MAC September 2011 Magazine by MAC Realta

Midlands Astronomy Club Magazine

Sky Guide - Beginner’s targets for September We'll start our September tour of the heavens overhead in the constellations Andromeda and Cassiopea. M31 (the Andromeda Galaxy), to locate M31, find the "W" of the Constellation Cassiopea. The larger part of the base of the "W" points right at the Andromeda Galaxy. Simply follow this line approximately a fist's width and slightly toward the horizon and scan this area with your lowest power eyepiece. You will see a bright blob in the middle with light extending off of both sides. I've been told that on a very good night, from a dark site, Andromeda will fill the field of view of your eyepiece. The Andromeda Galaxy is the most distant object that can be viewed with the naked eye at about 2.2 million light years away, which makes this a very easy first galaxy target for your scope. T he A nd r om e d a G a l a x y is considered the Milky Way's twin and is a member of a group of galaxies known as the local group. It's made up of about 300 billion stars and is considerably larger than the Milky Way. M31 is a spiral galaxy, but as we are seeing it edge on no spiral structure can be detected. Within the same low power eyepiece view, you may also detect M32 which is an elliptical galaxy. M32 is a very small smudge just below Andromeda (in the telescope view). It appears to be more of a fuzzy star than a galaxy through most beginners instruments but it's still another distant galaxy composed of millions of stars. M32 is located approximately 20,000 lightyears South of Andromeda. It is an elliptical galaxy. Moving over to Cassiopea, M103 is our next target. To locate M103 find the star that makes up the bottom of the smaller part of the "W" of Cassiopea (Ruchbah), M103 is located right next to this star in a straight line from it toward the star that makes the end of the "W" (Epsilon Cygni). M103 is a very

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Issue 26- September, 2011

loose open cluster of about 60 stars. Next, we'll use Ruchbah again, but with the other side of the "W" to find NGC's 869 and 884 (commonly referred to as the Perseus DoubleCluser). Follow this line down approximately a fist's width, and using your lowest power eyepiece, you will be treated to one of the most beautiful sights in the heavens. NGC 869 and 884 are a pair of Open Clusters each containing approximately 100 stars. It is located a a very rich area of stars which only adds to the beauty of this target. The sight is indeed a memorable one, and one I'm sure you'll return to often to show your friends. Planets in September Mercury is visible in the first half of the month as a morning object. At the start of the month, it rises at 04:50. Venus and Saturn are not visible this month. Mars moves from Gemini into Cancer during the month and is a morning object. It rises at 01:35 at the start of the month and at 01:20 by month’s end. It brightens from mag +1.4 to mag +1.3 during the month and passes through M44 – The Beehive Cluster on the morning of October 1st. Jupiter is an evening object this month. It can be found in Aries and rises at 21:50 at the start of the month and at 19:55 by month’s end. It brightens from mag -2.7 to mag -2.8 during the month. Uranus is an evening object this month and can be found in Pisces. At the start of the month, it rises at 20:50 and by month’s end, it rises during daylight hours.

month’s end. You’ll see very little detail, it will appear like a faint bluish star. Enjoy the September skies, this is one of the best months for observing, not too cold, no bugs, and gorgeous sights to be had in just about every area of the sky.

Cassiopeia is easily recognizable due to its distinctive 'W' shape formed by five bright stars. In the sky Cassiopeia sits with Andromeda on the South side and opposite The Big Dipper. In Greek mythology it was considered to represent the vain queen Cassiopeia, who boasted about her unrivalled beauty.

Club Notes Club Observing: Remember the next club meets every first Friday of the month (or second Friday if weather is bad), for our observing sessions held in the MAC grounds. If you wish to be informed of these sessions please email your name and mobile number to midlandsastronomy@gmail.com who will confirm if the session is going ahead (depending on weather).

MAC is a proud member of Neptune is an evening object and can be found in Aquarius. It rises during daylight hours during the month and maintains its brightness. It sets at 05:45 at the start of the month and at 03:45 by

Latest Astronomy and Space News Kids Astronomy Quizzes and Games Monthly Sky Guide Internet Highlights

Midlands Astronomy Club Magazine

Bucket List Object #6: The Transit of Venus ......................... 9

Kids Section Kids Korner ....................................................................... 10 Front cover image: The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars.

Credit & Copyright: The Hubble Heritage Team, (STScI/AURA), ESA, NASA

Quizzes and Games Exercise your brain ............................................................ 11

Monthly Sky Guide Beginners sky guide for April .............................................. 12

Internet Highlights Special content only available with the online version of the magazine ................................................................ 13

Big Bang Theory Impact Theory Hydroplate Theory Exploding Planet Theory 3. Luna, Artemis and Selene are amongst the many names given to the Moon by ancient cultures in their mythologies.

True False 4. A n c i e n t observers thought that the dark spots on the Moon were what?

Clouds Oceans Alien Cities Trees 5. The Moon rotates on its own axis.

