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Journal of the Amateur Astronomers Association of New York March 2008 Volume 56 Number 3, ISSN 0146-7662

EYEPIECE
harnessing of these waves for scientific research. It consists of two widely separated installations, designed and constructed by the California Institute of Technology and the Massachusetts Institute of Technology and operated in unison as a single observatory. It was funded by the National Science Foundation (NSF) and is available to the national scientific community as part of a growing worldwide network of gravitational-wave observatories.

The Intensifying Search for the Elusive Gravitational Wave
By Edward J. Fox
One of Einstein's predictions of gen er a l r ela t ivit y --the existence of elusive gravitational waves--wasn't proved during his lifetime. About 30 years ago, waves were observed in an indirect way thanks to observation of the influence of gravitational waves on the behavior of a binary star. It was measured accurately and is in good agreement with the predictions. Scientists, therefore, have great confidence that Einstein was correct, that gravitational waves exist.
Similar to the emission of electromagnetic waves by accelerated electrical charges, the acceleration of masses leads to the emission of gravitational waves, consisting of ripples propagating through the space-time continuum. They're produced by violent events in the distant universe, such as the collision of two black holes or the cores of supernova explosions. These ripples in the space -time fabric travel to Earth, bringing information about their violent origins and the nature of gravity. These exotic phenomena wer e d iscu ssed a t t h e February 1 AAA lecture by Nergis Mavalvala, associate professor of physics at MIT, when she spoke on "Detecting Gravitational Waves: LIGO and the Search for the Elusive Wave." "The business of detecting gravity waves is very difficult since they are so weak and of such low frequency," Mavalvala said. Several existing and planned experiments around the world are trying to observe these ripples directly, by looking for extremely small changes in the lengths of "measuring rods" (e.g., length of a solid cylinder, or distance between two mirrors). LIGO stands for the Laser Interferometer Gravitational-Wave Observatory, one of the facilities dedicated to the detection of cosmic gravitational waves and the

NSF selected sites n ea r L ivin gst on , L a ., a n d a t Hanford, Wash., for LIGO installations. The sites are flat and large enough to accommodate two 2.5-mile interferometer arms arranged in an L formation. The sites must be far apart because local phenomena, such as micro-earthquakes, acoustic noise and laser fluctuations, which cause a disturbance at one site, simulating an apparent gravitational-wave event, are unlikely to happen simultaneously at the other site. At the vertex of each L and the end of each of its arms are test masses hanging from wires and fitted with mirrors. The main building at the vertex is the control center and houses vacuum equipment, lasers and computers. Ultrastable laser beams traversing vacuum pipes measure the effect of the waves on the test masses. When gravitational waves en t er t h e L I G O d et ector, they decrease the distance between the test masses in one arm of the L while increasing it in the other. These changes are minute: just 10-16 centimeters, or onehundred-millionth the diameter of a hydrogen atom over the 4-kilometer length of the arm. These tiny changes can be detected by bouncing high-power laser light beams back and forth between the test masses in each arm and then interfering the two arms' beams with each

Search continued on page 7


What's Up
By Tony Hoffman The Sky for March 2008
Messier Marathon Time. Ast r on om ica lly, t h e Vernal Equinox marks when the Sun crosses the celestial equator, heading northward, on its journey around the celestial sphere. (Of course, it's really the Earth that's journeying as it orbits the Sun, and the Sun's seeming northward swing is due to the changing orientation of the Earth's axis in relation to the Sun--though the axis itself remains fixed in space, with its north pole pointed near Polaris.) The Vernal Equinox, or more precisely the New Moon(s) nearest the equinox (this year March 7 or April 5), is the best time to try for a Messier Marathon, an opportunity to see nearly all 109 objects in Charles Messier's catalogue of "comet imposters" (which today we know as star clusters, nebulae, and galaxies) over the course of a very long night. To succeed, you need clear, dark skies, horizons as unobstructed as possible, decent equipment and a bit of preparation. As the sky darkens, the objects that dazzled us in autumn such as the Andromeda Galaxy are sinking into the west, while Orion and winter's finest, with their bright open clusters and nebulae, are near their highest. The winter Milky Way bisects the early evening sky, from Cepheus in the north up through Cassiopeia and Perseus, to Auriga and Gemini nearly overhead, to Monoceros, Canis Major and Puppis to the south. The spring constellations are already rising. Many a Messier marathoner has hit a wall in the Virgo Cluster of galaxies, a number of which belong to the Messier Catalogue and may be hard to distinguish one from another. In the predawn hours, summer constellations and numerous deepsky objects surrounding the center of the Milky Way in Scorpius, Sagittarius and Ophiuchus take center stage. Happy yet exhausted hunters will scramble for their final objects as predawn light starts filtering into the sky. Even if you don't complete the marathon, or don't come anywhere near completing it (the best I've managed is about a half-marathon), the hours you spend searching for these objects, familiar and elusive, are sure to be time well-spent. Ceres Passes the Pleiades. I n la t e 2006 t h e a st er oid 7 Iris, during an unusually bright apparition, passed
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Mercury and Venus make a close pair around March 4 in the predawn sky.

