9+- EALTA The Midlands Publication of the Tullamore ... · PDF fileDeirdre Campbell helps out....

Réalta – Volume 7, Issue 2 – November/December 2005 – Tullamore Astronomical Society 1

Reviews, Events And Lectures – Tullamore Astronomy

Publication of the Tullamore Astronomical Society.

The Midlands only Astronomical Newsletter!Volume 7: Issue 2 – November/December 2005

Price: €5.25www.tullamoreastronomy.com

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REALTASpace: Imagination Knows No Frontiers


The competition finally came to a close on Saturday October 22nd. A presentation ceremony was organised, the music was playing, Big Bear made an appearance, and one end of the Byrne’s World of Wonder Tullamore store filled with eagerly awaiting kids and their families! Big Bear had lots of candy to give out, and with the festive atmosphere of a birthday party, and presents galore, the kids one by one came up and received their prize. The end to the TAS & Byrne’s Children’s Art Competition, had come to a climatic finale. There was a short recap by TAS’s Seanie Morris, and a welcome speech by Councillor Richard Egan, as emphasis was on the children and their imaginations in space and astronomy were highlighted and acknowledged. Back (l-r): Seanie Morris (TAS), Conor Rohan, Sean Hughes, John Cooke (Mngr, Byrne's WoW), Siobhain McCormack (judge), Big Bear (aka Earl Morris), Councillor Richard Egan, Shane Murray (Ast. Mngr, Byrne's WoW). Middle (l-r): Ciara O'Shea, Eanna Duffy, Conor Lynch, Jason Boland, Lucinda Daly, Shauna Stringer. Front (l-r): Heather Burke, Becky McDonagh, Colm McGuinness, Conor McGuinness. Picture by Darren Dempsey (TAS).

And then there were12 WinnersSpace: Imagination Knows No Frontiers

During the weeks leading up to the presentation, Michael O’Connelland Seanie Morris compiled the calendar. It now consists of the 12 winningposters accompanying each month, loaded with fun facts and historical datesand snippets. It also shows the key phases of the Moon throughout eachmonth, and includes notes on where to observe each of the planets.

The calendar is available to buy in Byrne’s World of Wonder, or atTAS meetings, priced €10. You can also obtain one by sending an SAE (96cents stamped) with €10 o the club secretary. All monies raised go into theclubs fund towards erecting a clubhouse next to the observatory. This will bea public accessible structure, which is hoped to be completed within 3 years.

Comes to a climatic close


Key organisers and folks involved in the running ofthe competition: (l-r) Councillor Richard Egan, ShaneMurray (Byrnes WoW), Siobhain McCormack (judgedthe entries), Michael O’Connell (TAS), Seanie Morris(TAS), John Cooke (Byrnes WoW), and Earl Morris(Byrne’s WoW). A very special thank you is extendedto them for giving their time and energy into thecompetition and calendar. (Photo by DarrenDempsey)

Many casual shoppers came in to have a look at whatwent on! Interest even went further than was hoped, as JohnFlannery (centre-right) from South Dublin Astronomy Society(SDAS) came down all the way from Ranelagh! Even thecompetition itself drew in entries from Offaly, Westmeath,Kildare Galway, and Laois counties! (Photo by DarrenDempsey)

Seanie Morris presented Shane Murray with a batch ofthe TAS 2006 Calendars a couple days after thepresentation. So far (at the time of print), it is on sale inByrne’s World of Wonder Tullamore and Mullingar shops.(Photo by Seanie Morris)

Seanie Morris after setting up his ETX-70 and the P.A.system – but was he overlooking them to make sure BigBear would not ‘steal’ the show?! Deirdre Campbell helpsout.

It was deemed that each winning entry was worthy of 1st

Place!

Becky McDonagh (7) from Tullamore, Ciara O’Shea (12) from Clonderig in Ballinahowen, Colm McGuinness (6) from Ballycue in Geashill, Conor Lynch (8) from Aughanrush in Killeigh, Conor McGuinness (5) from Ballycue in Geashill,Conor Rohan (11) from Ballinahowen, Eanna Duffy (9) from Ballinahowen, Heather Burke (8) from Tannery Wharf in Rathangan, Jason Boland (10) from

Ballinahowen, Lucinda Daly (10) from Ballinahowen, Sean Hughes (12) from Kearney Park in Tullamore, and Shauna Stringer (7) from Corolanty in Shinrone.

TAS says Congratulations to each of the winners, and a huge Well Done to over 330 more that entered!


Letters to the Editor From: Girvan McKay Hello again, Seanie. This has nothing to do with Maire's lecture title, but maybe readers of Réalta might be faintly interested to read the following enquiry and my reply, which I received from a correspondent re: constellation names. ORIGINAL ENQUIRY: ----- Original Message ----- From: "Sìol Cultural Enterprises" <[email protected]> To: <[email protected]> Sent: Monday, September 19, 2005 2:13 PM Subject: Inquiry to Gaelic Constellations Hi, I’m doing some research on Scottish Gaelic (and older Celtic) astronomical terms. In my searching on-line I ran across a listing of the constellations in numerous languages including Galeic and Irish (constellation-names.at). I believe you contributed the Scottish Gaelic names of constellations (and the Irish). I was wondering what your source for these names was. Thanks for your help. Cheers, Trueman Matheson, Sìol Cultural Enterprises, St. Andrew's, NS, CANADA http://www.gaelicbooks.com MY REPLY: Thanks for the enquiry. The sources for the constellation names were, respectively: Scots Gaelic: REUL-EOLAS - by Patrick Moore, translated by Iain Aonghas MacLeoid, published 1997 by John A. Macleod, Largs, Ayrshire, ISBN 0 9530874 0 9. Also: THE ILLUSTRATED GAELIC-ENGLISH DICTIONARY, Edward Dwelly, various editions and reprints. Irish Gaelic: FOCLOIR REALTEOLAIOCHTA/ Dictionary of Astronomy, (name of compiler not given), publisher AN GUM, Dublin, 1996, ISBN 1-85791-175-X. Also: ENGLISH-IRISH DICTIONARY, Tomas de Bhaldraithe, published by Government Publications, Dublin 1959. -Hope this helps. Girvan McKay / Garbhan MacAoidh. Thanks for that Girvan. It’s nice to get a query from across the waters! –Ed.

Club Snippets

TAS Christmas Party will be coming up soon. A date hasnot been fixed yet, so keep an eye on our website, or you willbe notified via e-mail. If you are not already on the TAS E-mailList to be kept up to date with club news and astronomy events,send an e-mail to [email protected]. Club Fleeces There are still a few left. Sizes available areLarge or Medium. Priced €15, they can be purchased at anymeeting.

TAS AGM This was fixed for Tuesday December6th, but due to some committee members not beingable to make it that night, it may be pushed up to thestart of the New Year. Members will be advised. Ifyou would like to become a more active member,then this will be your chance as a member to haveyour say in what the club should do. The AGM isopen to everyone.


From Around The Universe

Hubble Searches for Oxygen on the Moon

During the summer, scientists pointed the Hubble Space Telescope at the Moon to take a closer look at its soil. Initial findings support the potential existence of some unique varieties of oxygen–rich glassy soils in both the Aristarchus and Apollo 17 regions. They could be well suited for visits by robots and human explorers to learn how to live off the land on the Moon.

While Hubble wasn't specifically designed to look at the Moon (it only has the resolution of a football field for an object so close) scientists can use the ultraviolet capability of its Advanced Camera for Surveys to analyse the contents of lunar soil, particularly minerals and ore that might contain oxygen.

Since the Moon does not have a breathable atmosphere, and spacecrafts have limited load capacities, harvesting oxygen from the soil may be critical for long-term human missions. Hubble found that the soil in the regions examined contained abundant amounts of ilmenite, a mixture of titanium, iron, and oxygen.

Laboratory experiments on Earth have shown that applying certain chemical processes to terrestrial ilmenite can easily liberate oxygen and water. Water can then be turned into oxygen and hydrogen, which could also be used for rocket fuel.

Other studies have found evidence for water ice near the lunar poles. While those areas might serve well

for human outposts, they are not necessarily the first choices for science missions. The Hubble team examined three lunar sites, two of which – the Apollo 15 and 17 landing sites – where soil chemistry is well known. The third was the Aristarchus crater, a "geologic wonderland" that has piqued geologists' interest for decades. The Aristarchus crater is the brightest feature of the Moon's near side, nearly twice as bright as most spots on the Moon and visible to the naked eye. It's just 25 miles across but more than two miles deep. At only 450 million years old, it is one of the younger major features on the Moon.