True False

True False 9. The first manne d landing on the moon was in the area known as what?

Sea of Calmness Sea of Composure Sea of Serenity Sea of Tranquility 10.Evidence gathered in the “Clementine” mission suggests that there may be _________ in some deep craters near the Moon’s south pole.

alien spaceships lava new types of metal water ice

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4 5

Check your answers

the same face of the Moon.

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Answer 6: The correct answer was Lunar Eclipse. The shadow of the Earth is cast on to the Moon during an eclipse. This shadow is known as the "umbra". The "penumbra" is the area of broadening shadow.

The universe from your backyard ......................................... 8

8. The gravitational pull between the Earth and the Moon causes tides on Earth to rise.

Answer 7: The correct answer was Newton. This crater's wall rises 2.25 km above the Moon's surface. Its diameter is 113 km.

Impossible star is a cosmic mystery ...................................... 7

Aristotle Proclus Clavius Newton

Answer 1: The correct answer was Big Splat Theory. First, there was the "Coaccretion" theory, which said that the Moon and the Earth formed at the same time from the Solar Nebula. The "Fission" theory asserted that the Moon divided from the Earth. "Capture" theory, which stated that the Moon formed somewhere else and was later snared by the Earth's gravitational pull, was the last of these theories. All three of these didn't work very well.

The greatest mysteries of Jupiter's moons ............................ 6

7. What is the name of the deepest crater in the Moon?

Answer 8: The correct answer was True. The gravitational force of the Moon and the Sun on the Earth raises ocean tides. The Moon pulls up a bulge of water on the side of the Earth facing it. As the Earth rotates beneath this great bulge of water, high tides occur.

The Big Dipper .................................................................... 5

2. A f t e r the Apollo expeditions and the data that was gathered during them, scientists were able to put forward a more educated hypothesis regarding the Moon’s origin. What is the name of this theory?

Galactic Storm Solar Flare Lunar Eclipse Sun Spots

Answer 2: The correct answer was Impact Theory. In 1974, Hartmann and Davis stated that the Earth, in its primitive history, had a violent encounter with another planet and collided with one another which created the Moon.

You can see more about the club and its events on www.midlandsastronomy.com or contact the club via e-mail at midlandsastronomy@gmail.com Meetings are informal and are aimed at a level to suit all ages.

New 'Goldilocks' Exoplanet could be the most Earth-Like we've yet seen .................................................... 4

Capture Theory Big Splat Theory Binary Accretion Fission Hypothesis

Answer 3: The correct answer is True. Each one of the names referred to the personified goddess of the moon.

Astronomers discover a dark alien world ............................... 4

SUDOKU

Answer 9: The correct answer was Sea of Tranquillity. The Apollo 11 mission landed on July 20th, 1969. in the area of the Moon known as "The Sea of Tranquillity".

Life on Mars? Fossil find shows it's possible........................... 3

6. What is the name of the astronomical phenomenon that occurs when the Moon passes through the shadow cast by the Earth?

Answer 4: This gave rise to the Latin name, mare, meaning "sea". The brighter regions of the Moon were believed to be land in the dark oceans.

Supernova erupts in Pinwheel Galaxy ................................... 3

1. There were three main theories regarding the moon's origin before the Apollo missions. Which one of the following is NOT one of those first three?

Answer 10: The correct answer was water ice. This information has now been confirmed by the "Lunar Prospector" mission. The discovery of ice on the Moon gives new light to the possibility of further exploration of space.

Latest Astronomy and Space News

All are welcome to attend. It also holds infrequent Observing Nights at its Observing Site in Clonminch, or at a member’s house (weather permitting) on the first Friday of every month..

Exercise your brain

contents

Answer 5: The Moon's rotation is in tune with its orbit, it rotates once with every orbit. This means that the Moon doesn't appear to rotate, but it does, making it possible for humans to see

MAC meets on the first Tuesday of the month in the Presbyterian Hall, High Street, Tullamore from 8pm.

Midlands Astronomy Club Magazine

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Midlands Astronomy Club Magazine

Kid’s Korner Build a Bubble Powered Rocket! Build your own rocket using paper and fizzing tablets! Watch it lift off. How high does your rocket go? Print this page for the instructions.

one right way to make a paper rocket. Try a long, skinny rocket or a short, fat rocket. Try a sharp nosecone or a blunt nosecone. Try it with fins or without fins. Experiment!

