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Journal of the Amateur Astronomers Association of New York May 2008 Volume 56 Number 5, ISSN 0146-7662

EYEPIECE
-priority Hubble Space Telescope.

Nobel Laureate Outlines Work on COBE, Webb Telescope
By Edward J. Fox
A boy of eight, fr om r u r a l New J er sey, visit s t h e Hayden Planetarium with his family, piquing his interest in cosmology. Some five decades later, on March 24, 2008, he returns as Dr. John C. Mather, Nobel Laureate...a guest lecturer, describing his key role in analyzing data from NASA's Cosmic Background Explorer (COBE). The COBE team had imaged primordial hot and cold spots in the cosmic background radiation. Mather had been awarded the Nobel Prize in Physics in 2006, along with his associate, George F. Smoot, for imaging and understanding evidence of the Big Bang. As Mather described the process, his was certainly not an overnight success. But it was the culmination of a great career in cosmology. In fact, Mather had been a key participant in developing the project out of his doctoral work to prove the theories of the Big Bang. However, according to Mather, "because of Murphy's Law and the limited scope of the balloon-launched project within Earth's atmosphere, the project wasn't a success" by the time he published his doctoral thesis. His thesis was limited to describing ground-based work and design of the balloon-raised instrument to measure the cosmic background against theoretical calculations. Mather's associate, David Woody, "found out why the instrument had failed, fixed it and made it work right for the second flight, the summer after I left Berkeley for New York."
When NASA, in 1974, ca lled for p r op osa ls for Scout and Delta-launched satellite missions, Mather recognized "that [the] thesis experiment would have worked a lot better in space." He and his associates developed a proposal, which was selected by NASA. The project got underway in earnest at the time the shuttle program was in development and it was initially planned for the satellite telescope to be sized to be launched by the Shuttle. The project was developed at the same time as the higher

The project's design and construction p r ocess was developed in-house, since scientists didn't want an outside company to design and build something that had never been done before. Almost two decades after its inception, the COBE team announced in 1992 it had mapped the cosmic background radiation. At the time the imaging of temperature variations was announced, Stephen Hawking called the discovery of temperature variations in the afterglow of the Big Bang "the most important discovery of the century, if not of all time." The project imaged temperature variations of the cosmic background, which were expected to have a temperature about 5 Kelvin (near absolute zero). COBE imaged an area of some seven degrees of arc, an area the size of a fist held at arms length. It was determined that the background temperature is approximately 2.725 K. The COBE team showed that Big Bang radiation has a blackbody spectrum within 50 parts per million that agrees with theoretical predictions with extraordinary accuracy. It confirmed the Big Bang theory and showed that the Big Bang was complete in the first three minutes, with only a tiny fraction of energy released later. Not one to rest on his laurels, M a t h er d escr ib ed his work as senior project scientist and chair of the Science Working Group of the upcoming James Webb Nobel continued on page 5

REMINDER--The AAA's annual meeting is May 21. Dinner is 6:30. The meeting begins at 7:30. See page 11 for details. Come and be with your fellow members!


What's Up
By Tony Hoffman The Sky for May 2008
Eta Aquarid Meteors to Dazzle? Alt h ou gh t h e Eta Aquarid meteor shower is one of the more prolific showers, averaging some 30 meteors an hour from a dark -sky site where the radiant is high, it's tricky to see from mid-northern latitudes, as Aquarius doesn't rise until the predawn hours and is low in the southeast as morning twilight begins to interfere. The Eta Aquarids are composed of debris from Halley's Comet, which last passed "near" us in 1986. The meteors are believed to vary in a 12-year cycle (possibly influenced by Jupiter, which circles the Sun in 12 years), and this year they should be near their peak. If we're lucky, we could see double the shower's average rate. Planetary Bonanza. A wea lt h of p la n et s gr eet s ob servers this month, no matter what time of night you look up. Elusive Mercury puts on its best evening showing of the year in the first three weeks of May. It 's highest in the sky in the second and third week and at its absolute highest on May 13. It starts the month at magni-

tude -0.9, and by midmonth fades to 0.4. Mars hangs on in the west in Gemini, shining at magnitude 1, about the same as nearby Pollux. Between May 21 and May 23, the Red Planet crosses the Praesape (Beehive) star cluster. It will outshine the cluster's brightest members magnitudes. Meanwhile, Saturn spends the month within 3 degrees of Regulus in Leo. At magnitude 0.6, Saturn is the brighter of the pair. The ring system is closing; by the end of the year it'll be nearly edge-on, so enjoy the views while you can. And if you stay up late or get up early, Jupiter is a dazzling sight in Sagittarius. By month's end, Jupiter will blaze at magnitude -2.6 and rise before midnight. May 5 New Moon at 8:18 a.m.; Moon at perigee, 222,309 miles from Earth, 1:18 p.m.; Eta Aquarid meteor shower peaks. May 6 Moon lies near Mercury. May 10 Mercury lies near Aldebaran and Mars. May 11 First-quarter Moon at 11:47 p.m. May 12 Moon lies near Regulus and Saturn. May 13 Mercury at greatest elongation in evening sky. May 19 Full Moon at 10:11 p.m. May 20 Moon lies near Antares. May 24 Moon lies near Jupiter. May 27 Last-quarter Moon at 10:57 p.m. Mercury disappeared in t o t h e sola r gla r e in March on its way to a favorable evening apparition in late April and May. These quick appearances, disappearances and reappearances were like the swift movements of the messenger of the gods. They reminded me of NASA's mission to Mercury which has transmitted pictures revealing bright craters and has given us a view of parts of Mercury not seen when Pioneer visited during