close to the Pleiades star cluster in Taurus. Late this month, we're treated to an encore, as Ceres scoots by the Pleiades. This worldlet, 595 miles in diameter, was the first asteroid to be discovered, in 1801. (Even though it was reclassified as a "dwarf planet" in 2006, I seldom see Ceres referred to as such.) Between March 22 and 27, Ceres lies within 5 degrees of the Pleiades. At 9th magnitude, it will be a difficult binocular object from the city, and easier in a telescope. March 2 Moon lies near Jupiter. March 3 Mercury at greatest elongation in morning sky. March 5 Moon lies near Mercury and Venus. March 7 New Moon at 12:14 p.m. March 10 M oon a t p er igee, 227,607 m iles fr om E a r t h , 5:39 p.m. March 14 F ir st -quarter Moon at 6:46 a.m.; Moon lies near Mars. March 19 M oon lies n ea r R egu lu s a n d Sa t u r n . March 20 Ver n a l eq u in ox a t 1: 48 a .m . March 21 F u ll M oon a t 2: 40 p .m . March 23 M er cu r y lies a d egr ee fr om Ven u s. March 27 M oon lies n ea r An t a r es. March 29 L a st -quarter Moon at 5:47 p.m. March 30 M oon lies n ea r J u p it er .

Jupiter Reappears in Morning
By Joseph A. Fedrick
Jupiter reappeared in t h e m or n in g sk y, low in t h e morning twilight near the southeast horizon in late January after being hidden in the solar glare for more than a month. I had last seen Jupiter in late November as it sank low in the southwest soon after sunset. In the closing days of January, I saw Jupiter about 10 degrees to the lower left of Venus. I watched Venus close in gradually


A Message from AAA President Richard Rosenberg
Hello, members: On February 27, the AAA board of directors chose a nominating committee, whose task is to choose a slate of club members for election to the board. At the annual meeting May 21, we will choose among members of this slate and any others who have qualified by obtaining 18 signatures of members on a petition. Our board consists of 18 members. Members serve three-year terms, with six elected each year. Perhaps you're interested in serving the club as a board member. The board meets four times a year. Each May, after our annual meeting, it chooses from its own members the officers for the coming year: the president, vice president, treasurer, financial secretary, corresponding secretary and recording secretary. The officers carry out the daily business of the club, while the board oversees them. The president is the chief executive officer of the club, and selects chairs to run club events. The vice president assists the president. The treasurer is the chief financial officer of the club, assisted by the financial secretary, who handles and records receipts and deposits. The corresponding secretary handles correspondence with individuals and organizations. The recording secretary takes and distributes minutes of meetings of the board, officers and the annual meeting. Other members of the board chair club events such as observing sessions and our seminar, or have specialized skills: auditor, lawyer, editor, webmaster or public-relations specialist.

If you're interested in serving on the board, let nominating-committee chair Dan Harrison know (editor@aaa.org) know and he'll schedule a meeting with the nominating committee. If you don't have time to be a board member but want to help the club in some way, from writing articles in Ey epiece to helping with mailings to setting up new observing sessions, contact me as well.
Rich Rosenberg, AAA President, pr esident @a a a .or g, (718) 522-5014

March 7 AAA Lecture
At presstime, the March 7 AAA lect u r e sp ea k er was undetermined. Columbia University's Eric Gotthelf, the scheduled speaker, bowed out due to the press of a research project. Please check our website, www.aaa.org, for updated information on the lecture. The 2007-08 AAA lecture series will fea t u r e t h ese other speakers: April 11: E r ic M yer s, L I G O H a n for d O b ser va tory, "Searching for Ripples in Space-Time with your Home Computer"; May 2: Ar lin C r ot t s, C olu m b ia University, "Liquid Mirror Telescopes Are Looking Up."

