. Parker’s theoretical predi

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These are some of the investigation felds of the Chi nese Space Agency’s Cses (China Seismo-Electroma gnetic Satellites) satellites, whose goal is to identify electromagnetic, ionospheric and magnetospheric seismic precursors and study possible space-time correlations with the arrival of high intensity earth Inquakes.fact, several studies have highlighted the possi ble existence of cause-efect relationships between electromagnetic emissions, related to Earth’s seismic activity on the one hand and the occurrence of per turbations in the iono-magnetospheric plasma on the other hand.

In particular, the data obtained by the Cses on the magnetic feld and energy particles were added to two global multi-tool analyses on geomagnetic storms in August 2018 and May 2021, showing the huge capa city of the Cses, in the feld of space weather, to un derstand the dynamics of Van Allen radiation belts in connection with solar forcing. Furthermore, the Hepd has measured for the frst time in the ionosphere, at 500 km altitude, the fow of low-energy cosmic pro tons with great accuracy, providing a key contribution to the understanding of the interplanetary magnetic feld. Lastly – adds Piersanti -, thanks to the extre me sampling frequency of the electric feld detector (Efd), we have been able to identify, for the frst time, the small spatial-scale fuctuations of the electric feld when entering the auroral oval, where charged parti cles interact with the terrestrial ionosphere». The Cses-01 satellite has nine scientifc tools abo ard, designed to measure the magnetic feld, the pro

by Manuela Proietti

An artistic presentationre of the Hrybyk-Keithter/MaryFlightGoddardCredits:gnetosphereterrestrialSunbetweeninteractiontheandthemaNasa’sSpaceCenPat

amount of data, whose analysis has led to a better un derstanding of the magnetosphere-ionosphere cou pling mechanisms during periods of high solar acti vity.

Cses-Limadou hunting for earthquakesfromspace

«From a scientifc standpoint, the evaluation of the frst four years of fight of the Cses satellite – says Mirko Piersanti, scientifc director of the Li.M.I.C., Lithosphere – Magnetosphere – Ionosphere Coupling research group – is extremely positive. The Hepd, along with the other payloads, has transmitted a huge

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Cses-01, launched on February 2nd, 2018, aboard a Chinese carrier rocket, has already started to provide the frst answers, in particular thanks to the Hepd-1 high-energy particle detector, one of the Italian con tributions to the Chinese mission.

Is there a correlation between earthquakes and geo magnetic storms? Do seismic events have an impact also on the space environment? Is it possible to moni tor an earthquake from space?

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The Infn – with its branches of Bologna, Napoli, Pe rugia, Roma Tor Vergata, the Tifpa-Trento centre and the National Laboratories in Frascati – is the Asi’s

A second satellite, the so-called Cses-02, will be lau nched in 2023, and a higher contribution is expected. «The excellent results reached in the frst mission and the strong expertise of our scientifc communi ty – explains Simona Zofoli, Program Manager for Limadou at the Asi – have allowed the Asi to stren gthen its participation in the Cses-02, the second mission which, along with the Cses-01, will create the frst core of a satellite constellation, which will be in charge of a new type of remote sensing. In this second mission, the Italian cooperation will not only provide an updated version of the particle detector, the Hepd-02, but also the tool to measure the electric feld, the Efd-02, which in the frst satellite had been manufactured by the Chinese partner».

main partner in its cooperation with the Cnsa. The Inaf-Iaps of Rome, the universities of Bologna, Pe rugia, Roma Tor Vergata, Trento, the International Telematic University UniNettuno, the Ifac/Cnr and the National Institute of Geophysics and Volcanology are also involved in this cooperation, with their own scientifc expertise as regards data analysis and de velopment of geophysical models.

The in-orbit operations are carried out from the Chi nese ground stations, whereas the scientifc data are stored and distributed by the Asi Ssdc data centre.

perties of the ionospheric plasma and the fow and spectrum of high-energy particles: for the frst time, all the main sensors required to study the ionosphere, magnetosphere and their possible coupling are abo ard a single satellite.

The orbit of the satellite is Sun-synchronous and is located at approximately 500 km altitude. The Italian contribution for the Cses-01, which is governed by an agreement between the Asi and the Chinese Space Agency, is called Limadou in honor of the Italian Je suit missionary Matteo Ricci – whose Chinese name was, in fact, Li Madou – consists in manufacturing of a payload, the High Energetic Particle Detector (Hepd1), and supporting the manufacturing the Electric Field Detector (Efd), as well as conducting the plasma chamber tests for the Efd and other tools manufactu red by the Chinese partner.

Cses-02 will create the frst core of a satellite constellation, which will be in charge of a new type of sensing.remote

tance Review, which will be followed by the transfer of the satellite to Kourou, in French Guyana, to start the launch campaign. Thanks to the cold gas microthru sters manufactured by Leonardo, the Esa will be able to control the probe’s orientation in space with infni tesimal corrections of the observation direction. The information on the telescope’s line of sight will also come from a Leonardo sensor: the Fine Guidance Sen sor (Fgs). Finally, Leonardo provides the photovoltaic panels, which will provide power for all the probe’s systems. «I would like to emphasize the excellent work carried out over the last few years by both the project team and the entire industrial consortium for the Esa Euclid mission – said Walter Cugno, Vice-President of Exploration and Science at Thales Alenia Space -, a very synergic and punctual work that confrms Thales Alenia Space’s ability to lead the development of hi ghly challenging scientifc missions, such as this one. A special thanks goes to the team which, with the con tributions from Spain, Belgium and France, enabled Thales Alenia Space to reach this important program milestone, which will be now followed by the environ mental tests carried out in Cannes and the beginning of the launch campaign».