Mercury, Messenger of the Gods
By Joseph A. Fedrick
I observed Mercury on J a n u a r y 21 wh en brightly in the southwest after sunset. It was an aided-eye object and shone a creamy white. contrasted nicely with the slightly bluish-white Fomalhaut some 30 degrees to its southeast. it sh on e easy unIts color color of

AAA Nominating Committee's Picks
The AAA nominating committee last month recommended six members for election to the board of directors at the May 21 annual meeting. Vice president-urban observing chair Rik Davis, treasurer Thomas Haeberle, Bruce Kamiat and former president Michael O'Gara were endorsed for new three-year terms. Edward J. Fox, named to the board last year, was also recommended. Shana Tribiano, who teaches astronomy at Borough of Manhattan Community College, would be a new board member. The nominating committee consisted of Dan Harrison(chair), Marcel Cabrera and Terrell Kent Holmes.

Mercury quickly disappeared from the evening sky as January closed. It quickly rose from the solar glare into the morning sky so that by February 28 and 29, I saw it just a few degrees from the much brighter Venus. I saw Mercury approximately 2 degrees to the upper right of Venus on March 2 and 3 in my 10x 50 binoculars and would have observed it deeper into March, but was hampered by frequently cloudy skies and by the fact that the ecliptic was making an unfavorable shallow angle with the eastern horizon. Morning objects near the eastern horizon are easier to see in the autumn when the ecliptic makes a favorable steep angle with the eastern horizon.
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A Message from AAA President Richard Rosenberg
Hello, members: May is an exciting month for the club. Besides our annual meeting, we'll have a special observing session and our first club event at New York University. Thursday, May 8 begins a new era for the AAA. Thanks to the generosity ment of physics and in particular Prof. David Hogg, our Recent Advances in campus. We'll have access to up-to-date information via the Internet and will movies. A planetarium program downloaded onto our new club laptop will illust of NYU and the efforts of the departAstronomy Seminar will meet on the be able to view diagrams, charts and rate upcoming celestial events.

The seminar will take place from 6:30 to 8:30 p. m. in Room 405 of Kimmel Center, at 60 Washington Square South, on the corner of LaGuardia Place, near several subway lines. Bring ID and tell the guard you 're attending the seminar. If you have questions or need more specific directions, contact me. We hope soon to move the Observers ' Group meeting and eventually all our indoor events to NYU. All NYU personnel--students, faculty and staff--will be able to attend our events. I hope that our relationship with NYU's physics department will expand to enable AAA members to assist on research projects and help operate telescopes for astronomy classes.
On Saturday, May 10, the AAA will join the Riverside Park Fund in an observing session at Riverside Park at 96 Street. We'll begin at 7 p. m. by looking at the crescent Moon. As the sky darkens we 'll see the Beehive Cluster and watch the Moon occult a few members of the cluster. In addition, Mercury should be easily visible in early evening. Mars will not be far from the Moon and Saturn similarly close to the star Regulus. Throw in a few deep -sky objects and we should have a great time. Parking is available. Check the map on our website or contact me for directions. Our annual meeting is on Wednesday, May 21 at headquarters, 1010 Park Avenue. A buffet dinner at 6:30 will be followed by the meeting at 7:30. Find out what's happening with the club, elect members to the board of directors, honor Amateur Astronomers Medal recipients Eddie Oravec and Bob Little, as well as longtime member Marion McMorris, and hear a tribute to the late Fred Hess. Rich Rosenberg, AAA President, pr esident @a a a .or g, (718) 522-5014

Global Warming To be Discussed at May 2 AAA Lecture
David Helfand, p r ofessor of a st r on om y a n d ch a ir of the astronomy department at Columbia University, will close out the 2007-08 AAA lecture when he discusses "Global Climate Change: What We Know and What We Don't Know" on Friday, May 2. The free public lecture is at 6:15 p. m. in the Kaufmann Theater of the AMNH. "I will attempt a dispassionate analysis of what we know and what we don't know about climate change, clearly distinguishing facts from fictions, and physical certainties from feedback uncertainties. "I will explore a st r on om ica l fa ct or s t h a t d r ove change in the past, and describe how past measurements of climate help inform models for predictions of the future. I will then analyze our current knowledge." Helfand's been at Columbia since 1977 and is on his second tour as astronomy chair. His work has covered m a n y a r ea s of a st r op h ysics including radio, optical and X-ray observations of celestial sources ranging from nearby stars to the most distant quasars. He's now involved with a major project to survey our galaxy with a sensitivity and angular resolution 100 times greater than currently available. The goal is obtain a complete picture of star birth and death in the 3 Milky Way.