• Eye protection (like eye glass- Here's just one idea for how you es, sun glasses, or safety glasses)

might cut your whole rocket from one piece of paper:

Hints: Suggestion: Find a grown-up to do Right kind of film canister - The this activity with you. film canister MUST be one with a cap that fits INSIDE the rim instead Materials: of over the outside of the rim. Sometimes photography shops • Paper, regular 8-1/2have extras of these and will be by 11-inch paper, happy to donate some for such a such as computer worthy cause. printer paper or even notebook paper. • Plastic 35-mm film canister (see Keep in mind: Just like with real rockets, the less your rocket hints below) weighs and the less air resistance • Cellophane tape (drag) it has, the higher it will go. • Scissors

Here are the basic steps: Young rocket engineer

• Effervescing (fizzing) antacid Making the Rocket: • •

tablet (the kind used to settle an You must first decide how to cut your paper. You may cut it the upset stomach) short way or the long way to make Paper towels the body of the rocket. There is no Water

1. Cut out all the pieces for your rocket. 2. Wrap and tape a tube of paper around the film canister. Hint: Tape the canister to the end of the paper before you start wrapping. Important! Place the lid end of the canister down. 3. Tape fins to your rocket body, if you want. 4. Roll the circle (with a wedge cut out) into a cone and tape it to the rocket's top.

Blasting Off 1. Put on your eye protection. 2. Turn the rocket upside down and remove the canister's lid. 3. Fill the canister one-third full of water. Now work quickly on the next steps! 4. D r o p o n e - h a l f o f a n effervescing antacid tablet into the canister. 5. Snap the lid on tight. 6. Stand your rocket on a launch platform, such as your sidewalk or driveway. 7. Stand back and wait. Your rocket will blast off!

Supernova erupts in Pinwheel Galaxy Good news for those of you who missed out on June's supernova in the Whirlpool Galaxy, M51: You can slew just across to the other side of the Big Dipper's handle to track another stellar explosion. This one's located in the face-on spiral M101, the Pinwheel Galaxy. It was discovered on August 24th at magnitude 17.2 by the Palomar Transient Factory (PTF), an automated supernova search being conducted with the 1.2-m Oschin Schmidt Telescope at Palomar Observatory in southern California. Since the same telescope saw nothing at the same location one day earlier (limiting magnitude = 20.6), the stellar explosion must have been caught mere hours after its onset. According to PTF participant Andy Howell (University of California, Santa Barbara), never before has a Type Ia supernova been discovered so early in its brightening. "As soon as I saw the discovery image I knew we were onto something big," he says.

Above: A finished rocket ready for lift-off.

Designated SN 2011fe (though dubbed "PTF 11kly" initially), the

supernova is brightening rapidly. It had already climbed to 13.8 by 20h Universal Time on August 25th, as noted by Krisztián Sárneczky at Konkoly Observatory in Hungary. Spectra taken earlier that day at Lick Observatory show broad, blueshifted absorption lines from ionized calcium and silicon blasting outward at 14,500 to 16,500 km per second — and no hydrogen lines. These are characteristics of a Type Ia supernova: the complete thermonuclear destruction of a carbon-oxygen white dwarf star that had been collecting mass in a binary system. The supernova was up to magnitude 13.8 on the evening of the 25th and 12.4 on the evening of the 27th. S&T's Alan MacRobert estimated it at 11.5 on the evening of the 29th (August 30.1 UT) using a 12.5-inch scope at 75× and an AAVSO comparison-star chart. On

Life on Mars? Fossil find shows it's possible

Above: An image showing the supernova in the pinwheel galaxy getting brighter over a period of time. the evening of September 2nd he put it at 10.7, in line with AAVSO visual estimates. The early detection, combined with the relative closeness of M101 (23 million light-years), makes this a spectacular find for professional researchers. A normal Type Ia supernova at this distance should reach magnitude 10.0 at its peak, if none of its light is absorbed by interstellar matter in M101. That's well within visual reach in a 4-inch telescope — and much brighter than the galaxy appears visually! In a light-polluted sky you'll be using the supernova to find the galaxy rather than vice versa.

"We can be very sure about the age as the rocks were formed between two volcanic successions that narrow the possible age down to a few tens of millions of years," he said. "That's very accurate indeed when the rocks are 3.4 billion years old."

Scientists have found Earth's oldest fossils in Australia and say their microscopic discovery is convincing evidence that cells and bacteria were able to thrive in an oxygen-free world more than By analysing the fossils, the rocks 3.4 billion years ago. The finding suggests early life was sulphur-based -- living off and metabolizing sulphur rather than oxygen for energy -- and supports the idea that similar life forms could exist on other planets where oxygen levels are low or nonexistent.

For a nosecone, use a jar lid or something like that to trace the circle required. Roll this long piece around the film canister for the rocket body Tape canister to the edge of paper before you start rolling paper around canister. www.midlandsastronomy.com Page - 10

http://www.marcsobservatory.com/default.html

"Could these sorts of things exist on M a r s ? I t' s j us t a b o ut conceivable. This evidence is certainly encouraging and lack of oxygen on Mars is not a problem," said Martin Brasier of Oxford University, who worked on the

team that made the discovery. The microfossils, which the researchers say are very clearly preserved and show precise cell-like structures, were found in a remote part of western Australia called Strelley Pool. In a study published in the journal Nature Geoscience on Sunday, Brasier's team explained that the tiny fossils were preserved between the quartz sand grains of the oldest shoreline known on Earth in some of the oldest sedimentary rocks ever discovered.

they were found in and the surrounding environment, the scientists have built a picture of Earth at this time as a hot, murky, violent place where there was a high and constant threat of volcanic eruptions and meteor strikes. The sky would have been cloudy and grey, keeping the heat in even though the sun would have been weaker than today, and the oceans would have been around 40-50 degrees Celsius -- the temperature of a hot bath.