More importantly, it sits in a region of the Moon that scientists believe was once rocked by volcanic explosions and tectonic shifts. The two-mile gouge exposes the historical record of what went on in the region, including the history of crust and mantle formation on a young satellite. Aristarchus crater was the planned landing site for Apollo 18, but no human or robot has ever set foot there, making it a likely target for the Lunar Reconnaissance Orbiter as it explores the lunar surface in 2008, according to current plans. Data from that mission, combined with Hubble's observations, will help plan the location of future robotic and human missions.

Craters in Planets and Moons Not What They Seemed

A hole in a moon or planet does not always mean what astronomers thought. Most of the craters on Jupiter's moon Europa are formed by chunks of rock and ice splashing back down onto the moon's surface after a meteor strike, a new study suggests. It was previously thought that most of the craters seen on moons and planets were the work of direct, or "primary" impacts from asteroids

and comets. The new finding suggests that most of those craters might instead be "secondaries," impacts that formed by the material ejected from primary impacts.

For Europa, secondaries account for as much as 95% of all the small craters - those less than a mile in diameter - observed on the moon. The finding has implications for how astronomers date the ages of planetary surfaces.

Asteroids, comets and chunks of cosmic debris routinely bombard the surface of planets and moons. Earth's atmosphere protects us from most of these impacts, incinerating most objects before they hit the ground. Even so, Earth has experienced countless meteor impacts throughout its long history. The evidence for most of those impacts have been erased by erosion from wind and rain and by constant turnover of the Earth's

NEWS UPDATE

New crater formation theory HST searches for oxygen on the Moon Russia to launch Brazils first astronaut 10th ‘planet’ has a moon Marswas once like Earth 2 new moons for Pluto Life’s building blocksabundant in space


crust (read the article about Apophis and a likely Earth impact in 2036 in the Sept/Oct 2005 issue of Réalta –Ed.).

Earth's Moon, on the other hand, is pockmarked with millions of craters because it lacks both atmosphere and geologic activity. Similarly, Mars has thin atmosphere and relatively little geologic activity.

On both the Moon and Mars, teasing out the primary impacts from the secondaries is difficult because the craters are just too numerous.

The researchers instead turned to Europa and a world covered in a thick crust of ice. More importantly, Europa is geologically active like Earth. Its surface is constantly being repaved with new ice and as a result, Europa has very few craters.

Using high-resolution images from NASA's Galileo

spacecraft, the researchers measured the number, size and distribution of craters on Europa. They then ran a computer simulation of meteors randomly striking Europa but with the condition that the number and size of the craters had to match the real number and size observed in the images. After running the simulations hundreds of times and comparing the results to the images, they found that the crater distributions were not similar as would be expected if most of the craters were caused by primary impacts.

The finding is important because scientists typically use crater counts to date the ages of planet and moon surfaces. When comparing two similar regions on a moon, for example, scientists generally assume that the region with more impact craters is older. Scientists can also use a region's

crater density to calculate it's absolute age. They usually use our own Moon as a reference because scientists have reliably dated the age of some its craters based on rocks brought back by astronauts.

If it turns out that most of these small caters are secondary and not primary, then that means the calibrated age from our Moon is not right.

Most of the objects that strike Jupiter and its moons come from a region of the Solar System known as the Kuiper Belt. Therefore, another implication of the finding may be that there are fewer small asteroids in the Kuiper Belt than previously thought. It may be that small asteroids are rarely made or perhaps some process depletes them before they can reach Jupiter and its moons.

Life's Building Blocks 'Abundant in Space'

The idea that comets and meteorites seeded an early Earth with the tools to make life has gained momentum from recent observations of some of these building blocks floating throughout the cosmos. Scientists scanning a galaxy 12 million light-years away with NASA's Spitzer Space Telescope detected copious amounts of nitrogen containing polycyclic aromatic hydrocarbons (PANHs), molecules critical to all known forms of life.

PANHs carry information for DNA and RNA and are an important component of haemoglobin, the molecule that transports oxygen through the body. They also make chlorophyll, the main molecule responsible for photosynthesis in plants, and perhaps most importantly, they're the main ingredient in caffeine and chocolate.

"There once was a time that the assumption was that the origin of life, everything from building simple compounds up to complex life, had to happen here on Earth," said study leader Doug Hudgins of Ames Research Center. "We've discovered that some very biologically interesting molecules can be formed outside our earthly environment and delivered here."

While organic compounds have been discovered in meteorites that have landed on Earth, this is the first direct evidence for the presence of complex, important biogenic compounds in space. So far evidence suggests that PANHs are formed in the winds of dying stars and spread all over interstellar space.

"This stuff contains the building blocks of life, and now we can say they're abundant in space," Hudgins said. "And wherever there's a planet out there, we know that these things are going to be raining down on it. It did here and it does elsewhere." Using the Spitzer Space Telescope, Hudgins and his colleagues detected the familiar chemical signature of regular polycyclic aromatic hydrocarbons (PAHs) in the spiral galaxy M81, as well as a similar, but unknown signature.

"There were a few anomalies in the spectrum that we couldn't explain," Hudgins says. The researchers compared their readings to the infrared signatures of similar molecules, finally settling on nitrogen containing PANHs because their data showed there was nitrogen in the regions they were investigating.

"When we did that, we found that by putting a little nitrogen in these molecules explained the troubling molecules," Hudgins said. "This discovery takes this reservoir of molecules that we didn't think were interesting and transforms all this stuff into something of biologic interest."


Moon discovered orbiting Solar System's 10th planet

The newly discovered 10th planet, 2003 UB313, is looking more and more like one of the Solar System's major players. It has the heft of a real planet (latest estimates put it at about 20 percent larger than Pluto), a catchy code name (Xena, after the TV warrior princess), and a Guinness Book-ish record of its own (at about 97 astronomical units-or 9 billion miles from the sun, it is the Solar System's farthest detected object). And, astronomers from the California Institute of Technology and their colleagues have now discovered, it has a moon.

The discovery of the moon of the 10th planet from the W.M. Keck Observatory. The planet appears in the centre, while the moon is the small dot at the 3 o'clock position.

The moon, 100 times fainter than Xena and orbiting the planet once every couple of weeks, was spotted on September 10, 2005, with the 10-meter Keck II telescope at the W.M. Keck Observatory in Hawaii by Michael E. Brown, professor of planetary astronomy, and his colleagues at Caltech, the Keck Observatory, Yale University, and the Gemini Observatory in Hawaii.

"Since the day we discovered Xena, the big question has been whether or not it has a moon," says Brown. "Having a moon is just inherently cool-and it is something that most self-respecting planets have, so it is good to see that this one does too."

Brown estimates that the moon, nicknamed "Gabrielle"-after the fictional Xena's fictional sidekick-is at least one-tenth of the size of Xena, which is thought to be about 2700 km in diameter (Pluto is 2274 km), and may be around 250 km across.

To know Gabrielle's size more precisely, the researchers need to know the moon's composition, which has not yet been determined. Most objects in the Kuiper Belt, the massive swath of miniplanets that stretches from beyond Neptune out into the distant fringes of the solar system, are about half rock and half water ice. Since a half-rock, half-ice surface reflects a fairly predictable amount of sunlight, a general estimate of the size of an object with that composition can be made. Very icy objects, however, reflect a lot more light, and so will appear brighter-and thus bigger-than similarly sized rocky objects.

Further observations of the moon with the Hubble Space Telescope, planned for November and December, will allow Brown and his colleagues to pin down Gabrielle's exact orbit around Xena. With that

data, they will be able to calculate Xena's mass, using a formula first devised some 300 years ago by Isaac Newton.

"A combination of the distance of the moon from the planet and the speed it goes around the planet tells you very precisely what the mass of the planet is," explains Brown. "If the planet is very massive, the moon will go around very fast; if it is less massive, the moon will travel more slowly. It is the only way we could ever measure the mass of Xena-because it has a moon."

The researchers discovered Gabrielle using Keck II's recently commissioned Laser Guide Star Adaptive Optics system. Adaptive optics is a technique that removes the blurring of atmospheric turbulence, creating images as sharp as would be obtained from space-based telescopes. The new laser guide star system allows researchers to create an artificial "star" by bouncing a laser beam off a layer of the atmosphere about 75 miles above the ground. Bright stars located near the object of interest are used as the reference point for the adaptive optics corrections. Since no bright stars are naturally found near Xena, adaptive optics imaging would have been impossible without the laser system.