Euclid is a European Space Agency (Esa) mission for astronomy and astrophysics, aimed at investigating the nature of dark matter and dark energy with the important contribution of the Italian Space Agen cy (Asi) and the French Space Agency (Cnes). Thales Alenia Space (a joint venture between Thales (67%) and Leonardo (33%)) is the prime contractor for the manufacturing of the satellite, leads an industrial consortium made up of the largest European space companies and takes advantage of the scientifc con tributions from universities and specialized research centres. Euclid will analyze how the universe has evol ved in the last 10 billion years to better understand the dynamics of its expansion and why it is accelera ting. Euclid’s launch is scheduled for 2023; the mis sion will last 6 years around the L2 Lagrange point, located 1.5 million kilometers away from Earth. As of today, all the satellite integration activities have been completed at the Thales Alenia Space factory in Turin, whereas the environmental tests before the launch campaign will be conducted at the Thales Alenia Spa ce factory in Cannes. Following the individual inte gration and testing of the on-board sub-systems and the Vis (Visible Instrument) and Nisp (Near Infrared Spectrometer and Photometer) scientifc tools, now the telescope, which had previously been integrated at the Airbus factory in Toulouse, has been installed in the service module and the solar panel and antenna have also been integrated. The next stage will be the fnal acceptance tests of the satellite and, in particu lar, the functional tests in the thermal vacuum cham ber, the acoustic and sinusoidal mechanical tests and the electromagnetic compatibility tests. The next re view and decisive moment will be the Flight Accep Light

by the ASI’s editorial staf

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Euclid will study how the Universe has evolved over the last 10 billion years.

the integration of the satellite, which will explore dark energy and delve into the mysteries of dark matter, is now completed

GLOBALSCIENCE.IT2050

on the withuniversedarkeucLid

WE BELIEVE IN SPACE AS HUMANKIND’S NEW HORIZON TO BUILD A BETTER, SUSTAINABLE LIFE ON EARTH SPACE FOR LIFE

In more detail, the spectrometer has allowed to know more specifcally some physical parameters of the solar wind: expansion speed, kinetic temperatures, speed distribution of minor protons and ions and chemical composition.

The scientifc andinoftechnologicalcontributionourcountrytheesa/nasasohomission

the universities of Florence, Padua and Turin and the Harvard-Smithsonian Center for Astrophysics.

soho mIssIon by Fulvia @asi_spazioCroci

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The Uvcs has allowed to analyze in more detail the ul traviolet solar corona until its most external layers, unraveling the regions where the solar wind is ac celerated. The tool has also detected the most likely energy deposition processes which guide the wind, diferentiating it between fast wind (800 kilometers per second) and slow wind (400 kilometers per se cond). In particular, the Uvcs has led to the discovery of diferent kinetic temperatures for diferent ions, whose values, unexpectedly, are hundreds of million degrees higher than electrons and hydrogen in the corona. This has been suggestive of heating and ac celeration mechanisms of the solar wind, related with the resonance interaction between magnetic feld wa ves and plasma.

Italy has contributed signifcantly to the mission, by designing and manufacturing the Uvcs spectrometer in the visible channel of the ultraviolet coronagraph (Uv Coronagraph Spectrometer), which measures the density and temperature of the corona. The tool, f nanced by the Nasa and the Italian Space Agency, is a fagship of our country’s scientifc excellence and has been manufactured thanks to the partnership between the National Institute for Astrophysics (Insf),

If today Italy is aboard one of the main Sun observa tion missions, the Solar Orbiter, it defnitely owes it to the expertise developed thanks to the participation in the Esa/Nasa Soho mission.

wreachesItalythesunIththe

The Solar and Heliospheric Observatory was launched in 1995, at 1.5 million kilometers from Earth. From this point of observation, Soho constantly observes the Sun, returning spectacular images and data of the storms that rage on its surface. Soho’s studies range from the Sun’s interior, through its visible surface and atmosphere, to distant and difcult-to-observe regions, where the solar wind clashes with the atoms and the elements coming from the other stars.

The Large Angle and Spectrometric Coronagraph (Lasco), instead, is mainly dedicated to the study of the solar corona and the solar wind. This tool is in charge of taking some spectacular images which de pict two comets that crashed on the Sun in 1997. Soho has also helped to develop a completely new science, helioseismology, which, like terrestrial seismology, ofers an indirect method to obtain information on our star’s internal structure and dynamics.

The vast legacy of expertise and knowledge developed in the manufacturing of the Uvcs is at the core of the design of Metis, the frst multi-band space corona graph mounted aboard the Esa Solar Orbiter mission. Metis is capable of obtaining simultaneous coronal images, both in the visible and in the ultraviolet light, and particularly in the Lyman-α line, emitted by the

hydrogen atoms. This spectral line, the most intense line of the external corona, is extremely important because it allows to use the diagnostic techniques de veloped by the Uvcs team to measure the speed of the solar wind.

Besides the Uvcs, Soho includes 11 complementary to ols, developed and provided by 12 international con sortia which involve 29 institutes from 15 countries, including Italy. Nine consortia are guided by Eu ropean scientists, the remaining three by U.S. scientists. More than 1500 scientists from countries all over the world are di rectly involved in the tools of the mission and have used data in their research programs.

Photo Esa-Nasa.credits: SPAZIO 2050 | WWW.ASI.IT33

The tool that has produced the most specta cular results is defnitely the Extreme Ultravio let Imaging Telescope (Eit). The telescope is capable of recording detailed images of the whole solar sur face in the ultraviolet light: in this way, it’s possible to detect solar fares, violent material eruptions which infuence the solar atmosphere.

