Hubble 25th

iteractive poster series for Hubble Space Telescope 25th Anniversary

EXOPLA N ETS 01

///////////////////////////////////////// An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun, a stellar remnant, or a brown dwarf. More than 1900 exoplanets have been discovered (1909 planets in 1205 planetary systems including 480 multiple planetary systems as of 9 April 2015).

There are also rogue planets, which do not orbit any star and which tend to be considered separately, especially if they are gas giants, in which case they are often counted, like WISE 0855−0714, as sub-brown dwarfs.

SOLAR SYSTEM 02

///////////////////////////////////////// The Solar System formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system’s mass is in the Sun, with most of the remaining mass contained in Jupiter.

The four smaller inner planets, Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, the giant planets, are substantially more massive than the terrestrials. The two largest, the gas giants Jupiter and Saturn, are composed mainly of hydrogen and helium; the two outermost planets, the ice giants Uranus and Neptune, are composed largely of substances with relatively high melting points compared with hydrogen and helium, called ices, such as water, ammonia and methane. All planets have almost circular orbits that lie within a nearly flat disc called the ecliptic.

GR A VIT Y 03

///////////////////////////////////////// Gravity (or gravitation) is a natural phenomenon by which all things attract one another including stars, planets, galaxies and even light and sub-atomic particles. Gravity is responsible for the formation of the universe (eg creating spheres of hydrogen, igniting them under pressure to form stars and grouping them in to galaxies). Gravity is a cause of time dilation (time lapses more slowly in strong gravitation). Without gravity, the universe would be without thermal energy and comprise only of equally spaced particles.

GR AV. LEN S 04

///////////////////////////////////////// A gravitational lens refers to a distribution of matter (such as a cluster of galaxies) between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer. This effect is known as gravitational lensing and is one of the predictions of Albert Einstein’s general theory of relativity.

RED SHI FT 05

///////////////////////////////////////// A gravitational lens refers to a distribution of matter (such as a cluster of galaxies) between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer. This effect is known as gravitational lensing and is one of the predictions of Albert Einstein’s general theory of relativity.

BLACK H OLE 06

///////////////////////////////////////// A black hole is a mathematically defined region of spacetime exhibiting such a strong gravitational pull that no particle or electromagnetic radiation can escape from it.[1] The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2] The boundary of the region from which no escape is possible is called the event horizon.

Although crossing the event horizon has enormous effect on the fate of the object crossing it, it appears to have no locally detectable features. In many ways a black hole acts like an ideal black body, as it reflects no light.[3] [4] Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe.

DARK M AT TE R 07

///////////////////////////////////////// Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the largescale structure of the universe. It has not been detected directly, making it one of the greatest mysteries in modern astrophysics.

DEEP SPA CE 08

///////////////////////////////////////// The Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, composited from Hubble Space Telescope data accumulated over a period from September 24, 2003, through to January 16, 2004. Looking back approximately 13 billion years (between 400 and 800 million years after the Big Bang) it will be used to search for galaxies that existed at that time.

The HUDF image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. The image contains an estimated 10,000 galaxies. In August and September 2009, the Hubble’s Deep Field was expanded using the infrared channel of the recently attached Wide Field Camera 3 (WFC3). When combined with existing HUDF data, astronomers were able to identify a new list of potentially very distant galaxies.

BIG BA NG 09

///////////////////////////////////////// The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution. It states that the universe was in a very high density state and then expanded. If the known laws of physics are extrapolated beyond where they are valid there is a singularity. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later simple atoms. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies.

NEUTRO N STAR 10

///////////////////////////////////////// A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star after a supernova. Neutron stars are the densest and smallest stars known to exist in the universe; with a radius of only about 12–13 km (7 mi), they can have a mass of about two times that of the Sun. Neutron stars are composed almost entirely of neutrons, which are subatomic particles without net electrical charge and with slightly larger mass than protons. Neutron stars are very hot and are supported against further collapse by quantum degeneracy pressure due to the phenomenon described by the Pauli exclusion principle, which states that no two neutrons (or any other fermionic particles) can occupy the same place and quantum state simultaneously.

SUPER N OVA 11

///////////////////////////////////////// A supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months. The extremely luminous burst of radiation expels much or all of a star’s material at a velocity of up to 30,000 km/s (10% of the speed of light), driving a shock wave into the surrounding interstellar medium.

This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. A great proportion of primary cosmic rays comes from supernovae.

PUL SAR 12

///////////////////////////////////////// A pulsar (short for pulsating radio star) is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. This radiation can only be observed when the beam of emission is pointing toward the Earth, much the way a lighthouse can only be seen when the light is pointed in the direction of an observer, and is responsible for the pulsed appearance of emission. Neutron stars are very dense, and have short, regular rotational periods. This produces a very precise interval between pulses that range from roughly milliseconds to seconds for an individual pulsar.

The precise periods of pulsars make them useful tools. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered around a pulsar, PSR B1257+12. Certain types of pulsars rival atomic clocks in their accuracy in keeping time.

TIT AN 13

///////////////////////////////////////// Titan (or Saturn VI) is the largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere,[9] and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.[10] Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan’s diameter is 50% larger than Earth’s natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter’s moon Ganymede, and is larger by volume than the smallest planet, Mercury, although only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens,[11][12] Titan was the first known moon of Saturn, and the fifth known satellite of another planet.

TWIN GALA XIE S 14

///////////////////////////////////////// Titan (or Saturn VI) is the largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere,[9] and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.[10] Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan’s diameter is 50% larger than Earth’s natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter’s moon Ganymede, and is larger by volume than the smallest planet, Mercury, although only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens,[11][12] Titan was the first known moon of Saturn, and the fifth known satellite of another planet.

PILARS OF CREATION 15

///////////////////////////////////////// Titan (or Saturn VI) is the largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere,[9] and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.[10] Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan’s diameter is 50% larger than Earth’s natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter’s moon Ganymede, and is larger by volume than the smallest planet, Mercury, although only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens,[11][12] Titan was the first known moon of Saturn, and the fifth known satellite of another planet.

The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990, and remains in operation. With a 2.4-meter (7.9 ft) mirror, Hubble’s four main instruments observe in the near ultraviolet, visible, and near infrared spectra. The telescope is named after the astronomer Edwin Hubble.

Hubble’s orbit outside the distortion of Earth’s atmosphere allows it to take extremely high-resolution images with negligible background light. Hubble has recorded some of the most detailed visible-light images ever, allowing a deep view into space and time. Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.

designed by Almassy Daniel D

2015