"With Laser Guide Star Adaptive Optics, observers not only get more resolution, but the light from distant objects is concentrated over a much smaller area of the sky, making faint detections possible," says Marcos van Dam, adaptive optics scientist at the W.M. Keck Observatory, and second author on the new paper.

The new system also allowed Brown and his colleagues to observe a small moon in January around 2003 EL61, code-named "Santa," another large new Kuiper Belt object. No moon was spotted around 2005 FY9-or "Easterbunny"-the third of the three big Kuiper Belt objects recently discovered by Brown and his colleagues using the 48-inch Samuel Oschin Telescope at Palomar Observatory. But the presence of moons around three of the Kuiper Belt's four largest objects-Xena, Santa, and Pluto-challenges conventional ideas about how worlds in this region of the solar system acquire satellites.

Previously, researchers believed that Kuiper Belt objects obtained moons through a process called gravitational capture, in which two formerly separate objects moved too close to one another and become entrapped in each other's gravitational embrace. This was thought to be true of the Kuiper Belt's small denizens-but not, however, of Pluto. Pluto's massive, closely orbiting moon, Charon, broke off the planet billions of years ago, after it was smashed by another Kuiper Belt object. Xena's and Santa's moons appear best explained by a similar origin.

"Pluto once seemed a unique oddball at the fringe of the solar system," Brown says. "But we now see that Xena, Pluto, and the others are part of a diverse family of large objects with similar characteristics, histories, and even moons, which together will teach us much more about the solar system than any single oddball ever would."


Russia Agrees to Launch Brazil's First Astronaut to ISS

Brazil’s first astronaut will launch toward the International Space Station (ISS) in March 2006 under an agreement with Russia’s Federal Space Agency. Lt. Col. Marcus Pontes, of the Brazilian Air Force, is slated to ride up to the ISS aboard a Russian-built Soyuz spacecraft with the crew of Expedition 13 under an agreement signed between the Federal Space Agency and Brazilian Space Agency (Agéncia Espacial Brasileiria).

The Brazilian cosmonaut’s flight has been set for late March 2006 at the insistent request of

Brazil, which failed to launch its cosmonaut under a program of NASA. Pontes, 42, reported to NASA’s Johnson Space Center in Houston, Texas in 1998 to begin astronaut training. He served with the Space Station Operations Branch of NASA’s Astronaut Office while awaiting a spaceflight assignment, according to NASA officials.

In a statement posted to their space agency’s website, Brazilian space officials said Pontes will carry about 33 pounds (15 kilograms) of scientific equipment into orbit on his 10-day flight, and conduct a series of

experiments before returning to Earth with the Expedition 12 crew. He has already reported to Russia’s Star City for cosmonaut training and will spend eight days aboard the ISS, they added.

Expedition 12 commander Bill McArthur and flight engineer Valery Tokarev boarded the ISS on Oct. 3rd and are expected to spend at least six months in space before returning to Earth aboard their Soyuz TMA-7 spacecraft in early April

New map provides more evidence Mars once like Earth

NASA scientists have discovered additional evidence that Mars once underwent plate tectonics, slow movement of the planet's crust, like the present-day Earth. A new map of Mars' magnetic field made by the Mars Global Surveyor spacecraft reveals a world whose history was shaped by great crustal plates being pulled apart or smashed together.

Above: An artistic illustration of Earth magnetic field and Mars

magnetic field Scientists first found evidence of plate tectonics on Mars in 1999. Those initial observations, also done with the Mars Global Surveyor's magnetometer, covered only one region in the Southern Hemisphere. The data was taken while the spacecraft performed an aerobraking manoeuvre, and so came from differing heights above the crust.

This high resolution magnetic field map, the first of its kind, covers the entire surface of Mars. The new map is based on four years of data taken in a constant orbit. Each region on the surface has been sampled many times. The more measurements that are obtained, the more accuracy, and spatial resolution, can be achieved.

The map lends support to and expands on the 1999 results. Where the earlier data showed a "striping" of the magnetic field in one region, the new map finds striping elsewhere. More importantly, the new map shows evidence of features, transform faults, that are a "tell-tale" of plate tectonics on Earth. Each stripe represents a magnetic field pointed in one direction-positive or negative - and the alternating stripes

indicate a "flipping" of the direction of the magnetic field from one stripe to another.

Scientists see similar stripes in the crustal magnetic field on Earth. Stripes form whenever two plates are being pushed apart by molten rock coming up from the mantle, such as along the Mid-Atlantic Ridge. As the plate spreads and cools, it becomes magnetized in the direction of the Earth's strong global field. Since Earth's global field changes direction a few times every million years, on average, a flow that cools in one period will be magnetized in a different

direction than a later flow. As the new crust is pushed out and away from the ridge, stripes of alternating magnetic fields aligned with the ridge axis develop. Transform faults, identified by "shifts" in the magnetic pattern, occur only in association with spreading centres.

To see this characteristic magnetic imprint on Mars indicates that it, too, had regions where new crust came up from the mantle and spread out across the surface. And when you have new crust coming up, you need old crust plunging back down - the exact mechanism for plate tectonics.


Two New Moons for Pluto?

New images gathered by the Hubble Space Telescope have revealed that this distant planet could have two additional moons. If this is true, Pluto will be the first Kuiper Belt Object found to have multiple moons. The candidate moons have been provisionally named S/2005 P1 and S/2005 P2, and are approximately 44,000 km (27,000 miles) away from Pluto.

Using NASA's Hubble Space Telescope to probe the ninth planet in our Solar System, astronomers discovered that Pluto may have not one, but three

moons. If confirmed, the discovery of the two new moons could offer insights into the nature and evolution of the Pluto system, Kuiper Belt Objects with satellite systems, and the early Kuiper Belt. The Kuiper Belt is a vast region of icy, rocky bodies beyond Neptune's orbit.

Pluto was discovered in 1930. Charon, Pluto's only confirmed moon, was discovered by ground-based observers in 1978. The planet resides 3 billion miles from the sun in the heart of the Kuiper Belt. The candidate moons, provisionally designated S/2005 P1 and S/2005 P2, were

observed to be approximately 27,000 miles (44,000 kilometres) away from Pluto. The objects are roughly two to three times as far from Pluto as Charon. The team plans to make follow-up Hubble observations in February to confirm that the newly discovered objects are truly Pluto's moons. Only after confirmation will the International Astronomical Union consider names for S/2005 P1 and S/2005 P2.

The Hubble telescope's Advanced Camera for Surveys observed the two new candidate moons on May 15th. The new satellite candidates are roughly 5,000 times fainter than Pluto, but stood out in these Hubble images. Three days later, Hubble looked at Pluto again. The two objects were still there and appeared to be moving in orbit around Pluto. A re-examination of Hubble images taken on June 14, 2002 has essentially confirmed the presence of both P1 and P2 near the predicted locations based on the 2005 Hubble observations. The teams involved looked long and hard for other potential moons around Pluto. These Hubble images represent the most sensitive search yet for objects around Pluto, and it is unlikely that there are any other moons larger than about 10 miles across in the Pluto system.

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UP UPCOMING ASTRONOMICAL EVENTS

Compiled by John Flannery, South Dublin AS Summary Winter Solstice occurs on December 21st at 18:35hrs: Winter officially begins in the Northern Hemisphere. Eclipses No eclipses occur during this time. The Planets Binocular users may just about spot Mercury in the evening sky around time of greatest eastern elongation on November 3rd (24°) given a clear south-western horizon. Your best chance of seeing the planet falls during December in the morning sky. Mercury begins December about 5° above the south-eastern skyline at the beginning of civil twilight and climbs higher each day until greatest western elongation (21°) on the 12th when it can be found at an altitude of 9.5° around the same time of morning. Thereafter, it slowly retreats sunward (but remains quite bright at magnitude -0.4) and will probably be lost to view by New Year’s Day. A word of caution; if you are looking for Mercury in any sort of optical instrument make sure you do not accidentally sweep up the Sun in the field. It therefore makes sense to look for the planet in binoculars or a telescope after sunset or before sunrise. Advanced amateurs do observe the planet in daylight close to the Sun but only by taking careful precautions and having telescopes with setting circles that allow you to accurately “home in” on Mercury’s position in the sky. Venus has remained quite low in the evening sky all year but is now beginning to pull clear, gaining in altitude during the two-month period covered by these notes. It lies highest in our evening skies in mid-December (still only about 12 in altitude though) and reaches greatest brilliancy on December 9th (magnitude -4.6).

Telescopes will show the phase of the planet change from half to a thin crescent over the next two months, while the diameter of the disk swells from 24.5" to 55". You should be able to spot Venus as a tiny crescent in binoculars by the end of the year. The Moon is nearby on November 5th and December 4th, making for an attractive sight.