In particular, the degradation of the satellite posi tioning services based on the signals emitted by the Global Navigation Satellite System (Gnss) and the disturbances to the HF-band radio communication

SpacEarth Technology was born in 2014 as a spin-of company of the National Institute of Geophysics and Vulcanology (Ingv), the largest European scientifc institute in the sector of geophysics, located in Rome. Today, it’s an innovative small and medium-sized en terprise, capable of turning sophisticated scientifc analyses into high added value commercial products.

by Silvia Ciccarelli

Follow Spacearth technology ’s page in the Italian Space Industry Online Catalogue, with updated contents and a link to the company’s offcial channels.

Spacearth technology

Therefore, an interdisciplinary team made up of re searchers, engineers, physicists, geologists and com mercial profles is working to mitigate the efects of such phenomena and develop customized solutions for diferent ground-based markets, by turning a hi ghly scientifc activity into a commercial product. A key role has been played by building a wide network of industrial relationships, not only on a national scale, by a privileged relationship with the world of science and, last but not least, by the essential support recei ved from institutions, including the Asi. All this has allowed to conduct the necessary activities to enhan ce the degree of technological maturity of products, a key step to increase their commercial potential.

The products made by SpacEarth have a strong in ternational projection; in fact, there’s an ongoing relationship with the Asian markets, including Vie tnam, and Latin American countries, also because the impacts of solar variability are higher for specifc latitudes. Exactly how ground-based weather fore casts have become common use services, due to the increasingly higher pervasiveness in the use of space-derived data in the feld of terrestrial economy, space weather will be destined to become a strategic domain also for the future commercial developments.

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tSpacearthechnology

MEDSZOOMONMALLANDIUMSIZEDENTERPRISES

In its 8 years of life, it followed a path aimed at de tecting and patenting innovative solutions, capable of generating a high impact on markets such as preci sion agriculture, air and sea navigation, over-the-ho rizon (Oth) telecommunications, control of the sta bility of structures and mitigation of natural risks, including those deriving from the solar activity. Spa cEarth operates in two main felds: monitoring of infrastructures and space weather. The latter is the discipline which deals with monitoring and predi cting the changes in the interplanetary space caused by the solar variability. Such phenomena may lead to operational abnormalities, decreased performance, disturbances for ground-based applications based on the use of space-derived data or even damages to the in-orbit equipment.

–fromCommerCialsolutionssCienCe

The algorithm developed and patented by SpacEarth is capable of predicting a few minutes early the occur rence of the so-called ionospheric scintillations, that is the stochastic fuctuations induced by the presen ce of the irregularities of ionospheric plasma on the Gnss signals received at ground level, and allows to maintain a level of centimetric accuracy also in such Stillconditions.onthe topic of ionospheric monitoring, SpacEar th manufactures and develops the Ais (Advanced Io nospheric Sounder), a radar operating in the HF-band which is capable of measuring the main ionospheric parameters (such as the height of the diferent layers and their respective densities) and, through its own specifc “Autoscala” software, automatically derives the local electronic density profle in real time.

ROME

A showcase for small and medium-sized enterpri ses and national start-up companies, whose goal is highlighting unique growth paths, evolving business models and adaptation and anticipation strategies of the most advanced New Space trends, so that the whole sector can drawfrominspirationthem.

(3-30 MHz) induced by the presence of the terrestrial ionosphere have turned out to be critical in diferent felds which are more and more frequently applied. Therefore, the ability to monitor and predict the iono spheric adverse events becomes extremely important to develop adequate countermeasures.

SZOOMULLEPMI

The Italian contribution to the next solar physics mission

Earth travels in the solar plasma, which, to all efects, is the most tenuous and external layer of the Sun’s atmosphere. Fed by the solar wind, its fow of parti cles can trigger dangerous geomagnetic storms, with important impacts on our planet, satellites and com munication systems. Particles are ejected by the co rona, the most external part of the solar atmosphere.

by Giuseppe Nucera

Understanding this region’s physical processes will be the goal of two future solar physics missions: the frst one is the Nasa Multi-slit Solar Explorer (Muse); the second one is the Jaxa Solar-C (Euvst). For both missions, Italy has proposed itself with an

One of the Sun’s biggest enigmas is the problem of co ronal heating. The solar corona, made up of low-den sity plasma, has a temperature of one million degrees Celsius; the lowest layer, the photosphere, has a tem perature of about 5600 °C, whereas the chromosphere, the middle layer, has a temperature of about 10000 °C. It’s a counterintuitive phenomenon, according to whi ch the temperature increases the further away we get

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important scientifc and technological contribution. In fact, the Italian skills play a key role on diferent fronts of such missions’ innovation, from the approa ch to the equipment.

Sun: it’s a matter of physics

This image of the Sun’s magnetic feld, taken thanks to computer models by the scientists of the Nasa Solar Dynamic Observatory (SDO), clearly shows concentrationthe of lines which make up the Sun’s magnetic feld, whose activities infuence the Sun’s DynamicsGSFC/SolarCredits:dynamism.Nasa/ Observatory

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«This technique allows us to obtain a spectral bidi mensional information, but with smaller timescales than those of the Sun’s intrinsic dynamism: this means that we’re able to freeze the solar atmosphere’s evolu tion processes and have a very high spectral resolu tion, but across large felds of view», says Stangalini.

to study the physical processes underlying the Sun’s dynamism, we move towards missions with a mix of performance: a high-resolu tion investigation for details; a high space coverage to observe large-scale areas; a broad-spectrum covera ge to investigate in more wavelengths; fnally, a high timing for observations, in a matter of few seconds. A complex recipe, implemented by technology un derlying Muse and Solar-C, the slit-grating spectro graph: a scanner capable of combining a broad visual feld with a fne space sampling, by providing simulta neous information across a wide spectral range.