Einstein@home Wants You (Actually, Your Computer)
By Tony Hoffman
First there was SETI@Home, in wh ich t h e SE T I Institute enlisted thousands of global volunteers to use some of its computers' unused resources to crunch the enormous amount of data its radio telescope was gathering in hopes of detecting signals from alien civilizations. Now there's Einstein@home. Using the same "distributed computing" model, which numerous other scientific projects have adopted, it seeks to detect elusive gravitational waves, exceedingly faint ripples in spacetime caused by interaction of massive objects in space. Dr. Eric Myers, a scientist with the Laser Interferometer Gravitational-wave Observatory (LIGO), discussed "Einstein@Home: Searching for Ripples in Space -Time with your Home Computer," in his AAA lecture at the AMNH April 11. Large masses in close proximity, like two neutron stars in orbit around each other, should cause space-time to be disturbed, and gravitational waves to ripple outward across the universe. Indeed, in 1974, Joseph Taylor and Russell Hulse found a pair of neutron stars (one a pulsar) orbiting each other, and by measuring the gradual slowdown in the pulsar's radio pulses, they concluded that the loss of energy (presumably emitted in gravitational waves) was just as General Relativity predicted. Measuring gravity waves directly is a fa r t r ick ier proposition, as movements in matter caused by gravitational waves are minuscule (as small as one onethousandth of the diameter of a proton). LIGO uses a laser interferometer, in which a beam of laser light is split, allowed to travel along the two "arms" of the interferometer and later recombined. Any minute differences in the lengths of the arms, such as would occur when the interferometer is "rung" by a gravity wave, will cause the beams to become slightly out of phase when recombined, enough for scientists to measure. Other events such as earthquakes can also cause such discrepancies, but by using widely spaced interferometers near Hanford, Wash., and Louisiana, LIGO can distinguish local events or false detections from gravitational waves. Possible sources of gravitational waves include a proposed "gravitational background radiation" similar to background radiation left over from the Big Bang, cataclys4

mic events such as supernovas, the interaction or collision of neutron stars, pulsars or black holes, and even asymmetries in spinning pulsars. To analyze the immense amount of data the interferometers produce, LIGO is relying on public participation through Einstein@Home. It uses the same software as SETI@home, which volunteers install on their computers. Since the program is modular, it can form the core of numerous similar distributed computing projects. Once software is installed, participants receive parcels of data for their computers to process. Processed data are returned to LIGO and a new work unit supplied. A LIGO upgrade sh ou ld b e com p let ed b y t h e en d of next year. Meanwhile, it has a backlog of data. As of the lecture, some 7 million work units in the current run, about 46% of the total, have been processed in 195 days. Einstein@home is looking for a few good geeks with computer time to spare to help finish it off. Already, some 200,000 people have installed the software and let it process at least one work unit. People interested in volunteering should visit http://Einstein.phys.uwm.edu. Gravitational waves have never been directly detected. Thanks to LIGO and Einstein@Home, that may soon change.

IDA Sets Up NY Section
The International Dark Sky Association (IDA) has established a New York State section and website (www.nvida.org) to provide additional information to New York IDA members and the public about light pollution. The section will collaborate with groups concerned with the issue. Section leader is Susan Harder, a 10-year dark-sky advocate active in the group Sensible and Efficient Lighting to Enhance the Nighttime Environment (SELENE). She's won IDA executive director dark-sky awards for her efforts to have outdoor lighting regs enacted in New York and for helping establish New York's first dark-sky park in Montauk. The website provides resources and links to help New Yorkers educate their communities about light pollution.


