Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.aaa.org/EyepieceFiles/aaa/2013_04_April_Eyepiece.pdf Дата изменения: Wed Oct 14 23:22:16 2015 Дата индексирования: Sun Apr 10 03:40:43 2016 Кодировка: Поисковые слова: comet hale-bopp

Journal of the Amateur Astronomers Association of New York
BREAKING NEWS:
MARTIAN SPACECRAFT LANDS IN NJ (April Fools!)

EYEPIECE
April 2013
Volume 61 Number 4 ISSN 0146-7662

Isaac Asimov Memorial "Debate About Nothing"
By Richard Brounstein

NASA ROVER FINDS CONDITIONS ONCE SUITED FOR ANCIENT LIFE ON MARS
WASHINGTON - An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes. Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon - some of the key chemical ingredients for life - in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month. " A f u n d a me n t a l question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters i n W a s h in g to n . " F r o m NASA's Curiosity Drills to Test what we know now, the Martian Surface Materials answer is yes." Clues to this habitable environment come from data returned by the rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine grain mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic, or extremely salty. The patch of bedrock where Curiosity drilled for its first sample lies in an ancient network of stream channels descending from the rim of Gale Crater. The bedrock also is finegrained mudstone and shows evidence of multiple periods of wet conditions, including nodules and veins. Curiosity's drill collected the sample at a site just a few hundred yards away from where the rover earlier found an Ancient streambed in September 2012.
NASA Rover (con't on Page 5)

Imagine finding yourself in a room with a theoretical physicist, an experimental physicist, an astrophysicist, a cosmologist, a philosopher, and a science journalist. This must be an episode of The Big Bang Theory. But it's not - you're actually sitting with 1,500 other riveted audience members and thousands of online streaming viewers, as they all experience the AMNH 2013 Isaac Asimov Memorial Debate. This year's thought-provoking topic: "The Existence of Nothing." Your esteemed debate panelists: Eva Silverstein: Professor of physics at Stanford University and the SLAC National Accelerator Laboratory Lawrence Krauss: Foundation Professor in the School of Earth and Space Exploration and Director of the Origins Project at Arizona State University John Richard Gott, III: Cosmologist and professor of astrophysical sciences at Princeton Jim Holt: Philosopher, longtime contributor to the New Yorker, and writer on string theory, time, infinity, numbers, truth and nonsense (yes, nonsense, he says) Charles Seife: NYU professor of journalism, author, and theoretical mathematician

Moderating the debate was AAA's own Neil DeGrasse Tyson, Director of the Hayden Planetarium. Tyson created a relaxed atmosphere, describing this debate more as a "conversation that the scientists would have in a bar." (I wondered if that's the reason panelists were drinking their water out of wine glasses).
Debate About Nothing (con't on Page 3)


EYEPIECE

April 2013

WHAT'S UP IN THE SKY
AAA Observers' April Guide By Richard Rosenberg

Astronomical Fact of the Month

April's Evening Planets : Saturn is at opposition on April

28th. On this day Saturn rises in the east when the Sun sets. Jupiter gets lower during the month but is still gloriously bright. In the last week of April, Venus appears in the western twilight. constellations, now in the west, including Orion, Taurus the Bull, Auriga the Charioteer, the Dogs Canis Major and Canis Minor and Gemini the Twins. To find the stars of spring, look overhead to spot the Big Dipper. If we imagine a leak in its pot, its contents would land on Leo the Lion, containing the bright star Regulus. Returning to the Big Dipper and this time follow the arc formed by the pot's handle, we arrive at Arcturus in the constellation Bootes the Herdsman. Continuing along the arc takes us to Virgo, with its bright star Spica. low in the east. Mars is too close to the Sun. Fortunately, Saturn can be seen almost the entire night.