An alternative technique is the spectral imaging, used by the Esa/Nasa Solar Orbiter mission. In this case, we use flters that are set only on a small portion of the bright spectrum: the 3D photograph of the solar at

will have to observe with very high timings. In fact, these releases happen in a matter of few seconds in the most external layers of the atmo sphere. However, the energy is stored by the magnetic feld across the whole atmospheric depth. From here comes the need for a 3D mapping of all the altitudes of the solar atmosphere.

by doing so we must move the opening each time du ring the investigation stage, to cover broader areas. It takes some time to complete this movement, and the re is the risk to miss a few moments of the observed phenomenon. The solution adopted by Muse is a grid of 37 slits, which simultaneously scan 37 sections of the solar surface and are subsequently stitched together, like a puzzle. Each slit will provide information on the diferent levels of the observed region, like a scanner which is capable of analyzing the ink, quality of paper and type of tabletop for each sheet of solar atmosphere.

«The magnetic structures can take up several thou sand kilometers, whereas the release of energy hap pens on small scale. This is why we simultaneously need a large scale-sight and a detailed look», says MuseStangalini.andSolar-C

It looks like the energy that heats the gas is coming from the Sun’s magnetic feld, made up of diferent li nes which act as rubber bands. In the photosphere, the gas of the plasma wraps such rubber bands, charging them with energy. When a line of the feld breaks due to the excessive accumulation, it releases energy in the plasma: therefore, the solar atmosphere becomes Anunstable.interweave between circumscribed events, the release of energy, and large-scale phenomena in the magnetic felds and solar plasma, with a mutual in fuence.

A small opening allows to investigate a section of the Sun’s atmosphere in diferent wavelengths. However,

«It is not enough to observe where the release of ener gy happens: in order to predict whether there are any areas of the feld which will start a release, we must understand the energy storage process by following it over time and across all the spatial scales of interest», says Therefore,Stangalini.inorder

from the solar surface. «In the frst 500 kilometers, we observe a decrease in temperatures, but then we immediately observe a sudden increase – says Marco Stangalini, researcher in Solar Physics and program manager of the Solar-C and Solar Orbiter mission at the Asi -; in a few hundred kilometers, the plasma swi tches from a few thousand to over one million degrees Celsius. We suspect that signifcant plasma energiza tion processes happen in this thin transition region».

The magneticSun’s feld, made up of diffe rent lines which act as rubber bands.

fc community, thanks to its multidisciplinary skills. «The smaller the wavelength is, the more light is suf fering from the asperities and roughness of the optics. Like a small wheel on a rough road, which, unlike the wheel of a tractor, perceives every perturbation.», says Furthermore,Stangalini.

«These solutions are the result of the skills acquired by Italy in several felds of the astrophysics. As well as requiring very extreme realization capacities, they can positively afect the performance of the whole tool», says Stangalini.

Following the investigation stage, we need the contri bution of modeling. In fact, after detecting each wa velength, the latter must be associated to its original atmospheric altitude; to do so, and to interpret what we observe in images, we must use complex realistic models of the solar atmosphere. Also in this feld, the Italian scientifc community participates with an important contribution to the Muse and Solar-C missions.

The Proba-3Esa Expectedtivedemonstramission. to start in 2023, it technologyfeld-testwilla to theincreasecorona and magne tic feld’s in vestigation region.

A depth capacity which implies the availability of mir rors and their respective flters, characterized by a perfect sanding, with a very small intrinsic roughness. This is to limit the perturbations that any superfcial asperities may cause in the observation of light with such small spectral lines. Also in this case, the solution to Muse and Solar-C is provided by the Italian scienti

«Each community has diferent background and expertise and the Asi has the task of putting these transversal skills together, to create innovation and open a new way of solar physics», concludes Stanga lini.

«Each wavelength of the solar radiation is formed at diferent altitudes of the solar atmosphere. Therefore, to explore diferent spectral ranges means to move to diferent solar altitudes: by observing simultaneously in the infrared and in the ultraviolet, we are investi gating a phenomenon along the diferent atmospheric altitudes. This is why we tend to increase the spectral coverage of solar physics missions», says Stangalini.

the interweave of skills has enabled the national scientifc community to propose innovative technological solutions for Muse, such as the special types of flters, mirrors or coatings, that is the levels deposited on optics to increase their performance.

The Italian expertise in the feld of solar physics will be also aboard the Esa Proba-3 demonstrative mis sion. Expected to start in 2023, it will feld-test a tech nology to increase the corona and magnetic feld’s in vestigation region. Italy will provide four sensors and, along with the Asi, is the third contributor to the mis sion. Proba-3 is based on the formation fight of two satellites: the Aspiics coronagraph and its occulting disk, which is 150 meters away. Compared to the tra ditional coronagraphs, whose disk is one meter away, Proba-3 will reduce the occulted region from 3 to ap proximately 1 solar rays. The four sensors manufactu red by the INAF, the Shadow Position Sensors, will as sess whether the front disk is in a correct position, by monitoring its shadow on the coronagraph or whether lighting is unbalanced. An essential Italian technolo gy for tandem fights in future solar missions. Therefore, Italy is a protagonist of the evolution of so lar physics, with a strong contribution from the INAF, CNR and some Italian universities, such as Padua and Palermo. Lastly, the coordination role played by the Italian Space Agency is essential to connect the dife rent wealth of knowledge.

mosphere is obtained by overlapping several images, each of them obtained in just a wavelength. In the case of Solar-C, the slit is provided by the contribution of the Italian scientifc community, thanks to which the Japanese mission will be able to simultaneously inve stigate the Sun’s atmosphere at diferent altitudes.

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«The nature itself of the researches targeted at spa ce weather presents a degree of scientifc interdisci plinarity and a mutual enhancement between ope rational and scientifc aspects which can hardly be observed elsewhere», says Christina Plainaki, resear cher in Solar System Sciences at the Asi and project scientist for Aspis. «What will be implemented within Aspis will range from heliophysics, to the physics of plasmas, planetary sciences, stellar astrophysics and terrestrial aeronomy. It will ofer a landscape which will really be capable of providing stimuli to several diferent communities. Over the years, we’ve been fo cusing – through Aspis – on such scientifc aspects», continues Plainaki.