Anti-Occultations and Other Anti-Climactic Events
By Thomas Haeberle
This month and next, we' ll h a ve som e ver y u n u sual celestial events which you may want to view. A somewhat uncommon event occurs the night of May 21-22, when Jupiter has no moons. To some, this may be as exciting as seeing Saturn with no rings or a penumbral eclipse of the Moon. This event is seen maybe every 7-10 years (or longer) on average, if you're on the Earth's observable side. Just before midnight, shortly after Jupiter's rising, one Jovian moon is occulted, one is in transit and the other two are eclipsed. Unfortunately, Jupiter is only two degrees above the horizon and the event lasts 19 minutes. Next year promises a better prospect of viewing the same event longer, in its entirety and higher in the sky. Four years ago, New Yorkers saw a r a r e t r a n sit of Venus across the Sun. Though it happens again in four years, these paired events come about over a century's time. But another kind of transit, an occultation of Venus by the Sun or an anti-transit of Venus, happens more frequently. The reason for this regularity is the plane of the solar system narrowing when planets on the other side of the Sun journey towards superior conjunction. The date for this year's event is June 9, followed regularly at eight-year intervals until 2048. Thanks in part to our super surveillance of the Sun by the space probe known as SOHO, all you need to do is access the Internet. By using the SOHO link--http:// sohowww.nascom.nasa.gov/--you'll have a ringside seat. I've enjoyed seeing Jupiter and Mercury swing by the Sun (though they were occulted) through SOHO's C2 and C3 cameras. This method is used by Tony Hoffman, who's found more than 100 Sun-grazing comets. Finally, the big event will b e sigh t in g t h e you n gest crescent Moon possible. On the evening of May 5, there will be a rare opportunity to see an 11Ѕ-hour-old Moon, nearly at the limits of the youngest you can see. In the past few years in its February issue, S k y and T elescope ha s listed wher e such young moons could be seen. Naturally, it would be a tremendous occasion if one were to sight this very slender Moon through a scope. Unfortunately, for most it may be a big letdown, but hopefully the fun is in the hunt. Currently a group of Iranian amateur astronomers holds the record, so here's a chance for America to grab the glory. Nobel continued from page 1 Space Telescope (JWST). He called JWST an infraredoptimized telescope cooled to a few degrees above absolute zero. It will be a NASA/European/Canadian project. To be launched in 2013, J W ST will b e p u t in t o orbit of the Sun at Lagrange Point 2, one of five points where the gravitational influence of Sun and Earth are in balance. It will unfold a segmented primary mirror, to be adjusted to shape in orbit. JWST will feature ultralightweight beryllium optics, detectors capable of recording extremely weak signals, microshutters that enable programmable object selection for its spectrograph and a cryocooler to cool mid-infrared detectors to 7 K. JWST will aim to examine every phase of the history of the universe, including the first luminous glows after the Big Bang, formation of solar systems capable of supporting life on planets similar to the Earth and evolution of our solar system. JWST, the premier space observatory, will expand on discoveries of its predecessors. JWST will study first-light objects--stars that finished their lives as supernovae. It will observe millions of galaxies to understand galaxy formation. JWST will observe dust clouds in infrared to study stellar nurseries. It will study the planetary footprints of other stars for exoplanets and their atmospheres, including detection of elements that may be in the atmospheres. It may be capa-

Tyson Gets AAAS Award
Hayden Planetarium director Neil d eG r a sse T yson has won the 2007 American Association for the Advancement of Science Public Understanding of Science and Technology Award. He was cited for his passionate commitment, sustained excellence and dynamic leadership in engaging the public in the frontiers of science.

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Heading to Arizona to Observe Equipment Atop Mt. Graham
By Joe Di Napoli
The article in February's E y ep iece a b ou t t h e Large Binocular Telescope prompted me to write an article about my November tour of the observatories on Mt. Graham, Ariz. I've been a frequent guest of former Staten Islanders Susan Andersen and John Messina at their Sonoita, Ariz., home and observatory. This is where I've taken many astro photos posted in the gallery section of our club's website. In fact, they allow me to store one of my refractors and the very large Titan mount there. It would cost more than $1,000 to ship everything back and forth every time I visit. The day of our tour, John, I and another amateur headed out at 6 a. m. for a two-hour drive to Safford, Ariz. At the visitors center we saw a movie, actually the episode of Really Big Things, about the LBT. We then boarded a van with seven other people plus our guide for a 1 1/2-hour drive to the top of Mt. Graham. I wouldn't recommend this for people who get motion sickness. We first toured the Submillimeter Radio Telescope. The radio scope works around the clock. Luckily, there was an astronomer in the control room taking a reading from a star while we were there. We asked him questions, and he was patient and clear in his responses. The tour took us up to the Nasmyth focus and we were shown how different instruments were exchanged. We also went to the base of t h e m a in r eflect or . While there, we noticed black material that looked like melted plastic on the dish. It seems the scope was pointed too close to the Sun and part of it was melted onto the reflector. I was amazed. My 12-year-old LX200 has software that keeps it away from the Sun, but this "professional" scope obviously didn't. We next went to the Vatican's 1.8m Cassegrain scope. Accommodations for the astronomers were very nice; there was a groggy one going over his previous night's work. We were allowed very close to the scope but it was parked upright and we couldn't see the mirror. The CCD detector and dewar were enormous. We took a short walk to the LBT. You can plainly see how close the recent fire came to this enormous, ex6

pensive telescope. Roughly 200 feet! In the main building, we saw the incredibly large garage area. We could see the oversized tools, hooks and shackles used in moving mirrors and mounting assembly parts. Also visible is the re-aluminizing chamber. After lunch, LBT director Richard Green answered questions. Some non-amateur astronomers asked a few things to get the ball rolling. The tour continued to the mechanisms that turn the whole building. They were similar to huge train wheels. We then went to the main floor of t h e L BT . Most tours aren't allowed here, but for some reason we were. An ordinary tour would have ended, viewing the LBT from a glass-enclosed room behind the scope, and the mirrors would remain out of sight. We were allowed to walk all around the scope and right up to the drive motors. The mirrors were pointed horizontal and were 40 feet overhead. I could see how future instruments would be interchanged at the secondary mirrors. There were ports and cages for multiple instruments. Some structural tubing is air-conditioned to keep everything at ambient temperature. The whole structure is enormous and couldn't even fit in my 38mm camera lens. We were allowed to stay for more than half an hour walking all around the floor. The LBT can be viewed in real time from its website: http://medusa.as.arizona.edu/lbto/live_views.htm. You should reserve a tour far in advance.