April' s Evening Stars: Still around are the brilliant winter

April's Morning Planets : Mercury will be difficult to spot

April's Morning Stars:

The spring constellations of Bootes, Virgo and Hercules are getting ready to set in the west. The Summer Triangle (with the constellations Lyra, Cygnus and Aquila and corresponding bright stars Vega, Deneb and Altair) is near the zenith. Sagittarius is very low but if you have a dark sky the view is magnificent. The autumn constellations in the east include Cassiopeia, Perseus, Pegasus and Andromeda.

Similarities abound in space. The Herschel and Spitzer telescopes have tagged bright stars Vega and Fomalhaut as kindred spirits. Sitting 25 light-years away from Earth, both have warm and cool asteroid belts separated by a gap, just as we have between Mars and Jupiter, and the Kuiper Belt's distant icy region beyond Neptune. Astronomers believe this stellar architecture suggests that multiple planets will be found between the belts in both systems. There are other similarities as well. Both stars are approximately twice the mass of our Sun, and burn a hotter, bluer, color in visible light. Both are around 400 million years old, but Vegas may be aging better, and actually be as much as 800 million years old. For now, Fomalhaut's main focus is its known extrasolar planet, Fomalhaut b, in its eccentric orbit at the inner edge of the system's NASA's Spitzer Space Telescope captures Vega cometary belt.
Nebula of the Month Eskimo Nebula NGC 2392

Asteroid Belts and Planets By Evan Schneider

April "Skylights"
April 3 April 10 April 14 April 17 April 18 April 20 April 22 April 24 April 25 April 27 April 28 Last Quarter Moon at 12:37 a.m. (EDT) New Moon at 5:35 a.m. (EDT) The Moon is 2.2° from Jupiter. Nearby is the bright star Aldebaran Mars is in conjunction with the Sun and passes into the morning sky. It will not be seen for several months First Quarter Moon at 8:31 a.m. (EDT) The Moon is 5.6° south-southwest of Regulus The Lyrid meteor shower peaks this morning The Moon is extremely close to Spica Full Moon at 3:57 p.m. (EDT). The Moon is 3.5° south-southwest of Saturn Saturn is at opposition Venus is getting far enough from the Sun to be seen

For additional information visit: www.aaa.org/month413

Winter - it's cold outside. It's even colder in space. But across the void, we look out onto a vast assortment of nebulae, burning at temperatures way beyond our 5,000K Sun. The Eskimo Nebula is in one such area of space, just 5,000 light-years from us its heated gasses reaching 30,000K. T h e d y in g s t ar , named for the image resembling a face in a fur parka, was discovered in 1787 by British astronomer William Herschel. NASA/Hubble's Wide Field and Planetary Camera 2 show us that the parka is actually a disk of stellar material with a ring of comet-like objects, their elongated tails trailing as they streak away from center of the planetary nebula. The ejected material travels at high speeds, up to 900,000 mph, on a journey outward that started about 10,000 years ago.

By Evan Schneider

2


EYEPIECE
Debate About Nothing (Cont'd from Page 1)

April 2013

Our contributors are all accomplished scientists and professors. Each has published one or more books relevant to the subject of "nothing". Laurence Krauss, for example, published A Universe from Nothing. Charles Seife published Zero: The Biography of a Dangerous Idea. Tyson asked the distinguished group to describe "nothing" any way they wished to interpret it. Sometimes, the conversation turned to mathematics, discussing the value "0." Other times, the discussion encompassed aspects of cosmology, multi-verses, and the birth of our universe. Most interesting, was listening to the panelists as they tried to imagine what "nothing" actual is, and what it may look like. HISTORY OF NOTHING Seife was quick to point out that the Greek and Roman civilizations refused to integrate a zero into their number scheme, unless absolutely necessary for calculations. This had more to do with a cultural desire to always have something and not to accept that there could ever be nothing. This also goes into the longtime belief that the universe has always existed. Remember - the Big Bang Theory was not created until the 20th century. Before then, few accepted that there was a time when there was no universe...when there was indeed nothing. Neil DeGrasse Tyson focuses his Over time, socieaudience on the concept of "Nothing" ties accepted our very useful mathematical placeholder, zero, and accepted the fact that there was once nothing when there was no universe. If not for this early hypothesis, advanced mathematics, and thus all engineering projects, would have been impossible to create without the value "zero." WHAT EXACTLY IS NOTHING? Each panelist was asked to define the term "nothing." Surprisingly, this is not an easy answer. Holt gave a thoughtprovoking reply: "If not the universe, then what?" He would have us imagine a sphere with a radius. Then imagine the radius shrinking to smaller and smaller sizes until it shrinks to zero. That is his "nothing." It was Gott, however, who gave a humorous, but effective interpretation. He put his hands over his eyes and said: "See that blackness. That is what nothing looks like. It is all black." He put his hands behind his head where he could not see them and said "This is what the universe looked like before the Big Bang. It is impossible to see." THE QUANTUM WORLD AND NOTHING After discussing the concept of nothing by eliminating all matter, eventually we fall into the quantum world and how even the vacuum of space is still something that is not "nothing." Silverstein joined the conversation, pointing out that shrinking the radius of a sphere to nothing does not take into account all the chaotic behavior of matter in the quantum world. In addition, she queried, quantum mechanics and String