If you haven't yet tracked down this fleeting fireball, do it soon. The Dipper's handle is getting lower after dark, and moonlight will return to the evening sky by about September 3rd or 4th. Relatively bright at 8th magnitude but large and diffuse, the Pinwheel Galaxy sits north of the last two stars in the Big Dipper's handle, forming a roughly equilateral triangle with them 6° on a side. The supernova is located about 4.4 arcminutes south (and a bit west) of M101's centre. www.skyandtelescope.com

were no plants or algae to photosynthesize and produce it, Brasier explained in a telephone interview. "It's a rather hellish picture," he said. "Not a great place for the likes of us. But for bacteria, all of this was wonderful. In fact, if you were to invent a place where you wanted life to emerge, the early Earth is exactly right." The researchers are now using the techniques and approaches they used in this study to re-examine other fossil finds that scientists have suggested may also contain evidence for very early life on Earth. www.reuters.com

Most significantly, there was very little oxygen around since there

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Midlands Astronomy Club Magazine

Astronomers discover a dark alien world An exoplanet has been discovered by astronomers that reflects less than one percent of the light it receives from its parent star. Less reflective than black acrylic paint, this planet is literally darker than coal! TrES-2b is a Jupiter-sized gas giant orbiting the star GSC 03549-02811, about 750 light-years away in the direction of the constellation Draco. First discovered in 2006 by the Trans-Atlantic Exoplanet Survey (TrES), its unusual darkness has been identified by researchers led by David Kipping from the HarvardSmithsonian Centre for Astrophysics (CfA) and David Spiegel from Princeton University, using data from NASA’s Kepler spacecraft. The team monitored the brightness of the TrES-2 system as the planet orbited its star and detected a

subtle dimming and brightening due to the planet’s changing phase. A more reflective planet w ould ha ve s how n la rg er brightness variations as its phase changed. The dark exoplanet is tidally locked with its star and orbits it at a distance of only 5 million kilometres (3.1 million miles), keeping it heated to a scorching 1000º C (1,832º F). Too hot for the kinds of reflective ammonia clouds seen on Jupiter, TrES-2b is wrapped in an atmosphere containing light-

New 'Goldilocks' Exoplanet could be the most Earth-Like we've yet seen

Midlands Astronomy Club Magazine

a b s o r b i n g che mic als like vaporized sodium and potassium, or gaseous titanium oxide. Still, this d o e s n o t completely explain its extremely dark appearance. “It’s not clear what is responsible for making this planet so extraordinarily dark,” stated coauthor David Spiegel of Princeton University. “However, it’s not completely pitch black. It’s so hot that it emits a faint red glow, much like a burning ember or the coils on an electric stove.” Regardless of its faint glow TrES-2b is still much darker than any planet or moon in our solar system.

Of the hundreds of exoplanets a s tr onom er s ha ve r ec e ntly discovered orbiting distant stars,

Above: Needs More Clouds - A rendering of what an alien habitable planet might look like if we could ever get close enough to see it.

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Over the next several months, we present our totally subjective list of ten celestial sights to see before you die, or “kick the bucket”, as they say. We call it the “Bucket List for Backyard Stargazers”. Our list is targeted at the casual stargazer, with no special expertise or training or ambition other than to see some of the most beautiful, and in some cases, transient sights in nature. For some of these objects, you’ll need access to a pair of binoculars or a small telescope. Others require travel and good timing and luck. And for others, you need to simply look up. But all these sights are not that hard to see, once you know how and when and where to look for them. We’ll help you with that. Above: The exoplanet TrES-2b (artist's concept) is darker than the blackest coal, with an albedo (reflectivity) of less than 1%. Astronomers don't know what dusts or vapours in its superheated atmosphere cloak it so effectively. (The two moons are the artist's added touch. There is no evidence, yet, for any satellite of an exoplanet.)

www.universetoday.com

only one--Gliese 581d--has been of the proper mass and distance from its star to be considered a strong candidate for habitability. Nearby Gliese 581g was once thought to be even more Earth-like than 581d, until some scientists asserted that 581g doesn’t even exist--a point that is still under debate.

Scientists have tracked down another goldilocks planet 31 lightyears from Earth, and according to astronomers it has some strong points in its favour when it comes to the possibility of harbouring the ingredients for life. HD85512b is just the right distance from the sun--and just the right mass--to rank among HD85512b was discovered by the the most Earth-like planets ever discovered. ESO’s High Accuracy Radial velocity And by “among,” we mean really one of just two (or three, depending on how you feel about Gliese 581g).