Custer Gets Research Grant
The Fund for grant for received Custer Institute, Sou t h old , N. Y., r eceived a Astrophysical Research Theodore Dunham, Jr. astronomy research, the first grant Custer has for its new research program.

The $2,888 grant will be used to purchase optical equipment to search for extrasolar planets and supernovae, the study of properties of stars similar to our Sun and a variety of other research. Custer is concurrently establishing an internship program to give high school students hands-on experience and mentoring from researchers.


Review: Spitzer, the Last of the Great Observatories
By Edward J. Fox
Most amateur astronomers h a ve n o id ea of t h e time and complex collaboration required to develop a major astronomical research platform. George H. Rieke chronicles the infrared Spitzer Space Telescope developed in NASA's era of "faster, better, cheaper" projects in "The Last of the Great Observatories" (University of Arizona Press, $40 cloth, $19.95 paper). Spitzer was originally known as the Space Infrared Telescope Facility (SIRTF). NASA announced plans to accept proposals on Friday, May 13, 1983. The irony of the date was noted by Rieke, who assembled a team to write a proposal, which was delivered in November. He "wanted to do something really noteworthy, as an infrared astronomer." At the time he had hoped to "finish with the SIRTF soon enough to expand on the experience with some future mission." Little did he know that this project would consume so much of his and his collaborators' careers. The proposal was selected for ver y lim it ed NASA funding seven months later. The overall project included, in addition to the far infrared imager, near- and midrange infrared imagers and a spectrograph. Each of these components had a team of astronomers. There were 4550 members of the team, "a significant fraction of the American infrared astronomical community." The mission was conceived to operate a telescope in an environment cold enough not to drown out the infrared signals of subjects under study with infrared or heat of its own. It was to measure infrared radiation in wavelengths from 3 to 200 microns. This would facilitate study of cool objects, such as planets that emit mostly in the infrared, and is the range for the study of cool states of matter, such as solids and molecules. Infrared instruments facilitate the study of dusty regions where visible light is scattered or absorbed. This array of instruments allows the study of very distant objects, where the cosmic redshift causes visible light to appear in the infrared. Acceptance of the original proposal wa s on ly t h e start of 20 years of meetings and presentations to NASA, including many that had nothing to do directly with SIRTIF, but affected NASA policies and funding. One of the most publicized NASA setbacks was the Hubble's initial optics imperfections in 1990. Another was the 1993 Mars Observer, which disappeared with an attempted small correction in its trajectory toward the planet. These and others, on top of the Challenger disaster, eventually led to a drastic cutback in SIRTIF's budget in 1993. What had originally been projected to be in the $2.5 billion range was cost capped at $500 million.

Faced with this challenge, t h e t ea m ch a n ged t h e concept to a "warm" launch. Physics of the infrared require instruments be cooled to just above absolute zero. It had been intended they be launched cold. As on previous infrared missions, the telescope was to have been launched in a dewar--a helium thermos flask--and cooled with the other instruments. A warm launch meant the scope would be at ambient temperature outside the dewar. The scope's radiant energy would be radiated into space during the month after launch. This reduced liquid helium needed for the last cooling stage. A further reduction was aided by a prior decision to have the SIRTF launched into an orbit circling the Sun, rather than Earth. It would trail Earth at a distance adequate to reduce effects of Earth's radiant energy on the instrumentation.
Budget constraints and the limited amount of liquid helium for cooling forced the teams to strictly define the science programs that would be addressed. Four major areas of research were selected: brown dwarfs, planetary and protoplanetary systems (the dusty disks of planetary debris surrounding some stars), active galactic nuclei and ultra-luminous infrared galaxies, and formation of galaxies in the early universe. Rieke's book can only give a fla vor of t h e m u lt idecade epic. But he, as a major team player, is in an excellent position to reveal the continuing struggle to refine the program. Recently, we have seen the results of this effort in some of the science revealed by the SIRTIF, ultimately named the Spitzer Deep Space Observatory. This was to honor Dr. Lyman Spitzer, who in the 1940s proposed putting telescopes into space, thus above the blurring effects of Earth's atmosphere.
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Briefs: Most Distant Naked-Eye Object Detected
A powerful stellar explosion t h a t 's shattered the record for the most distant naked-eye object visible was detected by NASA's Swift satellite. The gamma-ray burst is also the most intrinsically bright object in the universe ever observed by humans, visible to the naked eye even though its source is half-way across the universe. The afterglow was 2.5 million times more luminous than the most luminous supernova ever recorded. The star, in BoЖtes, is an estimated 7.5 billion light-years away. Three asteroids appear t o b e a m on g ou r sola r system's oldest objects, apparently formed 4.55 billion years ago. Astronomers, observing the asteroids with infrared and visible-light scopes, measured amounts of colors of light reflected from the surface and found evidence the objects contain bits of material rich with calcium and aluminum. An ocean seasoned wit h t h e ch em ica l in gr ed ien t s of life may lie hidden beneath the icy surface of Titan. The size of seasonal wind shifts hints that Titan's crust and core have to be separated by a liquid ocean to allow the atmosphere to move the crust around. Mercury's surface is n ot on ly p ep p er ed wit h im pact craters, but wrinkled with mysterious chains of cliffs. Scientists think the "lobate scarp" cliffs--2 miles high and hundreds of miles long--were created as Mercury's crust bunched around its shrinking interior. But a new theory suggests rising sheets of hot-mantle rock popped out ridges, helping to create the cliffs. For the first time, sa t ellit e im a ger y r evea ls t h ick Martian salt deposits scattered across the southern surface, which could be sites of ancient life. Mats of sodium chloride serve as more evidence of Mars' watery past, and briney pools that made them could have been hospitable to life. The salt deposits are thought to be more than 3.5 billion years old. Scientists have found t h e p r esen ce of a n or ga n ic molecule in the atmosphere of an extrasolar planet for the first time. The signature of the molecule methane is in the atmosphere of Jupiter-sized HD 189733b, 63 lightyears away in Vulpecula. It orbits closer to its star than Mercury, so is unlikely to support life.
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Scientists have detected wa t er va p or in sp in n in g disks that surround two newly formed stars, where planets are born. They spotted water molecules in disks of dust and gas around DR Tau and AS 205A, 457 and 391 light-years away, one of the few times water vapor has been detected in the inner part of a protoplanetary disk. After months of r ela t ive q u iet u d e, a t r io of n ew sunspot groups have appeared and are growing rapidly. Solar Cycle 24 is based on sunspots with reversed polarity. Puzzlingly, the sunspots have magnetic polarity consistent with Solar Cycle 23 rather than the new cycle. Some scientists predict Solar Cycle 24 will be intense. Saturn's rings a r e va n ish in g. T h e wid e-open rings are rapidly narrowing into a thin line, having narrowed considerably in the last year. The Cassini division, a dark gap in the rings, is getting hard to see. As Saturn orbits the Sun, it turns its rings edge-on to Earth once every 1415 years. Because the rings are so thin, they can disappear when viewed through a small telescope. Saturn's rings will thin until, on Sept. 4, 2009, they vanish.