Theory can provide a unique solution to the concept of "nothing." String Theory requires 10 spatial dimensions of matter. As we go back in time to the Big Bang, the special dimensions disappear and we eventually approach "nothing." CAUSE AND EFFECT Holt pointed out how cause and effect are important when determining the origins of the universe. He would ask "What is the First Cause?" As you go back in time to the cause of every state of matter, at some point you get to the first cause that resulted in matter. At some point, therefore, matter must have been created from nothing. WHY DOES OUR UNIVERSE EXIST AT ALL The discussions bordered on both philosophical and scientific perspectives. Krauss explained that only religion needs a creation theory of how something had to exist to create the universe out of nothing. Science accepts the concept of a universe created from nothing. This follows the Anthropic Principle, allowing the universe to be possible because we are here - very comforting even if it is self-centered for humans. Holt added that our universe is also very imperfect. He just does not understand what the creator was thinking, telling the audience "It looks like it was made in a lab by hackers." FINAL THOUGHTS ON NOTHING Most scientists did agree that "nothing" simply means that there is not anything there. Seife provided a mathematical description: Start with 0. Remove it and you get the null set. That is nothing. Silverstein, taking the most technical scientific posture, defined "nothing" as the "ground state of a gapped quantum system." In the end, it was certainly "something" of an evening.

And the Winner of the Largest-Known Spiral Galaxy Contest Is...
NASA: The spectacular barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now, a team of astronomers from the United States, Chile and Brazil has crowned it the largest-known spiral, based on archival data from NASA's Galaxy Evolution Explorer (GALEX) mission. Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy. The galaxy's unusual size and appearance stem from its interaction with a much smaller disk galaxy named IC 4970, which has only about one-fifth the mass of NGC 6872. The odd couple is located 212 million light-years from Earth, in the southern constellation Pavo.
3


EYEPIECE

April 2013

Become a AAA Spring Starfest Team Member
Member Volunteers Needed
The AAA Spring Starfest is finally here! Come join your fellow amateur astronomers as we support our club and all of NYC. Volunteer opportunities are open to all members, their families, and even non-members.

Wanted: Event Night Staff
1 Experienced photographer 1 Writer/Tweeter/ blogger 10 Raffle tables staff members 10 Event staff members to set-up/ break down and distribute hand-outs (must be able to lift 15 lbs.) 2 Runners

Our AAA Gift to You
All staff volunteers will receive a special event "Limited Edition" T-shirt
Our Location: Woodlawn Cemetery is a national historic landmark that has commanding open area views, free of glare from local lighting, where the majority of the urban night sky can be seen. There will be telescopes of various magnifications and design, capable of reaching out into the Milky Way galaxy and beyond. Come have a look at the universe from the Bronx. Our Targets: Our astronomical targets will be both near and far. In our solar system, the cloud bands of Jupiter, its moons, and our Moon will be easily visible. Beyond, we will observe distant galaxies, star clusters, and nebulae. The sky is filled with opportunities each night. Directions: Enter at the Jerome Ave. entrance located one block north of the intersection of Jerome Ave. & Bainbridge Ave. Look for a table staffed by AAA members.
4