Bucket List Object #6: The Transit of Venus

Planet Searcher, or HARPS, in Chile (it’s the same instrument that found Gliese 581d. The data show that HD85512b is roughly threeand-a-half times the mass of Earth and rings its planet on the inner fringe of the so-called “goldilocks zone” that is not to distant and not too close to harbour liquid water. It’s size is also indicative of an Earth-like atmosphere of oxygen and nitrogen rather than the hydrogen and helium that dominate the atmospheres of larger worlds. That alone makes it a potential candidate for life, but HD85512b has a couple of other characteristics working for it. For one, its orbit is almost perfectly circular and stable, so any climate on the planet wouldn’t swing wildly as it orbits. The planetary system is older than our own--a full one billion years older--so clearly it’s

had enough time for life to potentially have developed there. in the same vein, its star is also more mature than our sun so it is less prone to violent solar activity that could destabilize the planet’s atmosphere. Of course, there’s no way to tell if it actually has an atmosphere with modern instruments, and atmosphere is a critical ingredient here. Since HD85512b is orbiting on the inner portion of the goldilocks zone, it is more akin to Venus than to Earth in the amount of solar energy it’s taking on. But scientists speculate that cloud cover of fifty percent or more could offset that proximity enough to allow life to thrive--albeit a kind of life more suited to a balmy, hot environment (relative to Earth’s). On average, Earth boasts 60 percent cloud cover so the idea of HD85512b having 50 percent isn’t so far-fetched. In fact, it’s probably more likely than the idea of humans building a light-speed spacecraft and then making the 31-year journey to go in for a closer look at the weather. But it’s fun to think about. www.popsci.com

During the transit, the black disk of Venus, just 33x smaller than the solar disk, blocks enough light to measurably decrease the Sun's brightness. NASA's Kepler observatory, in fact, uses this same idea… a transiting planet blocking light from its home star… to look for Left: Earth-like planets around nearby The stars. Astronomers will use the 2012 b" lack transit of Venus to test new drop measurement techniques to find effect" visible extra-solar planets such as those during used by Kepler. the 2004 The 2012 transit begins at 22:09 UT transit (GMT) on June 5, and ends at 04:50 UT on June 6. The western Pacific, including most of Australia and New Zealand can see the entire transit. Western Africa, Spain and Portugal, and eastern South America will not see the transit because it occurs when the sun is set. And the rest of the world can see some of the transit after the Sun rises or before it sets.

Now to #6… the passage of Venus across the solar disk as seen from the Earth, also called the transit of Venus. While not as striking as a solar eclipse, a transit of Venus is far more rare. It's happened just seven times since the invention of the telescope more than 400 years ago. The next transit in June 2012 will be our last chance to see this remarkable event. There won't be another until December 2117. Like a solar eclipse, a transit occurs when Venus passes between Earth and the Sun. And like an eclipse, the transit requires careful alignment of the Sun, Earth, and Venus. As seen from Earth, Venus usually passed over or under the Sun every 584 days, on average. But the geometry of the orbits of Earth and Venus, and the period of the planets' orbits cause Venus to pass in front of the Sun at welldefined intervals of 121.5 and 101.5 years, in either June or December. And the transits occur in pairs separated by eight years. Right now, we're between transits. The last occurred on June 8, 2004. The next is on June 6, 2012. The last transits came on December of 1874 and December 1882.

which bleeds darkness from the limb of the planet as it moves onto the solar disk. The same two stages reverse themselves as the planet leaves the solar disk. The whole event takes 3-6 hours, compared to the scant few minutes of a solar eclipse.

The transit of 1769 was measured precisely by, among others, the team led by one Lieutenant James Cook, RN. Astronomers used Cook's measurements to calculate a distance to the Earth of 150 million kilometres, close to the now-accepted value of 149,597,870.7 kilometres.

It's the history, and the rarity of the event, that makes the transit of Venus such a compelling sight. And it's a beautiful sight, too, even for the casual stargazer. The transit unfolds in four stages. First, the leading edge of the planet contacts the Sun. Then the trailing edge, which is hard to time exactly because of the “black drop effect”

The maps below shows where the 2012 transit of Venus is visible. To see the transit, you'll need a safe solar filter. It's visible without a telescope, but you'll get a better view if you watch the event with a scope and a solar filter. So start planning. After June 6, 2012, you won't get another chance to see this rare and beautiful event… www.oneminuteastronomer.com

A transit of Venus was once a huge deal for astronomers. In the early 18th century, Edmond Halley determined a way to measure the distance from the Earth to the Sun by timing the transit of Venus from widely separated parts of the Earth. Once this distance was known, the distances to other planets could be determined through Kepler's Laws. The transits were so important that most advanced nations sent astronomers around to world to measure the events of 1761 and 1769.