Still awaiting launch at time of writing is the European Space Agency’s Venus Express mission, designed to study the atmosphere and space-environment of Venus. Following launch, the spacecraft will take 153 days to reach Venus after which it will settle into orbit and begin science operations. Although previous missions such as Magellen have used radar to pierce the veil shrouding this mysterious world, we are still no closer to understanding

why Earth’s sister planet boasts a greenhouse effect run riot. Mars continues to steal the show as it reaches opposition on November 7th in the constellation Aries and shines at magnitude -2.3 throughout the night. The disk measures 20" at this time and the Red Planet is sure to be carefully scrutinised by backyard observers. Or so we hope! Recent reports on the International Mars-watch page (http://elvis.rowan.edu/marswatch/) suggest that a dust storm first noticed brewing on the planet in mid-October has now increased in intensity. Should the storm grow in size it will gradually obscure features for observers and the disk will look bright orange. Any reports you have should be forwarded to the Mars-watch web site mentioned above. A detailed article on observing the planet during this apparition can be found at http://www.tnni.net/~dustymars/Article_2005.htm The Moon is close to Mars on November 14th and December 11th. Jupiter necessitates an early rise as it is strictly a morning sky object during November and December. You will probably only first spot the cream-coloured planet from the second week of November onwards as its time of rising becomes progressively earlier ahead of the Sun. Jupiter shines at magnitude -1.7 at the moment and the disk is quite small (for Jupiter!), measuring 32". The planet moves from Virgo into Libra at the start of December. Look for the Moon nearby on the mornings of November 29th and December 27th. Saturn rises before midnight at the beginning of November and a little earlier each night until the end of the period covered by these notes. It brightens slowly from magnitude 0.3 to magnitude 0.0 during November and December as it closes in on its January 2006 opposition date.

The beautiful ring system is easily visible in a small telescope but if you’ve been keeping a keen eye on the planet the last few years you will notice that they are gradually closing up -- their Earthward tilt is now around 17.5°. It’s all to do with the inclination of Saturn’s orbit and ours; twice during Saturn’s 29 year long circuit of the Sun the rings appear edge-on to Earth-based observers as we pass through their plane. The rings will next be edge-on in September 2009 and will disappear from view in all but larger amateur telescopes.

The Ringed Planet is still a dramatic sight at the moment close to the Beehive star cluster in Cancer that was mentioned in the previous issue’s notes. With the Moon close to the planet too on the evenings of November 22nd and December 18th it will add to an already dramatic sight in binoculars. Details for Uranus, Neptune, and Pluto are beyond

Heads


viewing for the most part during this time. Data & Phases of The Moon Data Summary November: 5th: below Venus in evening sky 14th: Full Moon right of Mars 15th: Full Moon left of Mars 21st: Last Quarter above Saturn 28th: thin Crescent next to Spica in Virgo 29th: thin Crescent below Jupiter in morning 30th: Crescent right of Mercury in morning December: 4th: Crescent below Venus evening 11th: waxing Gibbous right of Mars 12th: waxing Gibbous left of Mars 18th: waning Gibbous right of Saturn 19th: waning Gibbous left of Saturn 27th: Crescent below Jupiter morning 29th: thin Crescent left of Mercury morning Phases New 1st Qtr Full Last Qtr Nov 2nd Nov 9th Nov 16th Nov 23rd Dec 1st Dec 8th Dec 15th Dec 23rd Dec 31st I.S.S. Passes As we come into winter, the angle of the ISS’s orbit means it can only be viewed either early evening or early morning, mostly occurring twice each day. Nov 3rd to Nov 20th: early evening object, with sometimes 2 passes occurring 93 minutes apart. Nov 21st to Nov 30th: not visible over Ireland. Dec 1st to Dec 17th: early morning object, almost twice each morning. Dec 18th to Dec 31st: not visible over Ireland. The passes are too numerous to list here, but if you have access to the web, check out the reliable and free www.heavens-above.com for a comprehensive list of passes –Ed. Asteroids While sourcing material for these sky notes I discovered that a reasonably bright asteroid for binoculars, (19) Fortuna, will be close to Mars during November. Fortuna reaches opposition on the night of November 4th when it can be found as a magnitude 8.9 speck of light 4.5° slightly north of east from Mars. Should the Irish weather cooperate

around this time, carefully draw the star field over a few successive nights. You’ll find that the “star” that moves will be the asteroid. The apparent gap between Mars and the asteroid actually shrinks to about 2.5° by the end of November but Fortuna’s brightness has declined somewhat to magnitude 9.8 by this time, making binocular observation rather more difficult. Fortuna was discovered on August 22nd, 1852 and lies 159 million kilometres from Earth when at opposition this year.

The asteroid ranked third in order of discovery, (3) Juno, is at opposition on December 9th in the eastern part of the constellation Orion. It peaks at magnitude 7.6 which is quite bright for Juno because this particular opposition occurs close to the asteroid’s minimum distance from the Sun in its eccentric 4.36 year long orbit. The asteroid falls within the same low power binocular field as Beta Eridani at this time, lying 3° northwest of the star. Meteors November The Taurids peak on the night of Nov. 3rd/4th in the constellation Taurus, high in the southeast at 9pm (as a guide). These average 10 per hour, with only a tiny sliver of the Moon on view, so it will be a dark night. The Leonids peak on Nov. 17th, but an almost full Moon will spoil the view – only the brightest of meteors will be seen. Leo rises after midnight from the east. Rates that we were familiar with in recent years (but were clouded out for) that occur every 33 years will not be realistically met, but this shower could still throw in a few surprises. December The Geminids peak on December 14th, but succumb to the nearly Full Moon. They can be considered even richer than the better known Perseids. The hours before midnight will probably be the most productive to observe The Ursids, peaking on Dec 22nd. The waning gibbous Moon rises just after 11pm and will interfere with your watch somewhat after that. The Ursid radiant is close to Kocab (Beta Ursae Minoris) and so the shower is visible all night from our latitude. Name Max ZHR Taurids Nov 4th 10 Andromedids Nov 14th 5 Leonids Nov 17th 30+ Geminids Dec 14th 25+ Ursids Dec 22nd 10 Skynotes Extra The Moon A favourable lunar libration close to the Full Moon of December 15th will tip the rugged southern highlands more towards us, allowing observers to view craters normally too close to the limb. It’s a fine opportunity to become acquainted with this terrain little explored by amateur


astronomers. Currently in orbit about our near neighbour is

SMART-1, Europe’s first lunar mission. It’s primarily a demonstration of new spacecraft technologies but ESA scientists are now engaged in a programme that will see the probe map the Moon’s surface in detail through to August 2006. Mars. Just mention the fourth world from the Sun and you conjure up many examples of our fascination with the Red Planet. Every two years or so, the Earth and Mars reach opposition, when Mars appears “Full” to the telescopic observer. It’s rather like what you get with Full Moon; the Sun lies directly opposite the Moon in the sky with the Earth sitting in the middle. To say it’s an exact straight line is a bit misleading but the example is sound.

Because Mars has a more eccentric orbit than us

some of these oppositions can be closer than others; that of August 2003 was touted as the closest in 58,000 years but we’re splitting hairs when compared to some of the close oppositions of the last 100 years. It was the widely studied oppositions of the 1890s coupled with the canal controversy that spurred H.G. Wells to write his classic “The War of the Worlds” which was published in 1898. Forty years later the tale was to terrify the populace of the eastern seaboard of America on Halloween when Orsen Welles and his Mercury Theatre Company broadcast a radio production based on the book, updating the original to an almost believable account of a Martian invasion of the US. This year, Mars is closest to Earth (but still 69.42 million kilometres distant) on October 30th. Make a point of glancing skyward at Mars around this time and ponder its continuing allure.

This chart is based at midnight on Dec 1st. For every 15 days before that, subtract 1 hour. Likewise, for every 15 days after

this time, add one hour.


Great Irish Women Astronomers By Girvan McKay, Tullamore AS Having read and heard a bit recently about the contribution made to astronomy by a number of remarkable Irish women, I think I can understand why some women become militant feminists. Women astronomers and scientists have had a raw deal – and not only in Ireland. We know a great deal about people like William Parsons, the Third Earl of Rosse, but how many of us can mention one female astronomer? Those of us who were at Cosmos some years ago, when Dr. Susan McKenna Lawler was a guest, can name one anyway, but she is by no means alone in her field.