Reconstructing Mars
The 2007-08 season for ob ser vin g M a r s h a s com e and gone. As Joe Fedrick pointed out in last month's issue, the weather was dismal. Generally in the past, I recall winter nights of observing Mars when there was crystal-clear seeing, but it was not to be. The best night I had for observing Mars came on the morning of January 4. I had observed hints of tantalizing detail between midnight and 1. The weather was cold but the sky was clear, with strands of a few cirrus clouds above me. I did a quick sketch and as always, consulted a map of Mars later to confirm what I had drawn. I had this image in t h e b a ck of m y m in d . I r em em Mars continued on page 5
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Super Collider: Unlocking the Secrets of the Universe
By Edward J. Fox
The largest machine in the world is b ein g b u ilt t o observe the smallest particles. It's the Large Hadron Collider (LHC), nearing operation in May outside Geneva, straddling the French-Swiss border. It's meant to recreate the conditions a fraction of a second after the Big Bang, so that physicists can understand what happened. On January 14 at the Hayden Planetarium, Christopher Tully and Nima Arkani-Hamel of Princeton University respectively described the experimental nature of the facility and the theory behind its development. Tully, an experimental high-energy particle physicist, described the physical facility and its mechanics. Arkani-Hamel, a particle-physics theorist, explained the evolution of the theories which have led to the point where such a machine is necessary to expand our knowledge of the universe by testing current theories. Tully illustrated the size of the facility by comparing it to known objects. The LHC is a series of tubes, some 16 miles in circumference; the radius of the circle it forms is equivalent to the length of Central Park. It's 300 feet underground, a depth about the height of the Statue of Liberty. One of four experimental chambers, the Atlas, is approximately the height of the Rose Center. The LHC is designed to collide t wo cou n t er rotating beams of protons or heavy ions in a vacuum, guided by dipole magnets. Some 1,232 superconducting magnets, cooled to just 1.9 degrees above absolute zero, accelerate protons to 99.999999 % of the speed of light. The cables are super-cooled by a huge cryogenics system to conduct current without resistance--a superconducting state. The beams can be maintained at high energy for 10 hours. Each proton completes the loop 11,000 times a second, or 396 million in 10 hours. The first beams are scheduled for May and the first high-energy collisions are anticipated in mid-year. The LHC's size is determined by maximum strength of the magnetic system. To have a smaller circle, the strength of the magnets would have to be much greater to
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bend the beam into a "tighter" circle. Originally, the U. S. planned to build a "superconducting super collider" in Texas three times more powerful than the LHC. However, funding was curtailed by the Clinton Administration and Congress, since they couldn't be satisfied of the project's value and thought there should be significant foreign investment. The U.S. has contributed $500 million to the LHC, 12.5% of the $4 billion cost. The rest is from Europe. LHC's purpose, Arkani-Hamel noted, is to research one of the most persistent mysteries of the universe: why matter has mass at all. Physicists think the answer is a particle called the Higgs boson that's believed to give other particles mass. This theoretical "missing-link" particle and its physics are known as the standard model. The Higgs particle has never been observed in experiments. According to calculations, it exists in detectable form only at extremely high temperatures and pressures similar to those of the first few seconds after the Big Bang. According to Arkani-Hamel, "These reactions happen about 10,000 times a day in the atmosphere, but it takes a machine of this size and power to duplicate these random occurrences in a controlled environment, where they can be observed." Some of this experimental work h a s b een d on e at the Tevatron collider at Fermilab outside Chicago. The LHC will enhance the Higgs search since it's 10 times more powerful than Fermilab. Currently, the Standard Model explains everything detected down to 10-16 centimeters. That is, no experiment contradicts the Standard Model. It's anticipated that the LHC will be able to detect particles down to 10-17 centimeters. According to Arkani-Hamel, "70 years of quantum mechanics gives us the confidence that we'll find the Higgs particle." For most of the ring, the beams travel in two separate vacuum pipes, but at four points they're made to collide in the hearts of the four main experiments. The Collider continued on page 5


Chinese Amateurs Discover Comet with Digital Camera
By Tony Hoffman
In a triumph of astronomy in t h e com p u t er a ge, two Chinese amateurs have discovered a comet in images taken with a digital SLR camera and relayed across China for analysis. Tao Chen detected the comet in images taken by Xing Gao from the Xingming Observatory in northwestern China, as part of a search for novae. At discovery, the comet now named C/2008 ChenGao glowed at magnitude 12 in Cepheus, relatively bright for a comet when discovered. It had presumably been missed by professional asteroid-search surveys because it was moving in a star-rich area of the Milky Way. Asteroid surveys usually avoid such star-dense regions, but they're a perfect place to look for novae, which usually appear in the plane of our galaxy. And a good place, it seems, to serendipitously find a comet. The Xingming Observatory is named for Chinese comet hunter XingMing Zhou, who spent some 1,700 hours scanning the night sky for comets without discovering one that bears his name, but did find 64 comets in SOHO images. XingMing was killed in a driving accident at age 39 on his way home from a scientific conference; I wrote about him in the September 2004 Ey epiece. XingMing, like Xing, lived in Xinjia ng pr ovince. Mt. Nanshan, site of the Xingming Observatory, is south of Gao's home city of Urumqi. The images from the nova survey were sent online to Tao in the city of SuZhou, some 3,000 miles away, where he detected the comet. E-mailing me, T a o wr ot e, "We used this equipment with long-distance control by the network ." I take that to mean that the camera itself is remotely operated, without a human presence onsite, but I'm not certain; there's a language barrier. He did say that they used a Canon 350 (Digital Rebel XT) DSLR with 200mm lens at f/2.8, with a field of view of about 4 by 6 degrees, very similar to the setup I use for astrophotography Tao and Xing are familiar to me, as they've been involved in two online astronomical-discovery projects I've participated in. They both hunt for SOHO comets (Tao has found 10 SOHO comets and Xing 3), as well as the Spacewatch FMO Project, in which Tao found a near -Earth asteroid. Another Chinese amateur, Quanzhi, who was also involved in these projects, found a comet in the night sky as part of the Lulin Sky Survey, although official credit for the discovery went to the Lulin Observatory. Amateur astronomy, both in the night sky and online, has become very popular in China. Most SOHO comets these days are found by Chinese amateurs. Comet Chen-Gao has brightened slightly since discovery, to about magnitude 11.5. Although it may brighten further in the next month or so, it's unlikely to come into easy reach of small scopes or binoculars. But even if I never see it, it will remind me how interconnected amateur astronomers have become globally. Mars continued from page 3 ber "seeing" three or four dots that were part of a pentagram shape at around 120 degrees longitude. I reconstructed what I saw using a French 1939-41 map of the planet, which seem to agree with what I observed.