Analyses of March 2007 outbursts of t wo gia n t plumes on Jupiter suggest internal heat played a major role in generating them. The plumes moved faster than any Jovian feature and left global streaks of red-cloud particles. Scientists puzzle over whether internal heat or sunlight, or both, powers Jupiter's disturbances and jets. The plumes erupted at middle northern latitudes, 39,150 miles apart, racing at more than 375 mph. Each mushroomed from its initial diameter to 1,245 miles in a day.
Titan has hundreds of t im es m or e n a t u r a l ga s and other liquid hydrocarbons than all of Earth's known oil and natural-gas reserves. Cassini has mapped 20% of Titan's surface with radar. Hundreds of lakes and seas have been observed, with several dozen estimated to contain more hydrocarbon liquid than Earth's oil and gas reserves. Dark equatorial dunes contain organics several hundred times larger than Earth's coal reserves. Cosmic sprinklers that spurt m ist y j et s fr om cracks along Enceladus could hint at a vast watery lake beneath the moon's icy shell. Data reveal there must be Briefs continued on page 9


Briefs: Saturnian Vortex Has Hurricane-like Features
Continued from page 8 water beneath the surface and support the idea that Enceladus' geysers are the source of Saturn's E-ring. Vapor in the plumes may move at 650-1,100 mph, nearly double the speed needed to escape Enceladus' gravity. The ice grains, however, move much slower. Even with a push from the vapor stream, only 10% of the ice particles have enough energy to break through Enceladus' gravity. But the crystals are recaptured by Saturn's gravity and coalesce to form the E-ring. A test of water vapor spewing from Enceladus shows it's gushing with organic molecules. Cassini recorded the highest temperatures detected near tiger stripe-like fissures on the southern pole, raising the possibility of liquid water beneath the exterior. The fissures are -135 degrees near their centers, 63 degrees warmer than previously observed and 200 degrees warmer than the rest of the surface. Astronomers have peered in t o a st ella r d isk t o capture an image of material falling onto what could be a planet in early formation. The image shows a somewhat horseshoe-shaped void in the disk surrounding a young star, AB Aurigae. Within the void, a barely visible bright spot could indicate a developing object 5-37 times Jupiter's mass. AMNH researcher Ben Oppenheimer said the image shows what's thought to be dust accreting onto the object. He and colleagues blocked out most of the stellar glare by attaching a coronagraph they'd developed to an Air Force telescope on Maui. They also used polarization filters, which show light scattered off the disk. How close can a giant planet get t o a st a r b efor e its atmosphere becomes unstable and it's doomed to catastrophe? A study compared Jupiter to giant exoplanets. Jupiter has a thin, stable atmosphere and orbits the Sun at 5 AUs. Exoplanets, which may orbit 100 times closer to their star, have very expanded atmospheres which boil off into space. A team brought a virtual Jupiter closer to the Sun. At 0.16 AU, it would remain Jupiter-like, with a stable atmosphere. But at 0.14 AU, its atmosphere would suddenly start to expand, become unstable and escape. A massive whirling vortex r ecen t ly d iscover ed over Saturn's south pole has features similar to hurricanes on Earth and unlike anything astronomers have seen. Eyes and eye walls have never been observed anywhere else except on Earth. Saturn's polar vortex is much bigger than any hurricane found on Earth. Its eye alone measures about 2,500 miles in diameter. If Martian life existed a few b illion yea r s a go, scientists think any plant-like microbes would have left behind a stringy fuzz of fibers. That's because on Earth, researchers have found such ancient fuzz, cellulose, in chunks of salt deposited more than 250 million years ago, the oldest biological substance recovered. The samples survived because of their exceptional sturdiness and due to the salty environment. It killed off bacteria, preventing the cellulose from being chewed up as food. Dangerous levels of radiation in sp a ce cou ld b a r astronauts from a mission to Mars and limit prolonged activity on the Moon. Risk uncertainty means safety margins must remain high, limiting how long astronauts can stay in space. NASA's space radiation-biology research has been hit by recent funding cuts, leading to major gaps in knowledge of radiation health risks. Officials may have to trade off a safe amount of protective material with cutting weight to enter space practically. A pair of newfound stars or b it ea ch ot h er so closely that they share material, taking on the appearance of a giant peanut in space. A second freshly examined system has the same two-lobed look. The systems presage a new class of objects. The first system is 13 million light-years away inside a small galaxy called Holmberg IX. Both stars are very bright, yellow stars about 15 times the Sun's mass. In the orbital cycle, one star moves in front of the other, blocking its light from our vantage point, so astronomers see one star, then two, then one, and so on. The other system is much closer, less than 230,000 light-years away in the Small Magellanic Cloud. Images of a tsunami b la st in g it s wa y t h r ou gh t h e Sun's lower atmosphere have been taken for the first time. They have helped astronomers revise estimates of the waves' speeds. Speed is more than 1 million kilometers per hour. Oddly, the tsunami seemed to move just as speedily through dense layers as it did through less dense layers. What causes these giant solar waves isn't clear. They're associated with coronal mass ejections and Continued on page 10
