Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.aaa.org/EyepieceFiles/aaa/2007_07_July_Eyepiece.pdf Дата изменения: Sun Feb 22 20:31:05 2015 Дата индексирования: Sun Apr 10 03:36:44 2016 Кодировка: Поисковые слова: antarctica

Journal of the Amateur Astronomers Association of New York July 2007 Volume 55 Number 7, ISSN 0146-7662

EYEPIECE

AAS Meeting Illustrates Changing Nature of Astronomy
By Rachel Berger Connolly
Standing in the Honolulu Convention Center for my first American Astronomical Society meeting in May, I realized that time and technology does a lot to a field of research so dependent on imaging and automation.
I attended to present a poster session on the Field Trip to the Moon project on behalf of the AMNH. Secretly, I was looking forward to the meeting. For years, I had followed press releases from AAS meetings. It wasn't what I expected.

ble a new way of doing astronomy, moving from an era of observations of small, carefully selected samples of objects in one or a few wavelength bands, to the use of multi-wavelength data for millions, if not billions of objects. Such datasets will allow researchers to discover subtle but significant patterns in statistically rich and unbiased databases, and to understand complex astrophysical systems through the comparison of data to numerical simulations. The NVO will provide simultaneous access to multi-wavelength archives and advanced visualization and statistical analysis tools." With a virtual observatory, anyone can go to the Internet, call up objects needed for their research, and never have to spend a night worrying about the weather and midnight lunches. Due to these sky surveys and automated telescopes, questions previously asked about individual stars and galaxies can now be answered about entire statistical groups of objects, hundreds at a time, that have been isolated from a survey.
Research can increasingly be done with use of archival data from sky surveys. What does that mean for the amateur astronomer and the public astronomy educator (often the same person)? Today's graduate students in astrophysics might never need to operate a telescope or go on an observing run to do their research. They can simply download images, spectra and other needed data. But as objects of research grow more distant, and questions more complex, the communications gap between the public and the professional astronomer may grow. As an informal education community that holds a leadership role in astronomy, amateurs face a changing landscape of research that compels them to work on new strategies for communicating and navigating this growing universe, thus bridging the digital divide.

I learned more about the releases from CNN.com than from the meeting. For example, a new Hubble image of M81 was splashed across various media channels. At the conference, I walked past a poster of it a few times before I realized it wasn't just another ad poster.
There were three rows of booths, mainly staffed by NASA and the NSF, which advertised facilities, telescopes, missions and research-grant opportunities. Despite booths full of information, these meetings are increasingly virtual in nature. The schedule and abstracts of every session are available online. You can follow content strands throughout the meeting. It struck me in Honolulu how much astrophysics is changing due to sky surveys and large data releases. When I was an undergraduate in astronomy in the early 1990s, many papers were about specific stars or galaxies. A few objects produced observing runs for several nights. In development is the National Virtual Observatory, where much of the sky has been seen by robotic telescopes and a digital-image library has been created.. As noted on the NVO website, "The NVO will ena-


What's Up
By Tony Hoffman The Sky for July 2007
The Lion's Share of the Action. I f you look t o t h e west in the early evening as July opens, the familiar form of Leo the Lion is punctuated by a pair of bright planets standing less than a degree apart. On July 1, only 47 arcminutes separates Venus from Saturn. Both worlds are heading towards conjunction with the Sun. Though Saturn is on the opposite side of the Sun from Earth, Venus will be passing more or less between Earth and Sun. As Venus approaches this so-called inferior conjunction, its disk will grow larger, but appear as an ever-thinner crescent. At mid-month, our sister world reaches its peak brightness at magnitude -4.7. This is a great opportunity to see a planet in broad daylight with the naked eye or through a telescope, though be careful never to point a scope without proper solar filter anywhere near the Sun. July's Constellations. O n J u ly even in gs, t h e su m mer Milky Way stretches across the sky, extending from Cassiopeia up through Cepheus to Cygnus in the northeast, then down through Aquila, Scutum and Ophiuchus to Scorpius and Sagittarius in the south, marking the galactic center. Vega stands high in the east, Arcturus begins to dip west, and Hercules and Corona Borealis lie near the meridian. Virgo lies to the southwest. Jupiter blazes in southern Ophiuchus above Antares. Asteroid 4 Vesta, at magnitude 6.1 a good target for city binoculars , swings through Scorpius a bit west of Jupiter. The Big Dipper sinks into the northwest. By late in the month, the Great Square of Pegasus swings into view in the northeast before midnight. Mars, which travels through southern Aries into Taurus, ends July just 7 degrees from the Pleiades, by which time it will have brightened to magnitude 0.5. Mars is best for early risers in July; it doesn't rise until well after midnight.