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Midlands Astronomy Club Magazine

The universe from your backyard

Midlands Astronomy Club Magazine

seen on Discovery Channel – but you will see a tiny glowing sphere with up to 4 tiny dots strung out in a line, perhaps two on one side and two on the other or even three on one side and one or none on the other.

The Big Dipper The Big Dipper is perhaps the most famous and easy to find star group in the northern skies. While it’s not a constellation itself, the Big Dipper makes up the brightest section of the large and sprawling constellation Ursa Major, the Great Bear. There’s much to see for stargazers in and around the Big Dipper. Let’s take a look…

When we look upward on a starry night we naturally see stars and on occasion we see our moon – but how many of us consider our place in the cosmos whilst in our own backyard These tiny spots are some (astronomically speaking of course). It would surprise many to know that each of those pin-points of light we call stars are in fact other suns, like our own sun but mind-bogglingly far away. So far away that the words like miles and kilometres do not help and astronomers instead refer to their relative distances in light years (the distance light will travel in a solar year) or approximately 10 trillion kilometres in a year. There are a few pin-points of light over our heads that are not in fact stars – but planets. They are our neighbours and are visible to the unaided eye on a dark and cloudless night. Two of these in particular always attract my attention, Jupiter king of the solar system and Saturn, sometimes referred to as the jewel of the solar system. Although Mars, Venus and Mercury are also visible, it’s the first two mentioned that steal the show. Of course I only fail

to mention Uranus and Neptune because being so far away they are a little more difficult to spot without the aid of a telescope As an amateur astronomer living in the midlands and one of the greatest pleasures is sharing this wonder with others. To this end, I and other members of Midlands Astronomy Club organise observing sessions on occasion. We bring our telescopes to villages and schools to share with members of the community the wonder an awe of the cosmos. I am always a little taken back by the response from those who for the first time in their lives put their eye to the telescope and see Saturn for the first time – when they see the rings of Saturn with their subtle shading or the gaps between them or the shadow of the rings cast upon its surface. “Wow” is often a word uttered in a quiet and breathless whisper… or a profanity brought about by sudden surprise.

of Jupiter’s moons (like a solar system within a solar system) they orbit Jupiter with the same precision that our own moon orbits the earth. Jupiter is of course so massive that it could easily accommodate all the other planets of the solar system put together. Mighty Jupiter can be resolved in greater detail in a modest back garden telescope. By the way (note to self) must buy sky atlas… or download one free from Interweby thingy and wipe dust from binoculars.

Yes, the solar system is truly a wonderful treasure chest, and like the anxious enquiry of lord Carnarvon, when he asked Howard Carter whether he could see anything through the small hole he had made in the wall of Tutankhamen’s tomb… ”Wonderful

things” were the only words he could utter. That’s what it is sometimes like to peer through the hole in my telescope eyepiece – and metaphorically and astronomically we haven’t even left the garden yet.

Declan Molloy is the Chairman of the Midlands Astronomy Club (MAC) having been a member for many years. Declan is also enjoys painting and sketching and has painted a number of astronomical objects. www.midlandsastronomy.com

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one of Ptolemy’s original 48 constellations from the 2nd century A.D. The bear’s head is marked by the star Muscida, the forepaws by Talitha, and the rear paws by Tania Borealis and Tania Australis.

Greek, Hebrew, and some native American cultures all see this constellation as a bear. According to Iroquois legend, the bowl of the Big Dipper is a giant bear and the stars of the handle are three warriors chasing it. As the constellation is low in the autumn evening sky, legend explains the hunters had injured the bear and its blood turned the leaves of the The Big Dipper, or the “Plough” as trees to red. it’s called in Great Britain, makes up the body and tail of Ursa Major,

Ursa Major is circumpolar for much of the northern hemisphere, which means it never sets below the horizon. But it’s highest in the sky in the evening hours from March through early July. In the southern hemisphere, at least from South Africa and Australia, you can just glimpse the star Alkaid in the tip of the handle of the Dipper in late May on the northern horizon. From southern parts of New Zealand, alas, the Dipper is never seen.

Above: The Plough, also known as the Big Dipper, is an asterism of seven stars that has been recognized as a distinct grouping in many cultures. The component stars are the seven brightest of the formal constellation Ursa Major. The Big Dipper is an excellent base of operations for finding other stars in the northern hemisphere. Draw an imaginary line from Merak through Dubhe out of the cup of the dipper and continue through 5x their separation to find Polaris, the North Star. Or draw an imaginary arc along the handle of the Dipper and extend the arc around the sky. This leads you to the very bright star Arcturus in the constellation Boötes. Continue to reach Spica in Virgo. Remember: “Arc to Arcturus and Speed on to Spica.”