I'm certain I saw some of the Martian "lakes," Ascraeus Lacus and a dark area Amazonis (near Nix Olympia) in the northern hemisphere. Phoenicis Lacus was the prominent part of the pentagram I recalled seeing. I redrew my sketch of Mars hoping my imagination didn't run wild, feeling confident I finally salvaged something of Mars to remember. --Thomas Haeberle
Collider continued from page 4 experiments use different technologies to detect particles as the energy of colliding protons transforms fleetingly into a variety of exotic particles. The detectors can "see" up to 600 million collision events per second, with experiments scouring the data for signs of extremely rare events such as creation of the much-sought Higgs boson. Answering a question about the facility's safety, Arkani-Hamel conceded that a microscopic "black hole" might be formed, but it would decay almost instantly.

Have you renewed your AAA membership?
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The Five-Millennium Canon of Solar Eclipses
By Thomas Haeberle
The power of a solar eclipse h a s h a d a t r em en dous effect on civilizations around the world. To the ancients, an unexpected eclipse was both awesome and terrifying. Knowledge is power and to be able to predict these events meant having the ability to control the masses. Astronomers were held in high regard in many societies. Their ability to predict certain events was of the utmost importance. It could also mean the difference between life and death. In 2159 B. C., the Chinese emperor put to death the royal astronomer brothers Hi and Ho when they failed to predict an eclipse. As mentioned earlier in Ey epiece, I attended a conference last year on solar eclipses. For me, the highlight was Fred Espenak's talk on his "Five Millennium Canon of Solar Eclipses." Long ago, much was known about eclipses reoccurring, but no one had mapped the actual umbral (dark) shadow track until the 18th century. produced his first "Canon of Solar Eclipses" (1966, coauthored with Vanderleen and Grosjean) for 1898 to 2510. Meeus specializes in celestial mechanics and his more recent works are the popular "Mathematical Astronomy Morsels" series I thru IV. Espenak noted that eclipse calculations were done mainly for historical studies. Inspired by Meeus, he wrote his first software based on his mentor's calculations.

Meeus produced a n ot h er ca t a log in 1983 a n d E spenak published his first canon for 1986 to 2035. Cheerfully, he called it his vacation guide. Maps not only showed the umbral paths as in previous catalogs, but the wider penumbral paths. He and Jay Anderson have also produced NASA eclipse bulletin guides since 1984.
Having always wanting to work with Meeus, Espenak conceived the idea of a canon that would cover 2,000 B. C. to 3,000 A. D., during which the Earth experienced/will experience 11,898 solar eclipses of all types. The 648-page "Five Millennium Canon" includes 20 miniature global maps on 595 plates depicting the umbral (or antumbral) track and penumbral shadow, as well as partial eclipses. This catalog is comprehensive, m a n y t im es m or e detailed and accurate than the Oppolzer maps. Even so, there are uncertainties the more eclipse dates deviate from the present. One reason is that the Earth rotated faster in the past and continues to slow due to the secular acceleration of the Moon, where tidal interactions between the Earth and the Moon slowly force the Moon away from the Earth over time. Also, orbital perturbations within the Earth-Moon system add to the difficulties of calculating the Moon's position, making the effect cumulative yet small. Historical trends are used to amend these discrepancies; even so, the maps should be accurate to within several arc seconds within several centuries to the present. The entire document is available in PDF format (http://sunearth.gsfc.nasa.gov/eclipse/ SEpubs/5MCSE.html), so everyone can download a copy. To learn more about the catalog, contact me at

At around that time t h er e wa s gr ea t excit em en t in the scientific community because the Moon's shadow would crisscross Europe, particularly in England. "Back in the day of Isaac Newton, his colleague Edmund Halley produced the first eclipse maps [1715 and 1724] using pen and paper, a very laborious job," Espenak explained. The maps were exquisite and more would be produced for later eclipses, but there was no catalog of future eclipses until the next century.
The first such catalog was produced in 1887 by Theodor Oppolzer, "The Canon der Finsternisse," a compilation of the 8,000 solar and 5,200 lunar eclipses from 1,207 B.C. to 2,161 A.D., with 160 maps. Once recognized as a great computational feat, "these maps were not as accurate as a modern map done by computers because they used only three positions, sunrise, noontime and sunset, focusing on the umbral path and not the penumbral shadow. He also employed 5 to 10 human computers to do the calculations. The maps, though somewhat accurate, were a guide for researchers to give an idea what geographical area the eclipse traversed.
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Eighty years later, Belgian astronomer Jean Meeus