For more information and to join the AAA team
Contact: Susan Andreoli at vp@aaa.org VISIT THE AAA STORE for NEW STARFEST EVENT ITEMS
www.cafepress/amateurastronomersofny


EYEPIECE

April 2013

A Message from AAA President Marcelo Cabrera
Hello Members: I hope you saw comet Pan-STARRS in March. I was able to see it at our Winter Astronomy Class 2013. We had a fun night, and most students got to observe the comet from high above midtown Manhattan. On April 13, we will have our first Spring Starfest "live" from Woodlawn Cemetery. It will kick off the AAA observing season. For more information, visit the AAA website at: http://www.aaa.org/springstarfest. Be sure to check out more about our observing sites at http://www.aaa.org/observing, and see our full calendar of events at http://aaa.org/calendar. For our AAA Lecture Series at the AMNH, we have jus announced a surprise guest speaker. Al Nagler from Tele Vue Optics and inventor of the Nagler Eyepiece will present "Giant Eyepieces That Swallow Spacecrafts" on Friday, April 5. The balance of this season's schedule is available at http://www.aaa.org/lectures1213, or at the back of this issue of Eyepiece. We are currently interviewing candidates for the Board of Directors of the AAA. If you would like to be considered, please contact me at president@aaa.org. Thanks, everyone!

Sincerely,

NOTICE: AAA Annual Meeting May 15, 2013 - 6:00 p.m. - 9:30 p.m. 505 Eighth Avenue, 20th Fl Food, Fun, and Astronomy!

Contacting AAA Marcelo Cabrera President, AAA
NASA Rover (con't from Page 1)

Membership: members@aaa.org Eyepiece: editor@aaa.org General Club Matters and Observing: president@aaa.org

Telephone: 212-535-2922

Website: www.aaa.org

these results for several of the trace gases analyzed by the "Clay minerals make up at least 20 percent of the compoSAM instrument. sition of this sample," said David Blake, principal investigator "We have characterized a very ancient, but strangely new for the CheMin instrument at NASA's Ames Research Center 'gray Mars' where conditions once were favorable for life," in Moffett Field, Calif. said John Grotzinger, Mars Science Laboratory project scienThese clay minerals are a prodtist at the California Institute of uct of the reaction of relatively fresh Technology in Pasadena, Calif. water with igneous minerals, such as "Curiosity is on a mission of discovolivine, also present in the sediment. ery and exploration, and as a team The reaction could have taken place we feel there are many more excitwithin the sedimentary deposit, during discoveries ahead of us in the ing transport of the sediment, or in mo n t h s a n d y e a r s t o c o me . " the source region of the sediment. Scientists plan to work with The presence of calcium sulfate Curiosity in the Yellowknife Bay along with clay suggests the soil is area for many more weeks before neutral or mildly alkaline. beginning a long drive to Gale CraScientists were surprised to ter's central mound, Mount Sharp. find a mixture of oxidized, lessInvestigating the stack of layers exoxidized, and non-oxidized chemiposed on Mount Sharp, where clay cals providing an energy gradient of minerals and sulfate minerals have the sort many microbes on Earth been identified from orbit, may add exploit to live. This partial oxidation NASA's Curiosity at the "John Klein" site, taken with the information about the duration and Mars Hand Lens Imager (MAHLI) was first hinted at when the drill diversity of habitable conditions. cuttings were revealed to be gray NASA's Mars Science Laboratory Project has been using rather than red. Curiosity to investigate whether an area within Mars' Gale "The range of chemical ingredients we have identified in Crater ever has offered an environment favorable for microbial the sample is impressive, and it suggests pairings such as sullife. Curiosity, carrying 10 science instruments, landed seven fates and sulfides that indicate a possible chemical energy months ago to begin its two-year prime mission. NASA's Jet source for micro-organisms," said Paul Mahaffy, principal Propulsion Laboratory in Pasadena, Calif., manages the project investigator of the SAM suite of instruments at NASA's Godfor NASA's Science Mission Directorate in Washington. dard Space Flight Center. (Article Credit: NASA/Dwayne Brown, JPL/D.C. Agle) An additional drilled sample will be used to help confirm 5


EYEPIECE

April 2013

WHAT IF???