Well who can blame them? I had the same response the first time I looked through a telescope from my own back garden many years ago, and hey, it’s only a mere billion kilometres away. No matter how many images we see on television or on magazines, nothing compares with that first time you see this marvel for the first time. With a modest pair of binoculars, (yes that’s right, I said binoculars, that little case hanging under the coats in the hall) anyone can step out into their garden - weather permitting and spot Jupiter. Now, to be honest, it won’t be a great ball of hydrogen gas with cloud banding and a great red spot as

The stars of the Big Dipper include, from handle-tip to bowl: Alkaid, Mizar, Alioth, Megrez, Phad, Dubhe, and Merak (see image below). The dipper shape is a coincidence, but most of these stars (save for Alkaid and Dubhe), along with a few others, are moving together through space to a point in the constellation Sagittarius. The stars form a “moving group”, a loose association of stars once part of a star cluster but no longer gravitationally bound to one another. This so-called Ursa Major Moving Group is also recorded in Per Collinder’s list of star groups as Collinder 285.

Greek legend holds the bear is the poor Callisto, a beautiful nymph who caught the eye of Zeus. His wife Hera turned Callisto into a bear and sent her into the forest. Thinking she was a fea rs ome be as t, Callisto’s son Arcas almost killed her. To prevent this tragedy, Zeus cast them both into the sky.

Or follow the other two stars in the cup of the dipper, Megrez and Phecda, down below the cup to get to Regulus, the brightest star in Leo.

Above: As the image above shows, there is a pair of binoculars for every level of interest, from beginner to advanced user. Regardless of experience most astronomers have a pair of binoculars which are very handy for a quick view of the night sky.

For advanced stargazers, Ursa Major is awash in galaxies. We’ve met the superb pair M81 and M82 before. Other Messier objects include the harder-to-find Owl Nebula (M97) and the Pinwheel Galaxy (M101). Dozens more fainter galaxies await the experienced stargazer with a bigger telescope… www.oneminuteastronomer.com

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Midlands Astronomy Club Magazine

Midlands Astronomy Club Magazine deflected by a magnetic field. "How that [magnetosphere] gets created is very fascinating," said Bolton. "We don’t know of another small body that has that."

The greatest mysteries of Jupiter's moons The biggest planet in the solar system, Jupiter, also boasts the most moons, with 64 currently catalogued. Most of these moons are tiny, lumpy rocks — apparently asteroids captured by Jupiter's gravity — and they swarm about the giant planet like so many bees around a hive.

tug-of-war between Jupiter and the other three Galilean moons with Io caught in the middle. The constant stretching and compressing that this tug exerts on Io heats its interior, prompting the moon to often ooze out lava and spew sulphur and ash into space.

Four of Jupiter's moons, however, are quite substantial — so much so that they can be seen through a rudimentary telescope. The inventor of just that instrument, Italian astronomer Galileo Galilei, first saw the thusly named "Galilean moons" in 1610: Io, Europa, Ganymede and Callisto.

Such tidal forces, however, might not account for all this oomph. The history of variances in the gravitational flexing of Io also remains murky.

Together, these four moons comprise more than 99.9 percent of the mass of Jupiter's satellites. Each of them has a distinctive character, and they all present vexing scientific puzzles. Here is a rundown of the top mysteries regarding Jupiter's primary four moons. Io, the hyperactive pizza moon

Ganymede's magnetosphere is most likely made in a manner much like Earth's, due to convection in the moon's liquid iron core. Learning how it's generated would help with better understanding our own planet's magnetic field. To boot, Ganymede might also a Above: The Galilean moons of Jupiter. From left, they are Io, Europa, Ganymede, and Callisto. This composite includes the hidden ocean sloshing under its four largest moons of Jupiter which are known as the Galilean satellites. The Galilean satellites were first seen by the Italian astronomer Galileo Galilei in 1610. Shown from left to right in order of increasing distance from Jupiter, Io is closest, grey, rocky and icy crust. followed by Europa, Ganymede, and Callisto. Battered Callisto

"I don’t think we know enough about the exact frequency of these things to adequately assess the whole mechanism," said Scott Bolton, principal investigator for NASA's Juno spacecraft mission, which launches Friday (Aug. 5) to study Jupiter. Given how interesting the moon is, "Io could be the focus of an entire mission," added Bolton, who, in addition to his Juno post, is also director of the space science and engineering division at the Southwest Research Institute in San Antonio, Texas. Europa, a smart bet for extraterrestrial life?