Review: Case Files from the Cosmic Detective Agency
By Tony Hoffman
The period from t h e la t e 1700s t h r ou gh t h e m id 1800s was a golden age in solar-system-related discoveries. In 1781, William Herschel discovered the first planet other than those known to the ancients (eventually to be named Uranus). Meanwhile, in France, Charles Messier was conducting the first systematic telescopic search for comets, and cataloging fuzzy "comet imposters" to avoid, which today we know as star clusters, galaxies and nebulae. (His list of discards is remembered long after most of the dozen comets whose discovery he was credited with were forgotten.) As the 19th Century dawned, astronomers trying to find a "missing planet" between Mars and Jupiter found much more--and much less--than they bargained for; namely, a host of tiny worldlets we call the asteroids. And in 1846, mathematically minded astronomers, having theorized that perturbations in Uranus' orbit were caused by an unseen outer planet, tracked down Neptune. Yet along with great strides in discovery, there were still vast blank areas on the map, which could have been captioned "here there be dragons." And it seemed that with every advance came some faux pas, misidentification or enigma, a few of which remain unexplained to this day. In "The Haunted Observatory" (Prometheus Books, $28), British astronomer Richard Baum has plumbed astronomical archives to uncover and describe some of these mysteries and oddities, including planets found and lost; lichtflocken ("flakes of light" appearing like passing meteors, observed telescopically in full daylight); brilSearch continued from page 1 other. Tiny arms' laser disturbing the passing changes in test-mass distances throw the two beams out of phase with each other, thereby their interference and revealing the form of gravitational wave. liant objects seen near the Sun that were possible comets, some of them seen by expert observers such as veteran comet discoverer Lewis Swift but never officially confirmed; the "Himalayas" of Venus (although Johann SchrЖter is credited with proving Venus had an extensive atmosphere, the enormous mountain ranges he claimed to have observed proved to be largely illusory); the search for a moon of our own Moon; and the "Coleridge effect," in which Baum provides evidence through observational accounts that the description of a star appearing to hang between the horns of the crescent Moon in Samuel Taylor Coleridge's "The Rime of the Ancient Mariner" may have been more than poetic fancy. The bulk of the mysteries Ba u m d iscu sses a r e from the aforementioned "golden age," but some extend to the mid-20th century. He omits some obvious ones like the illusory Martian canals (which has been discussed extensively elsewhere and could probably take up a book itself). Some sections get a bit dense and wordy; the chapter on "The Himalayas of Venus" is interminable. If the book has a sin, it sometimes gets too detailed, although that's much better than being vapid and uninformative. I did catch an error. Baum describes Halley's Comet as visible in daylight in 1402. There was a daylight comet visible, but it wasn't Halley's, which was seen in 1378 and 1456. But quibbles aside, "The Haunted Observatory" should appeal to anyone interested in the history of astronomy or in astronomical discovery and mysteries. fundamental particle that accompanies these waves) has zero rest mass; and allow study of gravitational waves produced when space and time began. "When LIGO was first built, it was expected that gravitational waves would be detected," Mavalvala said. A new device is p r op osed t o fin d gr a vit a t ion a l waves. This is LISA--Laser Interferometer Space Antenna, proposed to be a widespread instrument than can detect very low-range frequencies that ground-based detectors cannot achieve, by bouncing laser light across vast distances in space. LISA will launch in 2015.
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LIGO will be used for r esea r ch in t o t h e n a t u r e of gravity, and will open up a new window onto the universe. It's believed it will verify directly Einstein's general relativity prediction that gravitational waves exist; test general relativity's prediction that these waves propagate at the same speed as light, and that the graviton (the