Take the Irishwoman Agnes Mary Clerke, for

example. She lived from 1842 to 1907 and has been described as ‘the chief astronomical writer of the English-speaking world. She is commemorated in a crater on the moon which bears her name. Mary Ward (1827-1869), a first cousin of William Parsons is remembered as an early pioneer of the microscope rather than being involved in astronomy, but since both involve optics, the two activities are not unconnected. Mary Ward was the author of “Microscope Teachings” which helped to popularise the instrument.

Recently I heard a very interesting radio

interview with another outstanding Irish astronomer, Professor (Susan) Jocelyn Bell Burnell, born 1943 in Lurgan, Co. Armagh and educated at the Universities of Glasgow and Cambridge. The entry under her name in the Encyclopaedia of Ireland reads as follows: “While a postgraduate student at the Mullard Radio Laboratory, Cambridge, she collaborated with her supervisor Anthony Hewish, in constructing a radio telescope to investigate the scintillation of distant radio sources”.

It seems, however, from what she said during the interview that most of the work of construction was done by herself. She says that it was then that she learned to use tools, such as pliers, a skill that girls weren’t taught at her school. In 1967 she discovered the first known pulsar – a rapidly spinning neutron star of about twice the Sun’s mass which had collapsed to a sphere of only a few kilometres in diameter. She told the

interviewer that such a collapsed star is so dense that a piece of its material the size of a sugar cube would be as massive as our Earth. She managed the British support team of the international submillimetre-wave telescope in Hawaii. In 2001 she was appointed dean of science at the University of Bath. She has received nine honorary doctorates besides many other awards.

Without any show of resentment, Dr. Bell

Burnell mentioned how credit for the discovery of pulsars was given to the male astronomers she worked with. In the 1960s women scientists were not taken seriously. When the news broke of the pulsar discovery the team at the Radio Laboratory was swamped by reporters and photographers. All the scientific questions were fired at the men while the newspaper people were interested only in asking Dr. Bell Burnell personal questions, such as, did she have any boy friends and who was her present one? She was asked by the photographers to undo the top button of her dress for the photographers. Yet this was the person who made one of the most important astronomical discoveries of our time.

It was striking how mildly Dr. Bell Burnell

reacted to the way she was treated. During the radio broadcast she was asked what astronomers’ attitude was to religion. She replied that many were religious while others were not, and mentioned that she herself was of a Quaker background. She said that Quakers had a history of being involved in science because of their openness to freedom of thought and research. We can compare this with the way great scientists like Galileo were treated by the Church and the distrust of science by some United States fundamentalists today.

I hope we in TAS and Réalta readers will have a chance to learn more about pulsars and other distant bodies in space. It is a fascinating subject. Girvan McKay, TAS.

Editors Note: Its funny you should submit this Girvan. No sooner had I received your piece than I received thefollowing article next page by Deirdre Kelleghan from the Irish Astronomical Society, about her recent trip to TrinityCollege Dublin to see Dr. Burnell talk about Arthur Stanley Eddington (1882-1944). Read On…


Subject: Arthur Stanley Eddington Event: BA Festival of Science Lecture Sept 8th 2005 – Trinity College Dublin Speaker: Professor Jocelyn Bell Brunell – Oxford University –CBE By Deirdre Kelleghan, Irish AS “Oh leave the Wise our measures to collate One thing at least is certain, light has weight One thing is certain and the rest debate Light rays, when near the Sun, do not go straight” -A.S. Eddington Professor Brunell came to Trinity College Dublin not to speak about her own field of radio astronomy and her involvement in the discovery of pulsars. The great professor came to deliver a lecture on Arthur Stanley Eddington (1882-1944) an English born astronomer who was instrumental in expounding the theories of Albert Einstein. Jocelyn Bell Brunell has an interest in the public understanding of science and has a penchant to present physics topics among non-traditional groups.

A. S. Eddington was born in Kendal in 1882. As a child he had a fascination with numbers and Professor Burnell tells the anecdote of the child Eddington attempting to count all the stars in the sky and he was also driven to

count all the words in the bible. He excelled academically and did a maths degree in the short space of two years. Shortly after graduating he won the Smiths prize and was appointed to the Royal Observatory Greenwich where he improved and developed practical observational techniques. She relayed that Eddington was a popular member of “The Dinner Club” as he did not drink and if you sat beside him at dinner you were likely to get his share of wine as well. He was made secretary of The Royal Observatory Greenwich in 1912 and at the age of 31 he became Plumian Professor of Cambridge. Eddington never married or had children, he was a Quaker by faith and his primary belief that there is god and good within everybody was significant in his life in that he did not get caught up in the mass hysteria of anti-German feeling that permeated in Europe prior to the outbreak of WW1. Eddington was a pacifist and he avoided the war as a conscientious objector. He did get

called to account for his stance but still managed to get out of fighting by being proved far too valuable a scientist.

Eddington was one of the few people to read and understand Albert Einstein’s Theory of Relativity. At that time German scientists were being expelled from The Royal Society and the scientific work of Germans was hardly getting any attention from the rest of the world. Albert Einstein gave up his nationality in 1901 and became a Swiss citizen, but this failed to protect him from the welling anti German climate of the time. Eddington with his fundamental belief in the good in everyone set out to prove Einstein’s ideas in a practical way. He used the solar eclipse of May 29th 1919 to show one of the principals of Relativity. A know group of stars the Hyades star cluster is observed at night as usual, then in the unusual circumstances of a total solar eclipse the sun is observed against the same star cluster, some of the stars in this cluster appeared out of position as their light had bent around the mass of the sun. Sir Arthur Eddington stationed himself on an island off the western coast of Africa and sent another group of British scientists to Brazil. Their measurements of several of the stars in the cluster showed that the light from these stars was indeed bent as it grazed the Sun, by the exact amount of Einstein's predictions. Eddington’s team exposed 16 photographic plates in 5 minutes to capture the eclipse and the possible shift or apparent shift in the position of the stars. This research eventually confirmed Albert Einstein's theory that as light passes a very massive star; its path is bent due to gravity. Einstein became a celebrity overnight when the results were announced. Well this concept is not that easy to understand, so this is the way I thought about it, and it became clearer too me. The Hyades cluster is well known in the night sky Eddington knew that the Suns position on the 19th of May 1919 was in front of the Hyades cluster in daylight at the moment of the solar eclipse.


One would expect one or some of the stars to be masked by the Sun as it is a very massive star, as the solar eclipse revealed the Hyades cluster in the temporary night in the daylight at the moment of the solar eclipse. The sun in fact appeared to sit along beside them in the sky and caused the apparent position of a few of them to shift a bit. Eddington exposed photographic plates to record the eclipse and reveal that the stars of the cluster were not masked by the Suns mass, but the light from them was bent or curved by the Suns mass and gravitational field and continued to shine down on the earth, and appear on the developed plates.

As light from Stars is coming from a very great distance, it takes many thousands of years and light years to travel to our eyes or to Eddington's photographic plates.

The fact that the stars concerned appeared on his photographic plates and were not masked by the Sun, therefore Eddington proved this prediction of Einstein correct.

Because the light from a star is travelling through time and space - when it bends around a large mass like the Sun - therefore time and space are temporally bent or curved or misshapen. This effect occurs close to the Sun at the 96 million mile mark and it is then the kink happens. The apparent displacement of light results from the warping of space in the vicinity of the massive object through which light travels. The light never changes course, but merely follows the curvature of space. Astronomers now refer to this displacement of light as gravitational lensing.

According to Professor Brunell, Eddington was a wonderful communicator of science theory and was at the forefront of popularising Einstein’s work. There were few people in the world at the time that could understand the theory of Relativity yet alone explain it. A poster at the time announcing on of his talks on the subject claimed it was “A Book for 12 Wise Men” Arthur Stanly Eddington made Albert Einstein’s work popular and famous by his understanding and his desire to qualify Einstein’s theory for general consumption.

Professor Jocelyn Bell Brunell in her lecture on September 8th 2005 continued that wonderful achievement of clear communication for both Albert Einstein and Arthur Eddington.

In his honour several items have been named after Eddington. The Eddington crater on the moon is the remains of a lava flooded lunar impact crater, it is on the western edge of Oceanus Procellarum. To the west is the Struve walled plain to the east/southeast is the prominent Seleucus crater and south of Eddington is Krafft crater. In physics the Eddington Limit is a natural limit to the luminosity of a star. It is a way of describing the density of luminous intensity in a direction from the star, in relation to how much more the object radiates energy compared to our Sun. Accretion is an increase in size by the gradual addition of smaller parts, and in astronomy is a description of a gravitational process by which bodies like planets and stars form from gas and dust.