As July opens, Venus and Saturn stand less than a degree apart in the constellation Leo. July 1 Venus lies 0.8 degrees from Saturn (see above). July 6 Earth is at aphelion (94.4 million miles from the Sun). July 7 Last-quarter Moon at 12:54 p.m. July 9 Moon lies near Mars; Moon at perigee (228,992 miles from Earth), 5:42 p.m. July 12 Venus is at greatest brilliancy, magnitude -4.7 (see above); Moon lies nea r Mer cur y. July 14 New Moon at 8:04 a.m. July 16 Venus lies near Regulus; Moon nearly occults Saturn. July 17 Moon lies near Regulus and Venus. July 20 Mercury at greatest elongation in morning sky. July 22 First-quarter Moon at 2:29 a.m. July 25 Moon lies near Antares and Jupiter. July 28 Southern Delta Aquarid meteor shower peaks. July 29 Full Moon at 8:48 p.m.

Mercury Shone in the West While Venus Passed Dichotomy
By Joseph A. Fedrick
Mercury briefly emerged form the solar glare for a good apparition in late May and was visible with binoculars far below Venus on May 29. Mercury appeared like a pale off-white or very-pale tan star while Venus was
2

much brighter and whiter. Saturn was a tiny pale oval spot of light, the rings not quite resolved at 10x. Jupiter appeared as a tiny ivory white oblate disk, larger than Saturn and accompanied by tiny 4th magnitude points of light: the Gallilean, Jovian moons. Fedrick continued on page 11


A Message from AAA President Richard Rosenberg
Hello, members: It's summertime, and while our lecture series is in hiatus, chair David Kraft has been active at lining up speakers for the 2007-08 season. We'll begin with a bang as Mario Livio, director of the Space Telescope Science Institute, which runs the Hubble Space Telescope, will speak on October 5. Stay tuned for announcements of the other lecturers. Summer is also a great time to be outdoors, and what outdoor activity is better than observing the night sky? In addition to our regular observing sessions in the city and at the Anthony Wayne Recreational Area, we 'll organize a few trips to darksky locations. If you're interested, contact me at outoftown@aaa.org or give me a call. As noted in Ey epiece last month, Susan Andreoli has stepped down as financial secretary (because of the demands of her job). Until I became president, I didn't know exactly what the financial secretary did, but I soon found out. Susan and Tom Haeberle, our treasurer, kept our financial records in order and believe me, it 's a lot of work. Thank you, Susan, for all you've done. Susan has also left the board. We are fortunate to have found a replacement, Jeremy Browner. Jeremy is an attorney familiar with nonprofit law whose knowledge and energy will be a great asset to the club. He 's already come up with several ideas for improving the club. Rich Rosenberg, AAA President, pr esident @a a a .or g, (718) 522-5014

Two Impressions of (Delayed) Sidewalk Astronomy Night
By Bruce Kamiat
Saturday, May 19 had been declared International Sidewalk Astronomy Night; and it was observed by observers all over the world. Here in New York City, it was clouded out. Many of us decided on Sunday night as an alternative. It was a shame we had to miss the spectacular close conjunction of Venus with the crescent Moon, the main reason for having chosen the 19th. Sunday afternoon, the weather still wasn't looking good, with clouds and thundershowers predicted for evening. I watched my computer and pondered satellite images, National Weather Service forecasts and the Clear Sky Clock. By 7, the Weather Service forecasts were still grim, but the Clear Sky Clock predicted the weather would clear about 8, and satellite images showed the clouds moving off to the east and clear skies coming from the northwest. I decided I'd go for it. The Clear Sky Clock was exactly correct, and it cleared up beautifully just minutes after I arrived at the observing site. It remained wonderfully clear all evening. Kamiat continued on page 6

By Richard Rosenberg
One of the most important and enjoyable things we can do as telescope and binocular observers is to introduce members of the public to the wonders of the night sky. Saturday evening, May 19, was International Sidewalk Astronomy Night, when amateur astronomers from all over the world were asked to show people the universe. Unfortunately in New York City we were rained out, but the following evening was clear so I decided to take my scope to the Brooklyn Heights Promenade. I was joined by a photographer from amNewYork for an article on the club and amateur astronomy in New York City. On May 19, the Moon and Venus were only a degree apart and would have provided a spectacular naked-eye view. Though the Moon had moved on, these two and Saturn provided plenty of entertainment. As you might expect, the Moon and Saturn made the biggest splash. Under high power, lunar craters were spectacular and evoked screams of incredulity. Saturn Rosenberg continued on page 10 3