«Today, researchers spend most of their time to re duce data, that is to treat such data based on the te chnology that has produced them, before being able to compare them with other data», explains Giusep pe Sindoni from the Asi, a project manager for Aspis.

Along with the monitoring of debris and Near Ear th Objects, space weather is one of the three pillars of safety in the space environment, of the activities conducted over there and of what depends on those activities on Earth, from navigation to telecommuni Thecations.science of space weather is characterized by a strong interdisciplinarity, where several scientifc sectors and subjects share their skills. In fact, the in terdisciplinary approach is essential to understand the nature of the phenomena which guide the Sun-E arth interaction and efectively face the issue of space weather prediction and the defnition of any counter Inmeasures.suchcontext, of diversifcation and opportunities at the same time, the partnership between the Asi and the Inaf led in 2021 to the Aspis (Asi Space Wea ther Infrastructure) tender, aimed at developing the prototype of a national data collection and proces sing centre for space weather. In Greek, Aspis means “shield” ( ίς); in fact, it’s the analysis and modelling of data which provide the necessary solid foundation to develop dedicated systems for the protection from

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ασπ

technological and biological impacts of space wea ther. The name of the winning proposal is Caesar, a project started in 2022 which involves over 80 scien tists from 11 universities and research bodies of all Italy. The two-year objective will be to populate the prototype of the single database, named Aspis, which will collect data provided by tools with the participa tion of Italy, as well as software and models developed by Italian researchers.

Aspis, A new prototype of scientific dAtA centre, tArgeted At the study of spAce we Ather by Giuseppe Nucera

The Italian scientifc community has been very acti ve for several years to study space weather, that is the infuence of the Sun’s activity on our planet and the other celestial bodies of the Solar System, and the re spective implications on the protection of our space assets.

Solar Sdo).(Credits:eruptionNasa/

«We believe that new and important partnership opportunities between the Asi, research bodies and universities will arise from the principle of the spre ad of skills and the meeting of diferent expertise within Aspis», adds Plainaki. «Aspis represents an important systematic efort to analyze the obtained data and the modelling related to space weather». Aspis wants to be a frst step towards the next pre diction tools which, in the future, can make an early estimate of the entity and evolution of solar particles fows, thanks to the monitoring of a few precursory signs. A frontier which will allow to develop adequa te protections for satellite technologies and radio protection for human exploration of space.

«We want to facilitate this stage of analysis, so that we can provide data which can be immediately used, in terpreted and compared, and maximize their scienti fc return», adds Sindoni.

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The main goal of Aspis will be to ensure a simple and efective access to multidisciplinary data on space weather and, at the same time, provide diferent kinds of information, such as images, spectra and fows, for diferent research topics. Therefore, we’ll be able to

have a multilevel look at solar phenomena, switching from chromosphere to the highly energetic events beyond the solar corona, until reaching the inte raction with celestial bodies like Earth.

«Each event has a cause which generates it, but it is not certain that cause and efect can be observed with the same tool or at the same time. Aspis will use several data and models to describe diferent stages of the same phenomenon», says Sindoni.

weatherofIdentikitthespace

The andconductiveionized,emitsconstantlySunafullyhighlyglobally neutral fow of gas, known as plasma, which is iselectronsprotonsmadeessentiallyupofandandcalledsolar wind (Sw).

In general, the Sun constantly emits a fully ionized, highly conductive and globally neutral fow of gas, known as plasma, which is essentially made up of protons and electrons and is called solar wind (Sw). The dy namics of the solar wind are described by Parker’s theory, formulated in 1957, according to which the coronal plasma is so warm that can escape solar gravity. In its motion, the solar wind drags behind the Sun’s magne tic feld and originates the interplanetary magnetic feld (Imf). Since the solar wind is emitted in all directions, its path, due to the solar rotation, is spiral-shaped and is known as Parker spiral. The phenomenon is simi lar to what happens to the irrigator of a garden, which sprays water by rotating on itself and let water follow a spiral-shaped path.

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«For now, it’s enough to have shown that spots are neither stars nor con sistent materials, and aren’t located far from the Sun but are produced around it, with a material which is not unlike that of clouds or other hazi ness around Earth». So reads Galileo Galilei’s frst letter to Mark Welser, duumvir of Augsburg and member of the Academy of the Lynxes, written in 1612. Galilei was the frst one to observe how our star, the Sun, wa sn’t a perfect and homogeneous sphere, but was covered with dark spots, which were later named solar spots. Today, we know that solar spots are the Sun’s magnetically active regions, and represent the main risk source of what are commonly named solar storms. Based on the theory which, still today, is the most accepted one, solar spots are generated by very intense magnetic fuxes, which get out of the solar surface once the fuxes themselves twist on top of each other due to the diferential rotation of the Sun’s magnetic feld. In fact, the Sun has an extremely weak magnetic feld with an unstable axis, which migrates from the poles to the equator, and then to the poles again, with an opposite orientation, in a period of approximately 22 years.

As well as the Sw, the Sun can impulsively emit from its active regions huge amounts of energy, both electromagnetic, such as solar fares, and particle energy, such as the coronal mass ejections, known as Cmes in the

Solar activity is measured based on the number of solar spots which can be found on the photosphere. The average number of solar spots is not steady, but varies between periods of maximum and minimum. The solar cycle is the period, lasting 11 years on average, between a period of mini mum – or maximum – of solar activity and the following one.

by Mirko Piersanti Researcher of the Department of Physics, University of L’Aquila

jargon. When one of such emissions hits Earth, it may lead, in particular conditions, to a geomagnetic storm. Earth owns an internal magnetic feld, the so-called geomagnetic feld, which on a frst approximation can be regarded as dipolar. As a matter of fact, the interaction with the solar wind changes its topology; by com pressing feld lines in the solar direction and extending them, it creates an actual tail in the anti-solar direction. This new confguration is called terrestrial magnetosphere.