The European Space Agency had a comprehensive plan for The Eddington Space Telescope, which would have been a very sensitive device for mapping the evolution of stars. It was to be launched in 2008, the decision was taken

to cancel the Eddington mission but several of its science packages will it is hoped make their way onto other missions to search for other habitable planets and to study the stars of our universe. On enquiring with The European Space Agency about the Eddington Mission this was the reply “Many thanks for your email enquiry concerning the Eddington Mission. As things currently stand the Eddington mission is cancelled, although it is possible that the mission could resurface at some point in the future There is a PDF document to be found by following this link that outline the scope of the Eddington mission” http://sci.esa.int/science-e/www/object/doc.cfm?fobjectid=35806 I would like to acknowledge and thank Professor Jocelyn Bell Brunell, for her kind advice and support in the development of this article.

-Deirdre Kelleghan.


A Wrinkle in Space-Time By Trudy E. Bell When a massive star reaches the end of its life, it can explode into a supernova rivalling the brilliance of an entire galaxy. What’s left of the star fades in weeks, but its outer layers expand through space as a turbulent cloud of gases. Astronomers see beautiful remnants from past supernovas all around the sky, one of the most famous being the Crab Nebula in Taurus.

When a star throws off nine-tenths of its mass in

a supernova, however, it also throws off nine-tenths of its gravitational field.

Astronomers see the light from supernovas. Can they also somehow sense the sudden and dramatic change in the exploding star’s gravitational field?

Yes, they believe they can. According to Einstein’s general theory of relativity, changes in the star’s gravitational field should propagate outward, just like light—indeed, at the speed of light. Those propagating changes would be a gravitational wave.

Einstein said what we feel as a gravitational field arises from the fact that huge masses curve space and time. The more massive an object, the more it bends the three dimensions of space and the fourth dimension of time. And if a massive object’s gravitational field changes suddenly - say, when a star explodes - it should kink or wrinkle the very geometry of space-time. Moreover, that wrinkle should propagate outward like ripples radiating outward in a pond from a thrown stone.

The frequency and timing of gravitational waves

should reveal what’s happening deep inside a supernova, in contrast to light, which is radiated from the surface. Thus, gravitational waves allow astronomers to peer inside the universe’s most violent events—like doctors peer at patients’ internal organs using CAT scans. The technique is not limited to supernovas: colliding neutron stars, black holes and other exotic objects may be revealed, too.

NASA and the European Space Agency are now building prototype equipment for the first space

experiment to measure gravitational waves: the Laser Interferometer Space Antenna, or LISA.

LISA will look for patterns of compression and

stretching in space-time that signal the passage of a gravitational wave. Three small spacecraft will fly in a triangular formation behind the Earth, each beaming a laser at the other two, continuously measuring their mutual separation. Although the three ‘craft will be 5 million kilometres apart, they will monitor their separation to one billionth of a centimetre, smaller than an atom’s diameter, which is the kind of precision needed to sense these elusive waves. LISA is slated for launch around 2015. To learn more about LISA, go to http://lisa.jpl.nasa.gov. Kids can learn about LISA and do a gravitational wave interactive crossword at http://spaceplace.nasa.gov/en/kids/lisaxword/lisaxword.shtml

LISA’s three spacecraft will be positioned at the corners of a triangle 5 million kilometres on a side and will be able to detect

gravitational wave induced changes in their separation distance of as little as one billionth of a centimetre.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the

National Aeronautics and Space Administration.


Goldilocks and the (many) more than three planets: some notes on Astrobiology By Girvan McKay, Tullamore AS What is Astrobiology? I hope I hear you ask. According to my encyclopaedia: Astrobiology is defined as: “The multi-disciplinary study of the origin, distribution and destiny of life in the universe. It addresses the questions of how does life begin and develop, does life exist elsewhere in the universe, and what is life’s future on Earth and beyond. It is a major goal of NASA’s science programmes.”

The study of Astrobiology (also known as Exobiology) is above all associated with the name of the late Carl Sagan, who is also regarded as the first astrobiologist. In a way it’s a little strange to refer to it as a study, since to study anything you have to have some data to study. In this sense Astrobiology is like Theology, which purports to be the study of God. But if God, by definition, is invisible and unknowable, what is there to study? It isn’t even possible to prove the existence of God by either argument or research.

The same applies to Astrobiology. We don’t

know whether there is any kind of life outside of our own planet Earth. But in both cases, the search still goes on. Also, in both cases, it’s a matter of faith rather than proof. We haven’t as yet found any evidence of extraterrestrial life. Within our own solar system investigations are still being carried on to see if there is any evidence of existing or extinct life on Mars. So far nothing has been found although US scientists claim to see signs that there was once water there, and liquid water often indicates the presence of life. There are also hopes that there might be liquid water under the surface crust of Europa, Jupiter’s second satellite.

You’ll realise, of course, that the search for life

doesn’t necessary mean the search for intelligent life. Probably most astrobiologists would be happy if they discover any kind of life elsewhere in the solar system or outside it. They would be jumping up and down with joy if even all they found were something like a bacterium, an amoeba, a fungus, a lichen, a slime mould or anything else that was alive, even if it couldn’t read,

write or think and looked like something in your dist bin or on mouldy cheese.

Also associated with Carl Sagan and Astrobiology is the SETI programme, although this is the search for extraterrestrial intelligence - in other words for intelligent life, not just any kind of life. Back in November 2001 I gave a talk on ‘Life in the Universe’ in which I mentioned the SETI programme. For those of you who weren’t at that TAS lecture or who fell asleep during it, I’ll digress for a moment to say something about SETI.

SETI was a research programme originally

managed by NASA’s Ames Research Centre. It was aimed at using large radio telescopes to try and detect artificially generated radio signals from interstellar space. (I’m quoting here from another article in my encyclopaedia.) The hypothesis behind the belief that life might exist elsewhere in our galaxy is based on telescopic and spacecraft evidence that organic molecules are common in space and also on the hypothesis that planetary formation is a common by-product of star formation. The SETI programme was first proposed in 1959 and thirty very limited searches were carried out. It was an American astronomer called Frank Drake who in 1960 was the first person to conduct a radio search for signals from extraterrestrial civilisations.

Drake is mainly associated with an equation he proposed to organise this search. (By the way, Drake says himself that he only meant his equation as a gimmick and he was surprised when it was taken seriously and is now included in astronomy textbooks.) Here is the equation:

N = R* fp n e fl fi f c L The factors indicate the following: R* , the number of stars; fp , the number of stars with planets; n e , the number of planets with habitable environments; fl , the fraction of these on which life has originated; fi , the number with intelligent life;


f c , creatures with the technology to send out signals; and L, the longevity of civilisations. N is the number of stars meeting all these criteria. Of all the factors in the equation only one, R*, is anywhere near to being understood. It represents the number of stars and we do know that there are a lot of them - more than 100 thousand million, or maybe as many as 400 thousand million in our galaxy alone. Eventually with the help of what they call the Terrestrial Planet Finder or TPF (a piece of equipment that has not yet been developed) that the researchers hope to solve the third factor in the Drake equation, n e, the number of planets with inhabitable environments. They might even be able to solve factor fl , those on which life has originated.

TPF would capture the feeble light from a

distant rocky planet, while cancelling out the far more brilliant light of its star. The amount of planetary light they could detect might amount to only one pixel. This minute quantity of light could then be examined for what are called the spectral signatures of, for example, oxygen, methane, ozone or some other clue to the possible presence of life.

The forms of life that we know on Earth are

dependent on liquid water and organic molecules, mostly made up of carbon. But even on Earth, the huge and widely differing conditions under which life can exist are amazing. Life is found in the sea and on land; in almost waterless desert conditions; in the Arctic and in the tropics; in the darkest depths of the ocean; in deep caves - and, in fact, almost anywhere. Some life forms can go without food for months and even years; some can lie dormant for great lengths of time and then seemingly revive; some can get their nourishment by dissolving rock and living off the chemicals in it.

It’s also been suggested that there might be other forms of life in the universe quite unlike anything on Earth: life based perhaps on silicon instead of carbon; life that drifts in the atmosphere above a planet, and so on.

A new SETI programme was initiated in 1992 at the world’s largest radio telescope at Arecibo, Puerto Rico. In 1993 the US Congress withdrew its support for the programme, but it has been continues under private sponsorship. In May 1999 the SETI@home project was set up. This harnessed the power of millions of home

computers to analyse signals picked up by a detector on the Arecibo radio telescope. So far results have been disappointing in spite of 40 years of searching. On one occasion it was thought that what might be an artificial signal had been detected, but it wasn’t repeated and it couldn’t be confirmed as anything out of the ordinary.