JPL Aide Outlines Parameters in the Search for Life
By Katherine Avakian
"Exploration is a biological imperative. All organisms explore. Science makes exploration significant," said Pamela Gales Conrad of NASA's Jet Propulsion Laboratory in a May 14 Hayden lecture on "Habitability Potential and Life Detection on Other Planets." Conrad made the scientific processes used in this search more understandable by spelling out their component parts. She also described the mobile science lab being readied for a 2009 launch to Mars. Its sophisticated array of instruments will "assess a local region of Mars' surface as a potential habitat for life, past or present.." The search for life isn't aimed at intelligent life, Conrad noted. She emphasized that most life on Earth is microbial "in sheer numbers and amount of biomass. Microbes have very, very robust strategies for dealing with the breadth and depth of environmental challenges-the deepest deep, the hottest hot, the coldest cold, the highest altitudes, places that are entirely besieged by radiation." Therefore, she said, one should look for anything that might be alive now or was in the past, and for the properties that are involved in producing an environment that's supportive of life. In surveying planets for habitable zones, spectroscopy could be used to detect water. Analysis of a planet's atmosphere might show gases coming from an ocean as it interacts with the atmosphere. Other things to look for would be such energy sources as sunlight, geothermal energy and radiation from space. One would also try to determine if raw materials are present on the surface and if there's the presence of a biological function through the spectral signatures of pigments or signs of vegetation. Conrad theorized a planet "absolutely would look different if it has a biosphere than if it has not." Conrad described measurable parameters for life detection. They include the terms alive, dead, preserved (dead and preserved in some way, such as a fossil), or non-life (never was alive). She said life should be described in the most universal sense and in measurable terms. Thus, one could talk about its structure or shape, unique chemistry, energy uptake and conversion, and
4

whether it has meaningful movement. One can also gauge if the organism can replicate and evolve. She described NASA's approach to planetary exploration, a system that can also be applied to Earth exploration. The first step would involve remote sensing, scanning large areas of a planet's surface by ground-based telescopes, taking pictures, using spectroscopy and gauging temperature by measuring thermal emissions. The next step would be confirmatory from surface contact.

The third stage would consist of much time on finescale studies of small regions of the planet, using a variety of tools and instruments, and analyzing findings. Some instruments are first experimented with in Earth exploration and then sent to Mars. The last two stages, returning samples to Earth and human exploration, are as yet unrealized in planetary exploration.
Projected for launch in late 2009, NASA's Mars Science Laboratory, a giant instrument-laden rover, is planned to operate for at least a Martian year (687 Earth days). Conrad observed its scientific objective is "to assess the biological potential...see what we can learn about the geology and geochemistry...try to understand the radiation environment in preparation ultimately for human exploration." Conrad, who's helping to develop the project's payload, noted permission has been granted to equip the rover with a nuclear-powered radiothermal generator, which will last a long time and permit operation of several experiments simultaneously. It will have a slow-motion video camera, gas chronometers and a mineralogy package. Its instruments will tell whether there's water nearby and discern information about a rock's chemical elements from a distance of nine meters. On the possibility of the rover contaminating Mars with microbes from Earth, Conrad said, "There are constraints as to where they can land. They're not using the airbag approach. They're using conventional rockets. Also, they're forbidden to go anywhere on Mars where [there's] water within the top meter of the surface, so should there be microbial life taking advantage of that water, we would avoid that."


Review: A Sun Follower's Triumph and Tragedy
By Thomas Haeberle
Every so often a book brings the past and its people to life. Stuart Clark's "The Sun Kings: The Unexpected Tragedy of Richard Carrington and the Tale of How Modern Astronomy Began" (Princeton University $27.95) is such a story, comparable to Dava Sobel's "Longitude" and Tom Standage's "The Neptune File." The science of the Sun, though times taken for granted. Even though impacts our lives, the origin of this discussed. Clark takes us back to when solar discoveries helped herald absorbing, is somethe Sun profoundly discipline is rarely the Victorian age, modern astronomy. his beloved house in Redhill. At 39, he moved to Churt with dreams of building another observatory. In 1868 while visiting London, he met a beautiful young woman, Rosa Helen Rodway. Though she wasn't well-educated and a complete stranger, he courted her and they married the following summer. This encounter would have tragic consequences, especially for his young bride, who was already married. Shortly after the end of this twisted triangle, Carrington also ended his life.

The book begins on September 2, 1859, when "the entire Earth was engulfed in a gigantic cloud of seething gas, and a blood-red aurora erupted across the planet from the poles to the tropics. Around the world, telegraph systems crashed, machines burst into flames, and electric shocks rendered operators unconscious." The day before, astronomer Carrington had witnessed an event never seen before on the Sun, an extraordinary flare seen in "white light!" He'd be the first to determine that the Earth isn't immune to interstellar influences. The name Carrington would often be mentioned as a footnote in books or a text, but there's a story to tell about the man behind the name. He was the first to recognize that the Sun didn't rotate as a solid ball as originally thought by William Hershel and others. By observing sunspots at different latitudes, he saw those nearer the equator were being swept around the Sun three days faster than those at higher latitudes. This differential rotation is something only a gaseous ball does. Carrington, crowned by his peers as the Sun King, did work that led to today's solar science. He achieved much despite suffering personal tragedies and being suspect in a crime of passion. Carrington was awarded the Royal Astronomy Society's Gold Medal, "ostensibly for his epic catalog of 3,735 stars compiled in three years." Carrington never achieved the jobs he desired. Despite being burdened with the family brewery business, he struggled to carry on with solar observations. Eventually he sold the business, astronomical equipment and