Briefs: Multi-Planet System Could Be Like Our Solar System
A multi-planet system p ossib ly lik e ou r sola r syst em has been discovered. A Jupiter-like planet and another about the size of Saturn could mean solar systems like ours are common. The planets appear to be gaseous and are about 80% the sizes of Jupiter and Saturn. Their star is half the size of our Sun, dimmer and much cooler. The solar system, 5,000 light-years away, is more compact than ours. The larger planet's orbit is 2.3 times as far from its star as Earth is from the Sun; Jupiter is 5.2 times farther from the Sun than Earth. The ratio between the masses of the two worlds is about 3:1, similar to the Jupiter/Saturn ratio. The smaller planet is about twice as far from its star as the larger one, as Saturn is roughly twice as far from the Sun as Jupiter. The worlds orbit their star in 5 and 14 years, similar to the 2:5 Jupiter/Saturn ratio. Even though their star emits 5% the light of the Sun, the planets are thought to be about the same temperatures as Jupiter and Saturn because of their tighter orbits. The planets were found using gravitational lensing. Bright hazes t h a t m yst er iou sly a p p ea r a n d d isa p pear on Venus in a matter of days have revealed a new feature of its cloudy atmosphere. ESA images show development of a bright haze over southern latitudes in July 2007. The high-altitude veil continually brightened and dimmed, moving towards equatorial latitudes, then back towards the South Pole. The markings indicate regions where solar ultraviolet radiation is absorbed and reflected by sulfuric-acid particles. Gaseous sulfur dioxide and small amounts of water vapor are usually found below altitudes of 43 miles in Venus' carbon-dioxiderich atmosphere. These molecules are usually shrouded by clouds. Sulfuric-acid particles that make up the bright haze are believed created when some process lifts the gaseous sulfur dioxide and water vapor high above cloud tops where they are exposed to solar UV radiation. The radiation breaks up the molecules, making them highly reactive. Molecule fragments seek each other and combine to form sulfuric-acid particles. What causes sulfur dioxide and water vapor to well up isn't known. Transient dark markings on the images are more baffling. The last total lunar eclipse u n t il 2010 t ook p la ce February 20, with appearances by Saturn and the bright star Regulus on either side of the veiled full Moon. Skywatchers viewing through scopes saw Saturn's rings. The total eclipse was seen from North and South America.
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People in Europe and Africa saw it February 21. Astronomers have glimpsed wh a t m a y b e t h e farthest galaxy we've ever seen, providing a picture of a baby galaxy born soon after the beginning of the universe. Hubble images reveal the galaxy, born about 700 million years after the Big Bang, at almost 13 billion light-years away. The discovery was made possible by a natural magnifying glass, the galaxy cluster Abell 1689, which lies between us and the distant galaxy. Abell 1689's gravity is so strong it bends light that passes near it, acting like a giant zoom lens magnifying what we see. New research reveals t h e seem in gly gen t le t ou ch downs of the six Apollo Lunar Modules on the Moon between 1969 and 1972 were actually violent. The Lunar Module's descent engine blew out high-velocity lunar particles. Apollo astronauts saw the smallest particles fly over the horizon and keep on going. Depending on velocity, they may have gone halfway around the Moon or more. Minute specks of lunar dust may have been propelled at speeds up to 5,400 mph, nearly fast enough to escape the Moon's gravity and enter orbit around the Sun. Engine gas blasts move rocks up to 6 inches in size. The first triple asteroid n ea r E a r t h h a s b een d iscovered just 7 million miles away. It was originally found in 2001, but new observations reveal it's three gravitationally bound rocks. The main rock is spherical and about 1.5 miles wide. Another is about half that size. The smallest is about 1,000 feet across. The towering 3-D features of M a r t ia n ca n yon s and highlands are about to stand out like never before, thanks to a high-resolution camera on the Mars Express orbiter. Data allow scientists to create models to look around the surface from different directions and angles. Creating the data for such digital models requires spacecraft to study the same Martian feature at least twice, each time from a different angle. Most previous efforts have involved spacecraft making two orbital passes over features. Two old stars a p p ea r t o b e gea r in g u p for a second generation of planet formation, a phenomenon not Continued on page 9