Above: This f"amily portrait,"a composite of the Jovian system, includes the edge of Jupiter with its Great Red Spot, and Jupiter's four largest moons, known as the Galilean satellites. From top to bottom, the moons shown are Io, Europa, Ganymede and Callisto.

even free up oxygen to power bigger life forms, such as fish. Ganymede, magnetic

big

and

oddly

perhaps 20 miles (three to 32 kilometres) thick, Europa probably harbours a saltwater ocean. Depending on the assumptions and models used, this ocean could have twice the volume of all those on Earth. Io is the closest of the Galilean moons to Jupiter. This proximity is thought to help explain the moon's uniquely hellish, sulphur-yellow, redsplotched and pockmarked appearance. Those pocks, in fact, are volcanoes. Io sports 400 or so active volcanoes, as well as soaring mountains formed by tectonics. Overall, the moon is the most geologically active object in our solar system. The energy powering this activity comes largely from a gravitational

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The moon of Jupiter that's definitely highest on the list for someday getting its own dedicated mission is Europa. This icy-white object with brownish streaks on its surface stands as one of the best candidates for hosting extraterrestrial life in our solar system. Under an icy crust anywhere from a couple to

Understandably, astronomers are bubbling over with questions about this subterranean (sub-Europian?) sea. The chief query: "Might it allow for life development in any way?" asked Bolton. The idea is not so far-fetched. Tidal flexing from Jupiter could keep the interior of Europa warm. This energy could, in turn, support microbial life analogous to that found around hydrothermal vents in Earth's oceans. Cosmic rays from space striking the crustal ice could

Jupiter's largest moon, Ganymede, reigns as the biggest moon in the solar system. In fact, it's even larger than the planet Mercury. Another distinction for Ganymede: it's the only moon with its own magnetosphere, which is a region surrounding the world where charged particles from the sun are

The Galilean moon with the farthest orbit from Jupiter is Callisto. Unlike Io and Europa (and even

Ganymede to an extent), where geologic activity has erased many craters, Callisto bears the scars of eons' worth of meteorite impacts. The geologically dead moon is considered the most heavily cratered object in the solar system.

as well, yet another possible abode for alien life out in Jupiter's neighbourhood.

Callisto's landscape is therefore among the oldest on record, aged some four billion years. Analysing its surface materials would be like opening a time warp back to the early solar system.

R ing ed rem nan ts of a destroyed moon Since its discovery in 2000, a tiny moon just 2.5 miles (four kilometres) in diameter and given the designation S/2000 J 11 has gone missing. Astronomers think the moonlet has actually smashed into Himalia, Jupiter's fifth most massive moon after the four Galileans.

Callisto might be full of surprises on the inside, too — an underground ocean could lurk here

That possible impact appears to have created a streak of material, observed in 2006, that might even

be a whole new ring around Jupiter. The planet's faint rings naturally do not get the fanfare of Saturn's resplendent rings, but as with Saturn, moons play a key role in supplying the particles that make up the giant disks. www.space.com

Impossible star is a cosmic mystery

and determine what chemicals it is made of from its spectrum.

Astronomers are mystified by a star they have discovered in the Milky Way – because theories say that it shouldn’t even exist. The star, which may be one of the oldest in the universe, is made up almost entirely of hydrogen and helium.

Also surprising to the team was the lack of lithium in the star. Because of its age, it was expected to contain 50 times more lithium than it does because that metal existed along with hydrogen and helium in the early Universe.

Other chemical elements that ought to be there are missing, according to observations using the Very Large Telescope (VLT) at the European Southern Observatory in Chile. That puts the star, dubbed SDSS J102915+172927 after its positional number in the Sloan Digital Sky Survey, in what accepted theory calls the “forbidden zone” meaning it should never have formed at all. The star, which is in the constellation of Leo, is smaller in size and is thought to be much older than the Sun – 13 billion years compared to the Sun’s 4.5 billion years. Astronomers call all elements heavier than helium

“metals”, even though they may not resemble what the rest of us mean by that term. The discovery team were surprised to find that the “impossible star” has incredibly small amounts of these metals – fewer than ever detected in a star before. This suggests to them that the star is extremely old because younger s tar s c onta in mor e hea vy elements, produced from the remains of supernova explosions spread throughout space. Chief discoverer Elisabetta Caffau, of Heidelberg University, Germany and the Paris Observatory, France, said: “A widely accepted theory

predicts that stars like this, with low mass and extremely low quantities of metals, shouldn’t exist because the clouds of material from which they formed could never have condensed. It was surprising to find, for the first time, a star in this ‘forbidden zone’, and it means we may have to revisit some of the star formation models.”

Dr Bonifacio said: “It is a mystery how the lithium that formed just after the beginning of the Universe was Colleague Piercarlo Bonifacio, of destroyed in this star.” Paris Observatory, said: “The star is faint, and so metal-poor that we The team, whose discovery is could only detect the signature of revealed in the journal Nature, say one element heavier than helium — that their “impossible star” is calcium — in our first observations. probably not unique. They have We had to ask for additional found candidates which appear to telescope time from ESO’s Director have similar, or even lower, levels of General to study the star’s light in metals and are preparing to observe even more detail, and with a long them with the VLT to check them exposure time, to try to find other out.

metals.” Two spectrographs on the VLT, called X-shooter and UVES, were used to analyse the star’s light

www.dailygalaxy.com

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