Though the book's main character, Carrington followed the lead of others, and in turn passed the torch to other scientists. Clark brings such prominent people to life as William and John Hershel, Heinrich Schwabe, E. W. Maunder, George Airy and George E. Hale.
Particularly engaging is the chapter on William Herschel as one of the earliest pioneers of solar discovery. Gradually his theories went from an inhabited solid Sun to a more practical look at how it affects climate. Other pioneers in solar science in the book are Warren de la Rue for photography and Annie Russell (eventually Mrs. Maunder) for tracking sunspots and helping to correlate them to climate changes. Joseph Fraunhofer and Robert Bunsen pioneered the way for spectral analysis of light, enabling scientists to view spectroscopic flares in different wavelengths. The biggest factor in the modern age was Hale for his observations of the Sun and as inventor of the spectroheliograph. Clark writes for the European Space Agency a regular contributor to such magazines as "New tist" and "BBC Focus." He's authored several including "Journey to the Stars" and "Universe in The Story of the Hubble Telescope." and is Scienbooks, Focus:

New Astronomy-Related Play
An astronomy-related play is coming to Manhattan Theater Center's City Center home next season. "The Starry Messenger," by Kenneth Lonergan, stars Matthew Broderick as a man who teaches astronomy at a college and at the Hayden evenings. When this 40-something married man meets a pretty young single mother, his own solar system begins spinning out of control.
5


NY Light-Pollution Bill Fails to Emerge from State Senate
The Healthy, Safe and Energy Efficient Lighting Act, designed to curb excessive and misdirected outdoor lighting in the state of New York, failed in the legislative session which ended June 21. The State Assembly passed the most 3-1 margin, 93-33, June 20. T mental Conservation Committee had 30, but the bill went from there to the mittee, from which it never emerged. measure by an alhe Senate Environvoted in favor May Senate Rules ComSenate Republican majority leader Joseph Bruno and Gov. Eliot L. Spitzer, Rosenberg said: "As amateur astronomers we see the effect of wasted lighting first hand, as it washes out our view of the heavens. This is true not only in New York City but is becoming more apparent in suburban and even rural areas of our state. "This issue affects all of us, not only astronomers. Poorly designed light fixtures waste energy on a massive scale. Given current geopolitical and environmental considerations, we should do all we can to reduce our energy requirements and in particular our reliance on oil. Fixtures which direct light downward do not waste light, and can deliver the same lighting capability with less wattage. "We realize how important good lighting at night is to pedestrians and drivers. We are not asking for anything that would compromise the safety of the public. Directing light downward where it is needed, and not upward where it only pollutes the night sky, will yield a significant reduction in our energy requirements and costs."--Dan Harrison

The key provision of the legislation prohibited public entities to install new or replacement permanent outdoor luminaires unless a fixture with lamp or lamps greater than 1,800 lumens was fully shielded. Exemptions included lighting that's part of a continuous roadway design, or historic-style luminaires.
Earlier, AAA president Richard Rosenberg, speaking on behalf of the board and club members, urged legislators to support the measure. In a May 27 letter to Assembly sponsor and Manhattan Democrat Linda Rosenthal, Senate sponsor and Nassau Republican Carl Marcellino, Kamiat continued from page 3 The lesson: Trust the Clear Sky Clock, especially when satellite photos back it up. All the participants had posted their plans on the Net. That way we could coordinate wide coverage. The concept was to disperse as much as we could and go where we normally didn't, to relatively high-traffic areas where the public was. I headed to Central Park West at 81 Street. A fair amount of sky is visible there. Signs told passersby what we were doing, invited them for a look and reassured them we weren't charging. Venus was our first target: gorgeous in the scope and clearly showing its slightly gibbous phase through a glare-reducing 80A blue filter. Many people expressed their awe at the sight. Despite its dazzling brilliance, few people realize you can see Venus with the naked eye. It doesn't occur to them that the bright light they see in the sky is a planet. First-time telescopic viewers are always impressed by the planet's phases, too.
6

The Moon is also awesome to those who've never seen its craters, peaks, and plains except in photographs. The easily visible earthshine was an eye-opener to many viewers. Later, we turned to Saturn and globular star clusters M3 and M13. Under the street lights, bright planets were far more popular than faint, fuzzy clusters. Several people from the neighborhood ran upstairs to bring family members down for a look. A number of the viewers who came to us had heard about the event from the New York Sidewalk Astronomers Yahoo group or from various other Internet sources. Viewers were diverse. A visitor from Stuttgart was astonished that one could see anything in the New York City sky. He was excited by his first-ever views of Venus and Saturn, but even more by the fact that we were out in the street bringing these views to the public. An amateur astronomer from Seattle also expressed her excitement at this. She had experience with backyard astronomy, but had never encountered sidewalk astronomy before.