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Briefs: Smallest, Lightest Black Hole Yet Is Identified
Continued from page 9 could be the shock wave that result from them. Astronomers h a ve seen t wo cla sses of u n iq u e ga laxies from the early universe. One was galaxies that looked old even when the universe was young, suggesting they were among the first galaxies to form after the universe's birth. The other group is galaxies dating from the universe's strongest burst of star formation. The galaxies give away their elderly and inactive status by their reddish color, indicative of old stars. The astronomers saw them as they existed 4 billion years after the Big Bang. NASA scientists have identified t h e sm a llest , lightest black hole yet found, 3.8 times the mass of our Sun and only 15 miles in diameter. The black hole sits in a binary system in our galaxy, XTE J1650-500, in the southern hemisphere constellation Ara. Some unknown threshold, possibly between 1.7 and 2.7 solar masses, marks the boundary between a star that generates a black hole upon its death and a star that produces a neutron star. A shower of shooting stars h a s b een r ecor d ed on Mars for the first time. Meteors have been spotted before by Mars rovers, but no device has detected a full shower until now. Just as on Earth, Mars meteor showers can occur when a planet passes through the dusty trail of a comet. Scientists think four times as many comets dust Mars with their tails compared to Earth, as a high proportion of comets are near Jupiter. Astronomers have found a n em b r yon ic st a r younger than any seen before. They saw the 100,000year-old planet 520 light-years away in Taurus. It's 1% percent as old as a young planet found around the star TW Hydrae last year. A new discovery of a m id d leweigh t b la ck h ole suggests black holes come in all sizes. Astronomers have long debated the existence of middleweight black holes, which could be a missing link in the evolution of the universe's first stellar black holes to supermassive black holes that anchor most major galaxies. The sky's largest star cluster, Omega Centauri, might harbor an elusive
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intermediate-mass black hole in its center. Researchers suspect missing mass comes from a black hole weighing 40,000 solar masses at the center of the cluster. Astronomers have tracked down t h e m issin g starting point of one of the two types of solar wind. The parts of the solar wind that emanate from the Sun's equatorial region originate at the edges of bright regions in the Sun's atmosphere and are released when the magnetic fields of two bright regions link up. The fast solar wind originates from coronal hole regions near the Sun's poles. The slow one flows from the equatorial region. Triple black-hole mergers a r e a r ea l p ossib ilit y, according to a supercomputer calculation. Astrophysicists used a computer model to predict what would happen if several black holes were to orbit each other. Often the trio would merge into one giant black hole. Last year, astronomers found the first triple quasar. That could be the first observed supermassive black-hole triplet. Astronomers have discovered p ossib ly t h e sm a llest extrasolar planet yet, a rocky world orbiting a star in Leo. The planet weighs about five Earth masses and is 30 light-years away. Its radius is estimated to be about 50% greater than Earth's radius of 4,000 miles. GJ 436c orbits GJ 436 in 5.2 Earth days, and is thought to complete a revolution about its axis in 4.2 Earth days. Astronomers predicted the small exoplanet due to its gravitational effects on the orbit of an inner planet. Researchers found that for every two orbits of that planet, the new planet completes one. One of the best close-ups of t h e M a r t ia n m oon Phobos reveals fresh details. The Stickney impact crater is Phobos' largest feature with a diameter of almost 6 miles. Crater-wall textures come from landslides that formed as materials fell in the weak gravity. Grooves seem to radiate from the crater, although studies have shown the cracks didn't come from the crater. Some scientists believe the grooves are related to the origin of Stickney, but others speculate they came with space debris from Martian impacts that later pelted Phobos. Clues to the size of a n cien t a st er oid s h a ve com e Continued on page 12