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In general, the magnetosphere doesn’t allow the access to the particles carried by the solar wind. In fact, by behaving as a stone in a river, the magnetosphere acts as an obstacle against the solar wind which fows around its external surface, rather than reaching our planet’s atmosphe re or surface. This allows to have a stable planetary atmosphere over time, laying the foundations for the creation of complex biological life. However, during a Cme, the magnetospheric feld can be weakened, and can allow solar particles to reach the most external part of the terrestrial atmosphere, the ionosphere. The interaction between the latter and the particles carried by the Sw originates one of the most romantic and won derful phenomena on Earth: polar lights. These conditions develop when the magnetic feld carried by the solar wind has the same intensity and direction, but goes in the opposite way compared to the terrestrial one. Then, the two magnetic felds neutralize each other and cause the geo magnetic feld to decrease, generating the so-called geomagnetic storm. The timescales of a geomagnetic storm may range from a few hours to whole days, depending on the spatial scales of the solar perturbation. In general, what is observed on Earth is an initial depression of the geoma gnetic feld due to the increase in loop current, known as the main stage, and a subsequent and slow return to the pre-storm situation, known as the recovery stage, where the solar plasma is slowly ejected from the ge omagnetic tail. During the main stage, as well as the decrease of the feld, we can also observe at a high latitude the wonderful phenomena known as polar lights. They are caused by the reconnected magnetic fux in the sub-solar region, which is carried towards the geomagnetic tail by the plasma which fows in the magnetosphere’s polar regions, intensifying the feld of the geomagnetic tail. The latter discharges its energy throu gh the system of currents aligned with the feld, introduces plasma in the ionosphere, the auroral oval, and originates polar lights. During this process, very intense electric currents, known as auroral electrojet, are generated in the ionosphere. In general, the geographical position of the auroral oval is confned in the polar regions. However, the occurrence of a geomagnetic storm can cause the oval auroral to go down to lower latitudes, until reaching, in extreme cases, a latitude of 40°.

Lastly, the biological risk is strictly related to solar fares. These solar rays are numerous and energetic enough to cross the 2-3 millimeters of

The impact that these events may have on our society is mostly of tech nological nature, even if we can’t overlook some biological efects for the crews of fights with polar routes and for the astronauts on the Interna tional Space Station. In fact, the very intense ionospheric currents crea ted during a geomagnetic storm induce, in turn, very intense currents in the subsoil, the so-called Gics. Gics can interact with the national electric networks, causing blackouts which may also last a few hours. Further more, all satellite navigation and telecommunication services may sufer inconveniences, whose duration would range from several minutes to several house; this may cause delays/cancellations of fights and issues related with both road and sea transport. Finally, we can’t exclude the possibility of several orbiting satellites sufering transient anomalies or being permanently damaged.

by Mauro Messerotti Senior advisor for Space Weather, Inaf Scientifc Directorate Professor of Space Weather and Climatology, Department of Physics, University of Trieste

fares. Space is then irradiated by intense fashes of electromagnetic radiation (gamma, X-ray, extreme ultraviolet, radio) and is crossed by fows of accelera ted, high-energy fows of electrons and protons, the so-called Seps (Solar Energetic Particles), and huge bobbles of high temperature magnetized gas, the so-called Coronal Mass Ejections (Cmes). Such emis sions involve Earth and all the other planets of the So

Overall, the socioeconomic damage of a single extreme space weather event was estimated at up to 15 billion euros, only in Europe, in 2016, in the study contracted by the Esa. This means that accurate and timely spa ce weather services are very important to mitigate impacts and reduce the related socioeconomic costs. Because of this, the Esa will launch this year, along with the European Commission, a new study to analyze by 2024 the potential impact of space weather events on the European eco nomy and infrastructures and estimate the related socioeconomic costs. The Asi is also moving in this direction. On the one hand, it has created the Aspis (Asi Space Weather InfraStructure), which aims at developing a scientifc data centre which will host all the Italian models and databases related to the space weather. This is the frst Italian step towards future implementations of forecast models and services for space weather con ditions. On the other hand, the Asi is an integral part of the Cses (China Seismo-Electromagnetic Satellite) satellite mission. The Cses constella tion – the frst satellite has been fying since February 2018 and the se cond one is expected by mid-2023 – is in charge of monitoring the dyna mics of the electromagnetic feld, the plasma and the energetic particles in the ionosphere. The Asi is responsible for two of the nine payloads abo ard the satellites: the high-energy particle detector, in partnership with the Infn, and the electric feld detector, in partnership with the Inaf-Iaps.

Safety in space for technological systems and human beings requires a continuous activity to monitor and predict the phenomena which may endanger their integrity during space storms. The main source in our solar system is a star, the Sun. Solar activity is determined by the presence of sunspots in the Sun’s photosphere, which are unstable sources of concen trated magnetic energy, impulsively released in solar

These are the reasons why the science of the space weather, that is the science of space weather forecasts, was born in the last 30 years. It deals with trying to predict the arrival on Earth and the potential efects of a solar fare. At the moment, the best results in terms of lead-time range from 1 to 2 hours before, despite the fact that the solar event can be obser ved at least 2 days in advance.

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wall from the shuttle. Because of this, in case of a solar fare, the astro nauts on the Iss take shelter in an area where an artifcial magnetic feld is used to shield its efect.

Space weaTher, under Special Surveillance

The science of space weather forecasts try to predict the arrival on Earth and the potential effects of a solar ﬂare.