Online Amateur Astronomers Seek Out New Worlds
The following article, by The Associated Press' Alicia Chang, has been edited for space. Amateur astronomer William Bianco doesn't huddle over a backyard telescope to hunt for undiscovered planets. He logs onto his computer. Bianco, a political science professor at Indiana University, is part of a growing online community that sifts through mountains of data collected by professional scientists in search of other worlds. While he's yet to make a landmark discovery, he savors the rush of teetering on the cutting edge of research. Never before have amateur astronomers had so much unfettered access to celestial data once available only to scientists with huge telescopes. In the latest frontier of astronomy, professionals are increasingly enlisting the aid of novices with personal computers to help pore through images and data. Thanks to technology, novices are effectively turning from lonely skywatchers to research assistants. Even before the rise of virtual astronomy, amateurs did everything from tracking asteroids to detecting supernova explosions to eyeing new comets. In 1995, neophyte stargazer Thomas Bopp gained fame for co-discovering what would be known as Comet HaleBopp. Two years ago, in what was billed as the first such find by an amateur in 65 years, Jay McNeil of Kentucky took a picture of a new nebula, an illuminated cloud of gas and dust lit by what is believed to be a newborn star. Since the late 1990s, virtual astronomy has boomed. One of the earliest online citizen-scientist projects was SETI(at)home, which distributed software that created a virtual supercomputer by harnessing idle, Webconnected PCs to search for alien radio transmissions. Newer efforts require more human thought. Bianco belongs to an Internet project called Systemic, which boasts 750 amateur planet hunters. Astronomers have discovered more than 200 planets using traditional methods. Participants download software and rifle through data that measure the tiny gravitational wobble in a star's motions in search of planets. Users also try to decode simulated data of planetary systems invented by project managers, a task that will help professionals better understand real planets. To participate, users select a star--real or simulated-and adjust other variables such a planet's mass and orbital period by moving a slider back and forth on the screen. The goal is to design a planetary system that best fits the data and publish the answer online.

So far, online users have pinpointed hundreds of potential candidates, but only about five might actually be real, says Systemic project head Greg Laughlin, an astronomer at the University of California/Santa Cruz.
Although the Systemic website provides search tools, it doesn't promote any discoveries. Amateurs who want to publicize their find need to look for another outlet. Laughlin helped start a project in which amateurs point their telescopes at potential extrasolar planetary systems and look at dimming starlight to learn about a planet's size and composition. Unlike Systemic, users have to buy expensive equipment. Before Internet-based astronomy, it took a long time for novices to report their discoveries. High-speed, always-on Internet access has blurred the line between the professionals and amateurs, says Terry Mann, president of the Astronomical League, made up of more than 240 U.S. amateur-astronomy clubs. Last year, Mann signed up to analyze a repository of online images of the first-ever microscopic grains of stardust brought back to Earth by a NASA spacecraft. The work is painstaking. Mann and her fellow 25,000 volunteers eye hundreds of thousands of digital images in search of minuscule carrot-shaped trails left by the stardust, believed to be the leftovers from stellar explosions. She's submitted 40 possible examples of stardust in the images. If correct, amateurs can get their names published in scientific papers. Online continued on page 10
7


Briefs: Promising Exoplanet May Not Support Life After All
Scientists earlier this year announced they had found a small, rocky planet just far enough from its star to sustain liquid water on its surface, and thus possibly support life. It turns out they might have picked the right star for hosting a habitable world but the wrong planet. Gliese 581c is probably too hot to support liquid water or life, computer models suggest, but conditions on its neighbor, Gliese 581d, might be just right. Gliese 581c was the first exoplanet found that resides within the habitable zone of its star, if only barely. The habitable zone is the region around a star where the temperature is neither too hot nor too cold, so water can exist on a planet's surface in its liquid state. But new simulations of the Gliese 581c's climate suggest the planet is no earthly paradise, but rather a faraway Venus, where carbon dioxide and methane create a runaway greenhouse effect. Spitzer has detected about 1,200 previously unknown dwarf galaxies in the Coma Cluster 320 million light-years away. Astronomers pieced together 288 Spitzer exposures. Each lasted 70-90 seconds, forming a mosaic covering 1.3 square degrees of sky when combined with Sloan Digital Sky Survey data. Almost 30,000 new objects were found relatively quickly. Many were Coma galaxies. Additional Coma dwarf galaxies might lurk in the Spitzer data. The dwarf planet that effectively forced astronomers to strip Pluto of its planethood isn't only bigger than Pluto but much more massive. Eris, discovered in 2005, is 27% more massive than Pluto. The finding confirms Eris and Pluto have similar compositions. Eris circles the Sun from about 9 billion miles away, twice the distance of Pluto at its farthest point. To determine Eris' mass, researchers used Hubble and Keck to calculate the orbital speed of its moon, Dysnomia. The more massive a celestial object is, the faster its satellite will zip around it. Eris' diameter is believed 1,490-1,860 miles vs. Pluto's 1,430. Knowing Eris' mass and size, researchers could confirm that Eris' density is similar to Pluto's, and is therefore likely made up mainly of rock and water ice. Astronomers have measured once-theoretical speeds of gamma-ray bursts for the first time. The observation came thanks to quick, automated observations of major galactic catastrophes. On April 18 and June 7 last year, Swift detected bright gamma-ray bursts and notified the
8