What seems to be a more promising line of investigation than the SETI programme is the search for stars, which might have planets orbiting them. In 1994, a Ph.D. student at the University of Geneva called Didier Queloz saw that a star he was observing appeared to be rocking back and forth. This phenomenon of wobbling stars has since been discovered to indicate the presence of a planet orbiting the star. With the existing technology in the nineteen nineties it was quite impossible to see such a planet, even with the most powerful optical telescopes, but it is hoped that it will become possible to mask the strong light from a star so as to enable observers to see at least its largest planets. This has been compared to seeing a firefly in the beam of a searchlight or lighthouse many miles away. By the year 2000 astronomers had detected at least 22 planets outside our solar system thanks to this discovery of star wobble and their number is continually increasing as more and more are discovered. So far, only very large planets are detectable by this means: gas giants or planets with a mass much greater than that of the Earth. Researchers are calling these remote gas giants ’Jupiter’s’ after the planet of that name in our own solar system.

What haven’t been found yet are rocky planets

of a size similar to our planet, which is considered to be the best habitat for forms of life similar to those on Earth. Astronomers have taken to calling these ‘Goldilocks Planets’. You’ll remember that in the story the little girl Goldilocks finds the house of the three bears, tries sitting on their chairs, eating their porridge and sleeping in their beds. The porridge is too hot, too


cold or just right, while the chairs and beds are too big, too small or just right. A suitable planet would have to be not too close to its star to be too hot for life; and not too far away from it to be too cold for life; not too big to have a crushing gravity; and not too small so that it loses its atmosphere. With the discovery of these other solar systems in our galaxy, more and more astronomers are becoming convinced that other planets like ours exist in the universe.

A year or two ago David Bell (from Shannonside AC) gave us a lecture in which he argued the case for the view that our Earth might be the only planet on which life had emerged. He said at the time that he was taking up this position to provoke discussion and that he could equally argue for the opposite view that life was common throughout the universe. It seems that fewer and fewer astronomers are inclined towards what we might call the anthropocentric view, i.e. that we are unique in the universe and that Earth is the only planet where life has arisen.

This is the kind of attitude that Galileo had to face when he said that the Earth went round the Sun and not the other way round. When you think how many countless millions of stars are in our galaxies and how many countless millions of galaxies there are in the universe, and how the building blocks of life can be detected even in deep space, it seems inconceivable that life is not to be found elsewhere. So the search for extraterrestrial life goes on. The National Geographic magazine has published a table showing the progress of this search as follows: 1992: Arecibo Radio Telescope Scientists announce the discovery of planets around a pulsar. They are unlike any known planets and are almost certainly hostile to life, but they are the first alien planets to be found. 1995: Haute-Provence Observatory (France) Astronomers discover a planet around a sun-like star, 51 Pegasi, by tracking stellar motions. The same technique has revealed more than 130 planets. 1999: STARE Project For the first time the shadow of a Jupiter-size planet is detected as the planet passes over the face of its star, HD 209458.

2001: Hubble Space Telescope By observing light from HD 209458 as its planet passes, astronomers see hints of a planetary atmosphere containing sodium. 2003: Keck Interferometer This equipment combines light from the two existing Keck telescopes, eliminating atmospheric ‘noise’ with what’s called adaptive optics. It searches for debris disks around stars, which could indicate planet formation, and look directly for giant planets. 2006: Large Binocular Telescope The twin mirrors of this telescope will search for debris disks and for newly former Jupiter-size planets. 2007: Kepler Mission This space-based telescope will survey more than 100,000 stars for dimming that hints at the presence of Earth-size planets. 2009: Space Interferometry Mission (SIM) This will combine light from multiple telescopes to map stars and seek planets almost as small as Earth. 2014-2020: Terrestrial Planet Finder (TPF) A two-part space mission to detect light from Earth-size planets, and search for signs of habitability. 2025: Life Finder The Space-based Life Finder will search newfound Earths for signs of biological activity. So the first part pf this challenging programme has been achieved: We know now that there are other solar systems besides our own. Other stars have planets. Now it remains to be discovered whether any of these might sustain life; what that life might be like; and last of all, whether any such life forms could be intelligent. Man has ever undertaken probably no more exciting research. This article, by Girvan, was the basis for a lecture he gave to TAS on Tuesday October 11th. It provided a good debate afterwards, where so many avenues of discussion about the possibility of life, both as we know it, and not, and where it could exist.


Where No Spacecraft Has Gone Before By Dr. Tony Phillips In 1977, Voyager 1 left our planet. Its mission: to visit Jupiter and Saturn and to study their moons. The flybys were an enormous success. Voyager 1 discovered active volcanoes on Io, found evidence for submerged oceans on Europa, and photographed dark rings around Jupiter itself. Later, the spacecraft buzzed Saturn’s moon Titan—alerting astronomers that it was a very strange place indeed! —and flew behind Saturn’s rings, seeing what was hidden from Earth.

Beyond Saturn, Neptune and Uranus beckoned, but Voyager 1’s planet-tour ended there. Saturn’s gravity seized Voyager 1 and slingshot it into deep space. Voyager 1 was heading for the stars—just as NASA had planned.

Now, in 2005, the spacecraft is nine billion miles (96 astronomical units) from the Sun, and it has entered a strange region of space no ship has ever visited before.

“We call this region ‘the heliosheath.’ It’s where the solar wind piles up against the interstellar medium at the outer edge of our solar system,” says Ed Stone, project scientist for the Voyager mission at the Jet Propulsion Laboratory.

Out in the Milky Way, where Voyager 1 is trying to go, the “empty space” between stars is not really empty. It’s filled with clouds of gas and dust. The wind from the Sun blows a gigantic bubble in this cloudy “interstellar medium.” All nine planets from Mercury to Pluto fit comfortably inside. The heliosheath is, essentially, the bubble’s skin.

“The heliosheath is different from any other place we’ve been,” says Stone. Near the Sun, the solar wind moves at a million miles per hour. At the

heliosheath, the solar wind slows eventually to a dead stop. The slowing wind becomes denser, more turbulent, and its magnetic field—a remnant of the sun’s own magnetism--grows stronger.

So far from Earth, this turbulent magnetic gas is curiously important to human life. “The heliosheath is a shield against galactic cosmic rays,” explains Stone. Subatomic particles blasted in our direction by distant supernovas and black holes are deflected by the heliosheath, protecting the inner solar system from much deadly radiation.

Voyager 1 is exploring this shield for the first time. “We’ll remain inside the heliosheath for 8 to 10 years,” predicts Stone, “then we’ll break through, finally reaching interstellar space.” What’s out there? Stay tuned… For more about the twin Voyager spacecraft, visit voyager.jpl.nasa.gov. Kids can learn about Voyager 1 and 2 and their grand tour of the outer planets at spaceplace.nasa.gov/en/kids/vgr_fact3.shtml .

Voyager 1, after 28 years of travel, has reached the

heliosheath of our solar system.


News

Russian Spacecraft Fails to Boost ISS into Higher Orbit

A Russian spacecraft stopped short of boosting the International Space Station (ISS) into a higher orbit on Tuesday October 25th when its engines unexpectedly shut down in mid-manoeuvre, Russian space officials said. After the first turn-on of the engines, they turned off spontaneously.

The failed orbital manoeuvre poses no danger to the ISS or its two-astronaut crew, Expedition 12 commander Bill McArthur and flight engineer Valery Tokarev, and engineers are currently studying the glitch, according to a Federal Space Agency statement. There is no forecast at the moment as to when they would try again. Russian and U.S. space station flight controllers were expected to perform two engine burns that day using the Progress 19 spacecraft’s engines evening to raise the ISS into a higher orbit. The spacecraft is docked at the aft end of the station’s Zvezda module.

The engine burns, each scheduled to run 11 minutes and 40 seconds, were expected to raise the ISS into an orbit that hits 224 statute miles (360 kilometres) at its highest point, a bit higher that the station’s current

orbital peak of 220 statute miles (354 kilometres), NASA officials. But the Progress engines switched off less than two minutes into the first burn, NASA officials said, adding that there appeared to be a communications problem between the spacecraft's thrusters and Russian navigation computers, which shut down the engines as designed due to the data dropout.

The brief engine burn did accelerate the ISS by about 1.04 feet per second (0.31 meters per second) and raised the lowest point of the station's orbit - 211 miles (339 kilometres) - by about 0.7 miles (1.1 kilometres).