Briefs: Probe May Answer Questions About Mercury
Continued from page 8 seen before. The exact ages of BP Piscium in Pisces and TYCHO 4144 329 2 in Ursa Major are unknown, but they might have given birth to planets long ago. How they do this again is unclear. Orbiting disks of gas and dust extended around the stars, and, with BP Piscium, jets of gas eject into space. The stars might borrow material from their neighbors to build new worlds. Explosions of small stars, lon g t h ou gh t t o cr ea t e stellar dust, actually sweep dust away. For years, researchers have observed swirling dust clouds around socalled recurring novas, which periodically explode. New images of a distant nova have overturned astronomers' long-standing assumption the dust originates in the blasts. Scientists recently observed the RS Ophiuchi system, where a small white dwarf and large red giant orbit each other. Over time, the giant sheds its outer layer of gas, which the dwarf sweeps up. For the first time in 33 years, a sp a ce p r ob e zoomed by Mercury. MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) skimmed 124 miles above during the first of three flybys prior to 2011 orbit. Researchers hope MESSENGER will answer questions on Mercury's high density, magnetic field and thin atmosphere. The probe will spend a year in orbit. Scientists anticipate views of Caloris Basin, a large impact crater. A sunshade allows the probe to keep its instruments about room temperature while the Sunfacing side reaches 600 degrees. Pictures include "the spider," an apparent impact crater surrounded by more than 50 cracks in the surface radiating from its center. . A young star sp eed in g a wa y fr om t h e M ilk y W a y is an alien visitor. The object is one of several rogues giving astronomers a glimpse into the volatile nature of our galaxy and others. Astronomers have found 10 stars hurtling from our galaxy at speeds exceeding its gravitational grasp. Most are thought to be exiles from the center of our galaxy, flung into intergalactic space by the massive black hole at the center of the Milky Way. A recycled comet-smashing probe h a s b egu n a new mission to seek alien worlds beyond our solar system. The surviving mother ship of Deep Impact is aiming its largest telescope at five stars to catch a glimpse at any planets they may harbor. Deep Impact trained the scope on its first target January 22 to look for dips in the stars ' light. Each star is known to host massive, close-orbiting planets the size of Jupiter or larger. In addition to the planet hunt, the spacecraft is headed to Comet Hartley 2 to map gas outbursts and search for water ice. An asteroid once thought t o b e on a collision course with Mars passed the Red Planet January 30 without incident, missing Mars by about 6.5 Mars radii. This occurred a day after a 500-foot asteroid flew by Earth at 334,000 miles. The lopsided Mars rock, an estimated 800 feet in diameter, was visible January 29 to amateur astronomers with modest-sized telescopes. At its nearest, the asteroid reached apparent magnitude 10.3, 50 times fainter than an object visible to the naked eye. A distant galaxy cluster h a s t u r n ed in t o a gia n t particle accelerator, spinning electrons over vast distances at high speeds. Scientists discovered the phenomenon by observing highly energetic X-rays emanating from the Ophiuchus cluster. The ESA's orbiting gamma-ray observatory Integral detected the X-rays, which are too energetic to originate from the inert gas in the cluster and must instead come from accelerated particles. This is the first time significant high-energy X-ray radiation from a cluster has been detected. Dinosaur doomsday wa s wet t er t h a n scien t ist s thought, according to new images of the crater where the asteroid that likely killed the reptiles landed. Sixty-five million years ago the rock struck the Yucatan, and most scientists think this played a large role in extinction of 7% of life on Earth. The most detailed 3-D seismic images of the mostly submerged Chicxulub crater show the asteroid landed in deeper water than assumed, releasing 6.5 times more water vapor into the atmosphere. Images also show the crater contained sulfur-rich sediments that would have reacted with water vapor to create sulfate aerosols. These compounds would have made the impact deadlier by cooling the climate and producing acid rain. After more than 50 years a t t h e papal summer palace in Castel Gandolfo near Rome, Vatican astronomers Continued on page 10
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Briefs: Mysterious Source of Antimatter Discovered
Continued from page 9 will move to bigger, more modern facilities. The Jesuit astronomers' offices and residences will remain on the residence grounds, but in a renovated convent in the papal gardens. Work hasn't begun on the new headquarters, so the relocation is unlikely before fall. Needs of papal quarters aren't easily combined with a residence for Jesuits engaged in study, teaching and research. New discoveries in a st r a n ge sp ir a l ga la xy sh ow it has a pair of arms winding backward compared to the typical direction for most galaxies. Most spiral arms observed tend to trail in the wake of their galaxy's spin, meaning they wind in the direction opposite the rotation. The strange galaxy, NGC4622, lies 200 million lightyears away and has a large outer arm pair that winds clockwise. Scientists analyzed a 2001 Hubble image of the galaxy and found a previously hidden inner pair of arms winding counter-clockwise. The mysterious source of a n t im a t t er , wh ich a n n ihilates matter upon contact, has been discovered: stars getting ripped apart by neutron stars and black holes. As a black hole or neutron star destroys a star, tremendous amounts of radiation are released. Just as electrons and positrons emit the tell-tale gamma rays upon annihilation, so can gamma rays combine to form electrons and positrons, providing the mechanism for the creation of the antimatter cloud. A relatively ordinary star getting torn apart by a black hole or neutron star orbiting around it could spew on the order of one hundred thousand billion billion billion billion positrons per second. These could account for a great deal of antimatter that scientists have inferred, reducing or eliminating the need for such explanations as those involving dark matter. Astronomers have found t h e fir st sign a t u r e of complex organic molecules in the dust cloud around a distant star, suggesting the building blocks of life may be common in planetary systems. In our solar system, large carbon molecules, tholins, have been found in comets and on Titan. Tholins are thought to be precursors to biomolecules making up living organisms on Earth. Observations of the spectrum of the dust disk surrounding star HR4796A indicate the presence of tholins. The spectrum of scattered visible and infrared light from the disk looks
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very red, a color known to be produced by tholins. HR4796A, in Centaurus, is an 8 million-year-old star 220 light-years away. An experiment to simulate st r esses of a m a n n ed mission to Mars on humans could cost more than $15 million, Russian wire reports say. The estimate came after a two-week test run using a mock-Mars habitat built in Moscow. The long experiment is expected to simulate the 40-minute delay in communications between Earth and Mars, and feature mock explorations of the surface. As white dwarfs form, t h ey get a k ick t h a t p r opels them to thousands of miles per hour, Hubble evidence shows. Astronomers looked at distribution of white dwarfs in the ancient globular cluster NGC 6397. Because its stars were very massive before burning out as white dwarfs, and massive stars tend to gather at the cluster's core, astronomers assumed most new white dwarfs would dwell at NGC 6397's center. But they discovered young white dwarfs at the edge of the cluster. The Ulysses spacecraft flew over t h e Su n ' s Nor t h Pole January 14, a week after physicists announced the beginning of a new solar cycle. Ulysses can fly over the Sun's poles and look at regions hard to see from Earth. Researchers term the Sun's poles central to the ebb and flow of the solar cycle. When sunspots break up, their decaying magnetic fields are carried toward the poles by vast plasma currents. During the most recent solar cycle, the North Pole was about 80,000 degrees, 8% cooler than the South Pole. Meanwhile, Ulysses, after 17 years of studying the Sun and solar system, is about to die by freezing. The satellite long outlasted the five-year mission begun in 1990, but continued to transmit data on solar winds. More recently, its plutonium power source slowly weakened and its fuel was freezing as it made a wide circle of the Sun, traveling as far as Jupiter. The $250 million probe is a joint European-NASA project. Scientists have detected t h e lowest fr eq u en cy r a dar echo off the Moon ever picked up by Earth-based receivers. In the experiment, high-power radio waves were sent toward the Moon. The signals, weakened by the journey to the Moon and back, were detected 2.4 secContinued on page 12