small REM telescope. Just 40 seconds after each explosion, the robotic observer aimed its lens at the event. Although the initial explosions were invisible at first, the intense energy heated up nearby gas which could be seen in near-infrared by the telescope. By studying the changing brightness of both bursts, scientists measured how fast matter was careening from them. Scientists have pinpointed the locations of a pair of supermassive black holes at the centers of two colliding galaxies 300 million light-years away. Infrared images reveal each black hole at the center of the merger called NGC 6240 is surrounded by a rotating disk of stars and cloudy stellar nurseries. Hubble images showed the outer parts of the colliding galaxies in visible light, revealing long tidal tails made of orphaned stars, gas, and dust. Subsequent Chandra observations revealed two supermassive black holes at the center of each galaxy, and the Very Long Baseline Array spotted two radio sources in the galaxies' central regions. Scientists estimate the black holes will merge in 10 million-100 million years. New research into the chemical composition of stars could identify our Sun's long-lost family and begin to unravel the complex history of our galaxy. Three open star clusters in the Milky Way were examined; our Sun was born in an open cluster. Data have confirmed stars in each open cluster share the same chemical composition. Such homogeneity is expected if all stars form together within the same gas cloud. This resemblance between the clusters' stars indicates the original gas cloud was well mixed before star formation. A "failed star" with only 24 times the mass of Jupiter is the smallest known object to spout jets of matter from its poles. The finding confirms that a range of celestial objects can generate such outflows. It raises the possibility that large gas-giant planets like Jupiter and Saturn might have been gushers earlier. The new object is a previously identified brown dwarf. Called 2M1207a, it's ringed by gas and dust, similar to the protoplanetary disks from which planets form around young stars. It also harbors a 5-Jupiter-mass planetary companion. The gas giant, 2M1207b, was one of the first exoplanets to have its picture taken directly. 2M1207a's jets extend 620 million miles into space, speeding away at a few kilometers per second. If a jet-spewing gas giant were Continued on page 9


Briefs: New Way Found to Forecast Solar-Radiation Storms
Continued from page 8

ever spotted, it would show another similarity between star and planet formation. A scientist using the Solar and Heliospheric Observatory has found a new way to forecast solar-radiation storms, offering up to one-hour warning. The particle most feared by astronaut-safety experts is the ion. The key to predicting when ions will arrive is electrons, always detected ahead of ions. The scientist found that by measuring the time and intensity of the initial electron surge, he could tell how many ions were following and when they would arrive. This reduces odds of exposure by more than 20% compared to current methods. Chandra's X-ray vision revealed a cloud of energy bursting from the center of galactic cluster 3C438 equivalent to 1 billion exploding Suns, possibly the universe's most energetic event ever detected. Either two dense galaxies are colliding at 4 million mph, or a supermassive black hole is swallowing the mass of 100 stars each year. The energies in the cluster are more than 13 times hotter than the Sun's core. The burst is equivalent to the explosion of an entire galaxy worth of stars at once. Radiotelescope images of the cluster reveal two mushroomcloud-like jets spouting from either side of a glowing hotspot, representing a radio galaxy. Goddard astronomers have developed an alternative black-hole weighing technique. Instead of using gravity, astronomers examine the spinning accretion disk of hot gases that black holes gobble from neighboring stars. The method may have enabled detection of two theoretical, intermediate-mass black holes, 1,000 to 2,000 solar masses. But astrophysicists aren't certain how they can form. Astronomers think stars in dense clusters feed small black holes with hot gas, creating larger sizes. Or merging of several black holes could form a bigger one. Streams of hot gas swirling around Saturn have been traced to two icy moons previously thought to be geologically dead. The finding suggests Tethys and Dione might be volcanically active. After being ejected from the moons, gas with charged particles becomes trapped inside the magnetic field surrounding Saturn. They remain trapped only temporarily because Saturn spins so