The Messerotti)(Credits:weathermonitoredsystemSun-EarthandthespacedomainsNasa,M.

mena. This kind of system is necessarily distributed among the diferent academic, industrial and military research contexts of a country.

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It is evident how the manufacturing of a system of this kind requires an infrastructure of observational as sets from Earth and space, a seamless collaboration in the feld of scientifc research and an infrastructure centre for space weather, which uses in a coordina ted manner all the available operational resources to conduct the short- (space weather) and medium-term (space climate) monitoring and prediction of pheno

Therefore, a cooperation agreement has been signed between the Italian Air Force, the Inaf and the Ingv, and will be extended to the Asi, for the implementation of the national monitoring and prediction system. The Inaf owns a network of ground-based assets for the solar and heliospheric weather, the Ingv is a reality of excellence for ionosphere weather, the Italian Air For ce ofers a space weather service for military purposes.

The Asi will signifcantly expand such skills thanks to its infrastructures and the experience acquired in the Ssa/Sst (Space Surveillance and Tracking) feld.

The European Space Agency has created a Space Si tuational Awareness (Ssa) system for space weather, to which several European countries, including Italy, contribute with specifc services. In the United States, the Noaa ( National Oceanic and Atmospheric Admini stration) manages the Space Weather Prediction Center in partnership with the Nasa and the Air Force (Usaf). Italy has started to develop a national space weather service, both for civil and military use. The kick-of has been given by the Italian Space Agency, which co ordinated the diferent Italian stakeholders, such as the Inaf, Ingv, Cnr, Infn, universities and industries, in a working table. The Inaf is currently working on the frst step of a scientifc data archive for space we ather at the Asi, named Aspis and known as Caesar (Comprehensive space wEather Studies for the ASPIS prototype Realization).

lar System, and cause malfunctioning of space vehi cles and the absorption of dangerous doses of ionizing radiations for astronauts but also for the cross-polar airline trafc on Earth, interfering in the propaga tion of radio waves in the terrestrial ionosphere and leading to interruptions of the distribution of electric energy.

In order to mitigate the harmful efects of space stor ms, it is therefore required to arrange a complex sy stem, based on the combined action of three comple mentary activities in the feld of space weather. The frst one is the continuous, real-time monitoring of sources and phenomena both from Earth and from space, since the terrestrial atmosphere blocks ra diations at diferent wavelengths. The second one is scientifc research, which provides the scientifc mo dels of such phenomena; fnally, we have prediction operations, based on scientifc models which are va lidated as operational – it can take several years of work for this process, represented by the close Rese arch-Operations-Research connection, known in the jargon as R2o2R – and are used by fnal users, be it the general public or satellite operators).

The space weather, this complex and relatively young subject, studies the infuence of the solar activity on the whole Solar System, as well as dea ling with the Sun – Earth relationships to prevent any inconveniences on our planet. The interstellar plasma, which can be found in the Milky Way and beyond, complicates the conditions of space weather, which is not determined only by our star.

The charged particles, magnetic felds and electromagnetic radiations emitted by the Sun occupy an area which includes all the planets orbiting around it, in a sort of bubble called heliosphere. We don’t know exactly how far it extends and what is its shape, but there are a few models gene rated by the work of space probes such as the Voyager 1 and 2, which have been travelling for 45 years: what is certain is the fact that, in turn, the heliosphere protects us from cosmic us. In fact, some phenomena with a very high energy level are generated in our galaxy, but also in external galaxies. Just think of the supernova emissions, the gamma-ray fashes or the powerful magnetic felds of the quasars.

44 | SPAZIO 2050 Polar light at Saturn’s North Pole – Cassini – Credits: Esa/Nasa Uranus’ rings and polar lights, flmed by Voyager 2 and Hubble – Credits: Nasa/Esa Hubble Jupiter’s polar lights – Chandra – Credits: Nasa

What’s the Weatherlike… in theSySolarStem?

The Sun is a source of life. A necessary, but also dangerous presence. An expression of nature, which implies the logic of a balance compensating for the strength of creation and destruction.

So, how do celestial bodies defend themselves within the heliosphere? The protective shields par excellence are the magnetic feld, the atmosphere and, sometimes, it’s the planet’s mass itself which shelters its satellites from the solar wind; the latter hits the surface of each planet, satellite, asteroid or comet, which reacts diferently based on its composition and distance from the Sun. For example, we encounter polar lights, the most fascinating expression produced by the solar wind, on almost all planets, even though with diferent manifestations.

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Let’s start with Mercury, the closest object to the Sun. It doesn’t have an atmosphere, but has a magnetic feld: the solar particles, which are ca nalized through it, hit its surface, extracting gas from the subsoil and creating auroras without lights and sound, in the polar areas. During the coronal mass ejections, instead, the magnetic feld is not efective, because its proximity to the Sun has eroded its outer crust over time, and the loss of volatiles substances will reduce it until it disappears. But because of this proximity, who better than Mercury can provide us with information on the infuence of our star? After the Nasa Mariner 10 and Messenger missions, now the European Space Agency (Esa) and Japanese Space Agency (Jaxa) Bepi Colombo probe is investigating the evolution of the planet. It was launched in 2018, it completed its second fy-by a few days ago and will enter Mercury’s orbit in 2025. Over a third of the tools of one of the two satellites aboard the shuttle are Italian: Serena ( Search for Exosphere Reflling and Emitted Neutral Abundances), Isa ( Italian Spring Accelerometer), Simbio-Sys (spectrometers and image recorders) and More ( Mercury Orbiter Radio science Experiment).