Events on the Horizon March 2008
M: members; P: open to the public; T: bring your telescopes, binoculars, etc.; C: cancelled if cloudy; HQ: at AAA headquarters, 1010 Park Avenue (between 84th and 85th streets); AMNH: For ticket information, call (212) 769-5200 Thursday, March 6, 6:30 p. m. Recent Advances in Astronomy Seminar, M, HQ Note date change. Next da te: Apr il 10. Friday, March 7, 6:15 p. m. AAA lecture, P Speaker undetermined at presstime. Please check www.aaa.org for updated information. Saturday, March 8, dusk Stargazing, Great Kills, Staten Island, P, T, C Next date: April 12. Thursday, March 13, 7:30 p. m. Annual Isaac Asimov Panel, P, AMNH Planets, moons, asteroids and comets contain natural resources such as water, minerals and trace elements that may have survival value to astronauts and economic value to life on Earth. How did we learn of these materials? How would one mine them? Who owns these resources, if anyone? Should they be mined at all? A panel will have experts in planetary science, aerospace engineering, environmental engineering and space law. Friday, March 14, 8 to 10 p. m. Observing at Floyd Bennett Field, Brooklyn, P, T, C Model airplane flying field. Next date: April 11. Monday, March 24, 7:30 p. m. Hayden Planetarium Lecture, P, AMNH In "From the Big Bang to the James Webb Space Telescope," John Mather, who won the Nobel Prize in physics in 2006, describes his role in developing NASA's Cosmic Background Explorer satellite, which helped confirm the Big Bang theory. He also discusses plans for the next great space telescope, the James Webb Space Telescope, scheduled for launch in 2013. Saturday, March 29, 1 to 4 p. m. Observers Group, M, HQ Next date: April 26. Saturday, March 29, 10 a. m. to noon Central Park solar observing, P, C At the Conservatory Waters. Next date: April 26. NOTE: Cadman Plaza, Brooklyn, observing resumes April 8 and Carl Schurz Park, Manhattan, April 25. Fedrick continued from page 2 over several mornings until, on the morning of January 31, Jupiter was only about one degree to the lower left of Venus. Venus shone near magnitude 4 while Jupiter was approximately two magnitudes fainter. I observed Jupiter and Venus only without optical aid. Jupiter was still very near the horizon in bright twilight and likely unfavorable for telescopic observation. Mars still shone brightly d u r in g J a n u a r y. I ob served the large dark gray triangular region Syrtis Major as it contrasted with adjacent coral pink areas. I saw it using my 60mm refractor at 100x on January 23 and 25 from 6 to 7:30 p. m. In February, Mars began to fade noticeably as the distance between Earth and Mars began to increase. The Martian disk appeared slightly smaller telescopically and the disk appeared slightly gibbous. Observation of the surface features on Mars was becoming more challenging. The season for observing Mars was coming to a close.
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Contacting the AAA
If you want to join, volunteer, participate in events, have a question or change your address, e-mail members @aaa.org, or leave a message at AAA hq: (212) 5352922. Also, visit us on the web at www.aaa.org. If you're interested in writing for Ey epiece, contact editor Dan Harrison at editor@aaa.org or (914) 762-0358.


Briefs continued from page 10 onds later. The transmitter sent out two-second pulses every five seconds for two hours each day of the two-day study period, one hour for each frequency at which it operated. The echo signals at 7.4075 megahertz, made by the pulse bouncing off the Moon, are believed the lowest frequency at which these radar measurements have been conducted. The experiment reveals more about the Moon's structure. Meade Instruments set t led a com p la in t b y St a r Instruments and RC Optical Systems against the company and its dealers. Plaintiffs dropped their claim for substantial monetary recovery. Meade also agreed to rename its RCX product, not using any initials that might suggest Ritchey-Chretien in the name. Meade will be under no restrictions in referencing the Ritchey-Chretien-like benefits of the RCX product, such as the elimination of coma, which many term the single largest benefit of the Ritchey-Chretien optical system. A movement to immortalize fa m ed C or n ell a stronomer Carl Sagan with a postage stamp was launched at the Ithaca, N.Y., Sciencenter. Four renderings by three artists or artist teams of proposed Sagan memorial stamps were unveiled. The Sagan Appreciation Society will submit them to the Postal Service. NASA is asking t h e p u b lic t o su ggest a n ew name for the Gamma-ray Large Area Space Telescope, GLAST, before it launches in mid-2008. GLAST will probe the most violent events and exotic objects in the cosmos from gamma-ray bursts to black holes and beyond. Details: http://science.nasa.gov/headlines/ y2008/08feb.namethattelescope.htm?list075395. Robert Jastrow, t h e r en own ed sp a ce p op u la r izer who headed NASA's Goddard Institute for Space Studies in New York for 20 years and earlier ran NASA's theoretical division, died at 82. After Goddard, Jastrow headed the Mount Wilson Institute and the George C. Marshall Institute, a science- policy organization. Five University of Washington st u d en t s com b in g through telescope images found more than 1,300 previously undetected asteroids. They make up one in 250 known objects in the solar system, but none is known to be an immediate threat to Earth. The students set out to find supernovae but the asteroids blocked their view.

Correction
An article in last month's issue on a Hayden lecture on dark energy misspelled the name of the speaker. It's Adam Riess, not Reiss.

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