fast about its axis that it drags its magnetosphere and the trapped plasma inside it rapidly through space. Saturn's rapid rotation flattens the plasma into a disc, with giant fingers of gas thrown into space from the disc's outer edge. Ejected plasma particles get swept away by the solar wind. The particles were traced back to the orbits of Tethys and Dione. Saturn's largest ring might appear solid when viewed from Earth, but closer inspection by Cassini revealed it's composed of tightly packed clumps of particles constantly colliding with one another. Research also suggests Saturn's rings might be two or more times as massive as thought. To measure the B ring's particle distribution, Cassini observed brightness of a background star as rings passed in front of it. Ring particles come together to form giant clumps called self-gravity wakes that can reach 100-160 feet across. Because they're so close to Saturn, their different speeds counteract the gravitational attraction they feel for each other and stretch them out. At any given time most particles will be in one of the clumps. Particles keep moving from clump to clump as clumps are destroyed and new ones form. Titan is still yielding new details years after scientists first pierced its haze. Huygens images reveal extremely rugged terrain in the bright highlands north of the probe's landing site. This includes channels divided by ridges that can rise 500 to 650 feet, with slopes of 30 degrees. Their shapes suggest drainage channels, cut by liquid methane falling as rain. Any surface lakes and seas might be confined to Titan's polar regions. First tests in a project aimed at solving mysteries of the universe and the Big Bang have been delayed from November to April or May next year due to minor equipment problems. The project at CERN involves smashing particles together at high speed in a channel around an oval-shaped 17-mile underground tunnel. This will recreate conditions which existed nanoseconds after the Big Bang and allow scientists to see what happened next. They'll also seek knowledge about dark matter.

The strongest evidence that Mars was much wetter than now has been unearthed by the Spirit rover. A patch
Continued on page 10 9


Briefs: New Evidence that Mars Was Much Wetter than Now
Continued from page 9

of soil seems rich in silica, which suggests it would have required water to produce. Spirit previously found other indicators of long-ago water, such as patches of waterbearing, sulfur-rich soil, alteration of minerals and evidence of explosive volcanism. One possible origin for the silica: interaction of soil with acid vapors produced by volcanic activity in the presence of water; the material could also have formed in a hot-spring environment.

deep hole or cavern, Mars Reconnaissance Orbiter images imply. The 330-foot opening is on a bright dusty lava plain. The hole might be the sort of place that could support life. Because the spot lacks a raised rim or ejecta, researchers have said it isn't an impact crater. The pit must be very deep to prevent detection of the floor from natural daylight.

Rosenberg continued from page 3

Once-flat Martian shorelines were disfigured by a massive toppling over of the planet. This warping of Martian rock hid evidence of oceans, which have been gone for at least 2 billion years. Before toppling over 50 degrees to the north, Mars probably lost some water. The volume was too large to evaporate into space, so scientists think there are still subterranean reservoirs. They think shorelines were once near the equator, but warped into hilly rock elevations as they moved north. By calculating the deformation, researchers found the ridges had to have once been flat. Scientists suspect forces beneath the surface caused the toppling of the planet.
A NASA-sponsored National Research Council report urges robotic return of samples from Mars as a top priority. The report said the "follow the water" tactic should be expanded to "follow the carbon" and other relevant elements. The study said NASA should use Earth-centric and non-Earth-centric approaches that focus on basic concepts in carbon chemistry, imaging, mineral assemblages and isotopic measurements. New data suggest Mars' core of molten iron, nickel and sulfur will solidify--either from the outside in, forming an iron-nickel core, or from the inside out, forming a core of crystallized minerals. A cooling core might restore Mars' magnetism. If liquid metal moves around a solid core, it could create a natural dynamo. The way the interior will freeze depends on how much sulfur is mixed with iron and nickel; the core is 10%-16% sulfur. A low amount of sulfur would cause nickel and iron to solidify in chunks near the outer edge of the core, which would sink to the center. A heftier portion of sulfur would cause a mineral to form in the center and grow outward.
10

was also a big hit with its rings and satellites. Though Venus took third place, its half-lit appearance and incredible surface brightness amazed.
While someone looked through the scope, others asked questions about all areas of astronomy: Is Pluto a planet? How hot are stars? What is the fate of the universe? A major part of our mission the public. We can make allies pollution and increase support f Plus it's a lot of fun. Why not show people some sky? is to bring astronomy to in our fight against light or astronomical research. take your scope out and

Online continued from page 7 Andrew Westphal, associate director of the Space Sciences Laboratory at Berkeley, praised amateurs. It would probably take his whole life to find all the dust sprinklings, he said. "It's stunning how good they are. I think they're better at this than we are." The Internet has also benefited professional astronomers, who often have to fight for scarce telescope time at major research observatories. Since 2001, the National Science Foundation has funded a $10 million project to create a "national virtual observatory" that compiles data from ground and space-based telescopes, including images from the Hubble and X-ray data from Chandra. The project, still under development, is primarily used by professionals who want to go to one source to mine archival images. High school and college students are increasingly tapping into the website as well.