Events on the Horizon May 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 For directions to AAA observing events, check the club's website at www.aaa.org. Saturday, May 10, 8 p. m. Custer Institute, Southhold, N. Y., P George Redlinger of Brookhaven National Laboratory will discuss world's largest microscope, the Large Hadron Collider. Info: custerdonna@yahoo.com. Monday, May 12, 7:30 p. m. Hayden Planetarium Lecture, P, AMNH Sara Segar, associate professor of planetary science and associate professor of physics at MIT, will discuss "Extrasolar Planets and the Search for Habitable Worlds." Wednesday, May 21, 6:30 p. m. AAA annual meeting and board meeting, M, HQ Dinner at 6:30, annual meeting at 7:30. Eddie Oravec and Bob Little will be awarded the Amateur Astronomers Medal. Discussion of events in the last year, financials, goals for next year, voting for board members. Board meeting will follow annual meeting. Friday, May 30, dusk-10 p. m. Observing at Carl Schurz Park, Manhattan. P, T, C Next date: June 27. Friday, May 30-Sunday, June 1 Amateur Observers Society of New York star party Second annual event will be held at Stone Tavern Park in Delaware County, N. Y. Speakers, events for kids and adults, overnight facilities available. Info and registration: www.aosny.org. Saturday, May 31 10 a. m.-noon AAA Solar Observing, P, C Next date: June 28. Saturday, May 31, 1 to 4 p. m. AAA Observers Group, M Next date: June 28.

Friday, May 2, 6:15 p. m. AAA lecture, P David Helfand, professor of astronomy and chair of the astronomy department at Columbia University, will discuss "Global Climate Change: What We Know and What We Don't Know" at the AMNH's Kaufmann Theater.
Tuesday, May 6, dusk-10 p. m. Observing at Cadman Plaza, Brooklyn, P, T, C Next date: June 3. Wednesday, May 7, 8-11 p. m. Observing at Prospect Park, Brooklyn, P, T, C Next date: June 11. Thursday, May 8, 6:30 p. m. Recent Advances Seminar, M New location: Room 405 of NYU's Kimmel Center, 60 Washington Square at corner of La Guardia Place. Tell guard you're attending the seminar and bring ID. Next date: June 12. Friday, May 9, 8 to 10 p. m. Observing at Floyd Bennett Field, Brooklyn. P, T, C At the model airplane flying field. Next date: June 13. Saturday, May 10, 7-11 p. m. Observing at Riverside Park, Manhattan, P, T, C Special observing session in conjunction with the Riverside Park Fund, Check out the Moon in the Beehive Cluster. At 96th Street. Check aaa.org or 718-522-5014. Saturday, May 10, dusk Observing at Great Kills Gateway National Park, Staten Island, P, T, C Next date: June 7.

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AAA Annual Meeting May 21
In accordance with the AAA bylaws, t h e 2008 a n n u a l m eet in g will b e h eld on W ed n esd a y, M a y 21 a t AAA headquarters, 1010 Park Avenue, between 84th and 85th streets. 6:30 p. m.: buffet dinner. 7:30 p. m.: annual meeting, for all AAA members. The 7:30 p. m. meeting will include elections to fill vacancies on the AAA board of directors. Nominations, besides those made by the nominating committee, may be presented to the AAA president or to the recording secretary no later than seven days before the annual meeting. Each such additional nomination requires the signatures of at least 18 AAA members.

Continued from page 10 from the chemistry of ancient seawater. Impactors may leave behind chemical traces in ancient ocean-floor sediments that can signal their impact and record what was floating around in the seawater in the distant geologic past. A new study has found higher levels of an isotope of the element osmium in ocean sediment layers that correspond to the timing of known impacts. They can also utilize the isotope levels to estimate the size of impactors. Astronomers have found t h e cold est b r own d wa r f to date. The failed star might represent a new class of objects that are a missing link between planets and stars. The cold brown dwarf floats freely in space, not bound

to a star. Its mass is 15-30 times Jupiter's. It's about 660 degrees, cooler than any known object in its class. The brown dwarf is about 40 light-years away. The mass of brown dwarfs is usually less than 70 Jupiter masses. The brown dwarf looks much more like a giant planet than known classes of brown dwarfs because of its low temperature and the presence of ammonia.

Contacting the AAA
If you want to join, volu n t eer , p a r t icip a t e in events, have a question or change your address, e-mail members @aaa.org, or leave a message at AAA hq: (212) 535-2922. Also, visit us on the web at www.aaa.org. If you're interested in writing an article for Ey epiece, contact editor Dan Harrison at edi-

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