Other engines could be used to boost the space station’s orbit, but Russian space officials are still evaluating the glitch Tuesday’s altitude-raising manoeuvre was slated to place the station into the proper position for a second orbital boost later this year that would set up the ISS to receive an unmanned Russian-built cargo ship – Progress 20 – slated to launch toward the space station on December 21st.

Progress 20 will ferry vital supplies, spare parts and equipment to McArthur and Tokarev, who began their six-month tour aboard the ISS in October.

Contamination cleanup continues on Venus Express orbiter

European scientists are reasonably confident their Venus Express spacecraft will launch to Earth's nearest neighbour before the tight window of opportunity when the planets are aligned slams shut in a few weeks. The mission was supposed to blast off on Wednesday October 26th, from Baikonur Cosmodrome in Kazakhstan. But contamination found on the satellite forced launch preparations to stop, putting Venus Express into an unplanned holding pattern.

The spacecraft was already mated to its Soyuz rocket inside an assembly building in advance of being rolled to the launch pad.

Then came the discovery of some insulation material that had come off the Fregat upper stage and was floating free inside the rocket's nose cone where Venus Express sat encapsulated for launch.

Over the previous weekend, the Fregat and spacecraft still tucked inside the nose cone were detached from the Soyuz for train transport to another facility 25 miles away. The shroud was opened that Monday, enabling inspections of Venus Express by technicians to determine if any damage had occurred by the insulation.

"The scenario is so far very encouraging, as only fairly large particles, pieces of the

insulating material initially covering the launcher's Fregat upper stage, have been found on the body of the spacecraft," ESA said in a press statement.

"These have been easy to identify by naked eye or with UV lamps, and are being carefully removed with tweezers, vacuum-cleaners or nitrogen gas airbrushes, according to size."

The cleaning will continue, followed by re-installation of the nose cone and transfer back to the Soyuz rocket's assembly building. Although a new launch date has not been set, lift-off is expected to be targeted for sometime between November 6 and 9. Venus Express must launch by November 24 to

SPACEFLIGHT


catch the necessary trajectory from Earth to its destination. The probe should reach Venus five months after launch. It will fire the onboard main engine to enter orbit around the planet for the most comprehensive examination of the mysterious Venusian atmosphere and new observations of its surface.

Venus Express will fly in a highly elliptical orbit looping from 155 miles at its closest point to 41,000 miles at the most distant.

The EADS Astrium-built craft carries seven instruments mostly derived from Europe's Mars Express and the Rosetta comet mission. The mission, Europe's first exploration of Venus, will last two Venusian days or 486 Earth days. Editors post-script… Just before this article was sent to print, the following was issued (taken from space.com):

Russian space officials Monday set a Nov. 9 blastoff for a European probe to explore Venus after its earlier launch was postponed because of a booster rocket problem. Engineers will be able to fix the flaws by that date, the Federal Space Agency said in scheduling the launch at the Russian-leased Baikonur Cosmodrome in Kazakhstan.

Japanese spacecraft ready to land on asteroid Nov 12 Japan’s Hayabusa asteroid sample-return satellite is scheduled to make the first of two landings on its target asteroid on November 12th following ground controllers’ conclusion that it has enough fuel to finish its job despite the loss of two of its three reaction wheels,

the Japanese space agency, JAXA, announced.

Under current planning, a second touchdown would occur November 25th before Hayabusa, whose name was Muses-C before its May 2003 launch, begins a return flight to Earth. Since September 12th, the satellite has been stationed several kilometres from the Itokawa asteroid, which is some 300 million kilometres from Earth.

Hayabusa lost the use of its first reaction wheel in July. The second failed October 3rd, forcing increased reliance on the chemical-

propellant thrusters to maintain satellite attitude control.

JAXA said the Hayabusa project engineers have made “a strenuous” effort to devise a fuel-conservation plan to maintain Hayabusa stably in position and at the same time provide for the two “touch-and-go” manoeuvres during which the satellite will scoop up asteroid samples.

JAXA will test Hayabusa touchdown manoeuvres November 4th with what the agency calls a “rehearsal descent.” Several candidate landing sites are still being evaluated, JAXA said.

Mars rover Spirit begins descent from summit

Spirit, the robot on wheels that reached the top of a Martian hill this summer after an epic climb, is heading back down toward its next target for exploration. After two months at the summit of Husband Hill, the six-wheeled rover is descending to a basin where the scientific instruments it carries will examine an outcrop dubbed "home plate" because from orbit it looks like home on a baseball field.

Spirit's yearlong climb to the peak was a major feat for the Mars rover, which along with its twin, Opportunity, landed on opposite sides of the Red Planet in January 2004.

Last month, scientists released the first full-colour panoramic photo of the landscape taken by Spirit from the 270-foot-high summit. It shows the rover's distinct tracks in the dust, the flat plains of the

surrounding Gusev Crater region and distant plateaus on the crater rim.

Spirit also has been studying rocks and using its robotic arm to sift the soil to determine how the hill formed. The leading theory is that Husband Hill became uplifted as a result of crater impact.

Mission scientists say a comparison of the summit rocks reveal similar geologic features to those found on the side of the hill. In both cases, the rocks' makeup reveals they have been altered by water.

It will take about two months for Spirit to make it all the way down Husband Hill, which is named after Rick Husband, the commander of the space shuttle Columbia that broke apart as it was returning from Earth orbit in 2003.

Meanwhile, Opportunity is in good health again after recovering from a recent computer glitch while surveying the Meridiani Planum region.


Contributions Wanted Do you ever notice that it is the same people that submit something for Réalta? Sometimes, it can be unfair to expect the same people to keep something like this going. That is why I want you to think of a contribution, of any kind, that you would like to share with readers. It can be about something you read in a magazine somewhere, r a recap on a nights observing,

telling us what you saw, or even an article you penned yourself. Variety is good, and while Réalta has had many, MANY interesting articles on its pages, it is the same few people that keep doing the good work! So have a think about it – contact details are at the bottom of this page.

-Ed.

‘Lecturers’ Wanted! In addition to Réalta contributions, TAS is also looking for folks to volunteer a small amount of their time to give a talk to the club. You do not need to be a professor, or have any distinct qualifications. Just the ability to stand in front of members and friends and talk

about some astronomy topic that you choose. We will even help you along! Have a word with any committee member at any meeting if you “want to know more”, or e-mail the Secretary: [email protected]. New faces and voices are always welcome!

Réalta – Volume 7, Issue 2: November/December 2005. Réalta is issued by the Tullamore Astronomical Society as a community-based organisation magazine.

Editor:

Seanie Morris

Contributors this issue: Trudy E. Bell, Darren Dempsey, John Flannery, Deirdre Kelleghan, Girvan McKay, Michael O’Connell, Tony Phillips

Editorial & Submissions Address:

C/o Seanie Morris, ‘ANSTEE’, Daingean Road, Tullamore, Co. Offaly, Ireland. Email: [email protected]. Submissions are welcome, preferably by email or on disk (MS .txt or .doc format), but submissions on paper are also very welcome. Please acknowledge any reference sources for your

submission.

Printed By: Aungier Print Ltd., Sackville House, Sackville Place, Dublin 1. Tel: 01-8788406/7 or Email: [email protected]

All articles contained are © Réalta & Tullamore Astronomical Society, and the source of the articles (if stated).

© Réalta 1997-2005. All Rights Reserved.

Know someone who could use a 2006Calendar? Then why not tell them toget one of ours! You already knowwhat it is about, but do you also knowthat proceeds from this go to helpTAS build a public accessible meetingroom/clubhouse, and refurbish itsobservatory? TAS relies on fundinglike this to get the project finished,which, when complete, willincorporate a comfortable meetingroom and kitchen, as well as accessto our observatory with telescope forastronomy enthusiasts and research.The Calendar is available from anycommittee member, or direct fromByrne’s World of Wonder (Tullamore& Mullingar), priced €10.00.

Réalta – Volume 6, Issue 3 – April/May 2005 – Tullamore Astronomical Society 24

How To Find TAS’s Meeting Nights

Tullamore Astronomical Society hold their talks and classes in astronomy on TUESDAY nights, in the Order of Malta Training Room. Meetings start at 8pm, are informal, and free to attend. Weather permitting, light observing will take place in the car park afterwards. On the dedicated Observing Nights, members meet in the car park in front of Tullamore Carpets/Hire Depot at 8pm, and head out to the Observatory together. For more information, contact the club at: [email protected]

9+- EALTA The Midlands Publication of the Tullamore ... · PDF fileDeirdre Campbell helps out....

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