A very dark spot on Mars could be an entrance to a


Events on the Horizon July 2007
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 Check the AMNH's website at www.amnh.org for an additional listing of other events. Tuesday, July 3, dusk to 10 p. m. Observing at Cadman Plaza, Brooklyn, P, T, C Next date; August 7 Saturdays, July 7, 14 and 21, dusk to 3 a. m. Observing at Anthony Wayne Recreational Area near Bear Mountain, P, T, C For directions, see aaa.org. Next dates: August 11 and 18 Thursday, July 12, 6:30 to 8:30 p. m. Recent Advances in Astronomy Seminar, M, HQ Next date: August 9 Saturday, July 14, dusk Upper Manhattan Observing, P, T, C Inwood Park, 218th Street and Indian Road. Next date: August 11 Saturday, July 14, dusk Stargazing, Great Kills Gateway National Park, Staten Island, P, T, C At the model airplane flying field. Next date: August 11 Wednesday, July 18, dusk to 10 p. m. Prospect Park Observing, P, T, C For directions, see aaa.org. Friday, July 27, 7 p. m. Stargazing, Carl Schurz Park, Manhattan, P, T, C

Next date: August 24

Saturday, July 28. 10 to noon Central Park Solar Observing, P, C Conservatory Waters. Next date: August 25
Saturday, July 28, 1 to 4 p. m. Observers Group, M, HQ Julian Parks will speak on "Choosing and Using Binoculars." Next date: August 25

Fedrick continued from page 2

During May and June, I noticed that on many nights Jupiter's south equatorial belt looked tangibly fainter than the north equatorial belt. I detected the fading of the belt at 50x in my 60-mm. refractor. Using the 6-inch reflector revealed the fading as very subtle and uneven. The belt looked faded on May 30 and June 5, but didn't appear faded May 31 when viewed at 150x. The Great Red Spot appeared barely visible as a faint tan smudge near the preceding limb of Jupiter May 30.
Saturn appeared as a pale yellowish disk with a whitish bright A ring and a barely visible Cassini division and a grayish outer B ring at 150x. The planet's shadow was cast onto the rings, giving the view of Saturn a strange three-dimensional effect. The poles of Saturn appeared above and below the rings as the angle of the rings was more shallow than in most recent years. Venus passed dichotomy (half phase) in early June and appeared distinctly crescent-shaped at 50x in my 60mm. refractor. Venus and Saturn appeared closer together in the sky during early June as if in anticipation of a spectacular close approach in late June and early July.
11

Contacting the AAA
If you want to join, volunteer your time, participate in events, have a question or need to change your address, e-mail secretary @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 editor@aaa.org or (914) 762-0358.


Kenneth Franklin, Former Top Official at Hayden, Dies at 84
Kenneth L. Franklin, former chair of the Hayden Planetarium, died June 18 at 84. Franklin was on the Hayden staff from 1956 to 1985. While a research fellow in radio astronomy at the Carnegie Institution from 1954 to 1956, he and a colleague discovered radio emissions from Jupiter. Franklin joined the staff of the Hayden as assistant astronomer, serving as chairman of the Hayden and the Museum of Natural History's Department of Astronomy from 1972 to 1974. From 1956 to his retirement as the planetarium's chief scientist in 1985, his duties included presenting, and often writing, many sky shows. Franklin also taught popular and technical courses in astronomy several times a year. From 1973 to 1979, Franklin was public affairs officer of the American Astronomical Society. For two decades, he served in the AAS' Harlow Shapley Visiting Lecturer Program, visiting one or two colleges a year. Franklin was astronomy editor of T he W orld A lm aAmateur Astronomers Association 1010 Park Avenue New York, NY 10028

nac fr om 1970 to 1995, a nd fr om 1980 to 1992 pr ovided all astronomical calculations for T he Farm ers' A lm anac. He contributed daily information to T he N ew York Times fr om 1975 to 1997. As a columnist fr om 1983 to 1997, Franklin originated and wrote the weekly Sky Watch feature in The Times' science section. As a tribute to Franklin, Asteroid Number 2845 is named Franklinken in his honor.

Amateur Observers Sought
NASA's Dawn mission is getting ready to launch (no earlier than July 7) and head to the asteroids Vesta and Ceres (http://dawn.jpl.nasa.gov). The Amateur Observers' Program will observe the asteroids. Amateur astronomers are invited to make observations of Vesta and submit sketches, animations, light curves, etc. Fortunately, Vesta is a fairly bright asteroid, which means from ideal locations, it's technically a naked-eye object and from other locations binoculars or a small scope is sufficient. Star charts are at http://dawn-aop.astro.umd.edu/ charts/index.shtml. Details about the Amateur Observers' Program are at http://dawn-aop.astro.umd.edu.

Forwarding and Address Correction Requested 12

First Class