by Barbara Ranghelli

Then there is Venus, which doesn’t have a magnetic feld, but has a very dense atmosphere which protects the surface from solar particles and, subsequently, from erosion, but doesn’t protect it from overheating. The interaction between the solar wind and the atmosphere creates very complex dynamics, which are object of study. Earth, instead, has an intense magnetic feld, which can’t be outdone by coronal mass ejections either; the geometrical confguration of the ma gnetosphere allows the solar feld to collide with the atmosphere and re lease energy in the form of visible light; this phenomenon gives rise to polar lights with diferent frequencies, which create extraordinary lights and, sometimes, also sounds. Therefore, Earth would be capable of miti gating the efects of the solar activity, since it has been able to fnd a kind of balance with our star. This balance has been threatened by man, who

We know less about Saturn, Uranus and Neptune due to their distance. However, the Nasa, Esa and Asi Voyager and Cassini-Huygens probes, and sometimes also the Hubble telescope, have detected on these far planets the presence of polar lights, each of them with peculiar characteristics, following the impact of a swarm of solar wind particles. We’ve observed how the space weather transforms the celestial bodies of the Solar System; each of them re acts based on its status, because of this it’s important to understand the origin of phenomena, such as miti gating their consequences or preventing them.

Beyond the asteroid belt, and subsequently on the outer planets, the gaseous ones, the interaction with the solar wind is more complex. As well as the den se atmospheres, also satellites come into play; along with the Sun, they participate in the dynamics of their

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Heliosphere beensinceactivity,ofthemitigatingcapablebeofeffectsthesolarithasableto fnd a kind of star.withbalanceour

se activities have triggered a critical increase in the global average temperature on the planet’s surface. Mars, the fourth closest planet to the Sun, is helpless. It looks like it has lost its magnetic feld over time, and the Sun will gradually consume its atmosphere, whi ch is already rarefed. The solar wind will continue to take away material from the planet, advancing its erosion process.

mother planet, and vice versa. For example, the Italian Jiram ( Jovian Infrared Auroral Mapper) spectrometer, mounted on the Nasa Juno probe, has discovered that Jupiter’s polar lights aren’t originated by the solar plasma, but by the particles ejected by the volcanic activity of Io, one of the four largest moons of the pla net, visible from Earth.

and Solar –BepiobservedMercurySystem.asbyColomboSecondfyby –Credits: Esa/Jaxa. wouldearth

Last February, the Esa announced the name of a futu re mission which is entirely devoted to space weather forecasts: Vigil. These are two shuttles, whose launch isn’t expected before 2025, which will be placed in the Lagrange 1 and 5 gravitational balance points. Me anwhile, to make news about Mercury, the “messen ger of gods”, more usable, Bepit has been set up. It’s the pseudonym chosen by a group of researchers, which is in charge of the scientifc dissemination of the Italian tools aboard the Bepi Colombo mission.

The fact that our life depends on the Sun is old news. Without our star, there wouldn’t be any form of life on the whole Earth planet. However, the Sun wasn’t a key point for space exploration, at least not at the beginning of the space adventure. Just a few probes, mainly from the U.S., studied its physics and dyna mics between 1959 and 1968. Scientists were curious also back then, but their curiosity clashed with the te chnical difculty of developing missions which could get closer and closer to the Sun to collect further data. Compared to then, things have defnitely improved today, particularly from a technological standpoint. In fact, for slightly over 30 years, our star has been placed at the centre of the scientifc interest of every space agency in the world. Paolo Ferri, a graduate in Theoretical Physics at the University of Pavia, who’s been working for as many as 37 years at the control centre of the European Space Agency in Darmstadt, Germany, tells us the story of how we explored and how we are exploring the Sun.

Since the beginning, Ferri took part in the huge scien tifc and technological efort to send increasingly sophisticated space probes for increasingly ambitious missions. Starting from Ulysses, released in 1990 from the Space Shuttle, Soho, launched in 1995, and Cluster, a constellation of 4 satellites launched in 2000, and then daring to get closer and closer to the Sun, with Venus Express, launched in 2005 towards Venus, frst, then with BepiColombo, aimed at studying the planet Mercury, where it will arrive in 2025, and lastly with the Solar Orbiter, the most ambitious mission ever conceived to closely study our star. From 2006 to 2013, he was in charge of the mission operations of solar and planetary probes, whereas from 2013 to 2020 he was responsible for all the Esa robotic space missions. All these adventures, that he lived as a protagonist, are mentioned in the book, but what transpires is a strong humility in narrating them. This is a book that could have only been written by him, where Ferri nar

by Paolo D’Angelo

rates, as well as his career, how he faced the techno logical and human challenges and the thousand dif fculties he encountered. A couple of them stand over the other: giving a trajectory to the Ulysses probe to take it to Jupiter frst, and then, using a gravitational assist, catapulting it towards the Sun’s poles. A notbad-at-all pool game. Likewise curious is the story of his disappointment when he saw the European Ariane 5 carrier rocket exploding during its opening fight in 1996, with the four Cluster probes, designed to study the Sun, aboard. A strong disappointment, but also a lot of determination to make the program revive, with the initial manufacturing of just a new probe due to economic issues, and then the joy to see the willingness by several scientists and politicians to manufacture three more probes, in order to redesign the project as it had originally been conceived. Such probes were then successfully launched in June 2000 from Baikonur, with a Russian Soyuz carrier rocket. A very good book, conceived for a wide audience, which however lacks the index of names: we would have liked the individual projects or persons mentioned throu ghout the volume to be listed in alphabetical order in the fnal pages. Anyway, this is defnitely a venial sin, given the type of work. DISPLAY

how we explored and how we are exploring the most important star for our survival

The book theUnravelingdarksideofthesUn

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title: Il lato oscuro del Sole –nostraspazialeL’esplorazionedellastella author: Paolo Ferri house:Publishing Editori Laterza Year of edition: 2022 Price: 20 euros ON