Can We Really Discover Gravity?
By Richard Brounstein

In March, scientists at the CERN Large Hadron Colthrough mathematics and not experiments. lider confirmed that the sub-atomic particle in the family of Boson particles known as the Higgs exists. They were pretty Our hope for the future is to someday confirm gravitasure last year (about 99.997% sure). That wasn't enough for tional theory and find experimental evidence. What if we can these quantum scientists. After going through several do more than just understand it? Science would prefer to affect petabytes of data, scientists are now calling the experiment a gravity in a practical way and not just by introducing mass to success. This is a huge accomplishment for science. The create a gravitational field. What if we could find the elusive Higgs particle is the messenger that creates mass in our uniGraviton (particle or string) and find a way to interrupt some verse. It is the reason that we have stuff from atoms and peoor all of its effect on matter? Science fiction stories have been ple to stars and galaxies. In the Standard Model of particle doing this for years. When you see people walking on the physics, this discovery checks off the list another critical point USS Enterprise in Star Trek, they walk in an artificial gravity particle in nature that is no longer theoretical, but is factual. field created by "gravity plating" on the floor. No one explains exactly how this magical floor works, but it makes it While the physics world is celebrating, we still have this much easier to work on a spaceship (as well as much easier to big elephant in the room. The Standard Model doesn't explain film stories). why a baseball, football, or spacecraft falls to the Earth. It What if we could someday does not explain gravity. create a device that can either interrupt gravity or enhance it To explain gravity, sciensomehow? How would this tists have a theoretical elemenshape our world of the future? I tary particle called the Graviton think the first invention people Boson. The Graviton communiwould want are anti-gravity cates the force of gravity just as devices on vehicles. We could the Higgs Boson communicates finally have flying cars just like the mass of our existence. We on "The Jetsons" or "Back to experience gravity everywhere the Future P2". Parking would in the universe, so something still be a problem for your flymust exist. Yet no quantum ing car even if no longer had to experiment has found it, leaving sit in traffic. Not every problem us with just a theory. is gravity's fault. We could One might think that all NASA/ESA concept drawing for LISA have everything flying much we have to do is discover this Trapping gravity waves in space more easily: skateboards, jet messenger particle with an acpacks, cars, and more. I want to celerator, the same way that scientists discovered the Higgs see someone run a marathon in anti-gravity shoes. We won't Boson, right? Unfortunately, the Standard Model cannot fit count their finish time. It would just be an experiment. Offithe Graviton Particle into its theory because its energy apcial athletes must use the natural gravity field. proaches infinity. Getting into outer space would no longer cost $10,000 a There are other more cost effective efforts under way to pound. We could get into orbit with much larger machines better understand gravity. NASA/ESA's Laser Interferometer using much less fuel, and land on Earth as easily as a helicopSpace Antenna (LISA) consists of three spacecraft positioned ter lands on a platform. five million kilometers apart in outer space. Each probe will Landing on Mars would also be much less of a challenge. maintain a constant laser beam shot at the other two detectors. The very impressive Curiosity landing was a great feat of engiIt would detect the ripple of gravity waves created by black neering. Just attach our anti-gravity device and use a small holes or stellar collisions. This will help confirm Einstein's rocket to land a 50 ton habitat on Mars, and we're ready to let General Theory of Relativity, and may even produce direct scientists do the work. I also want regular deliveries of supmeasurements of the Big Bang. We haven't seen the light at plies for the same price as shipping them across the oceans the moment of the Big Bang yet, but gravity waves may be here on Earth. We would have a self-sufficient Martian colony detectable, bringing us closer to the single most important up and running in just a few years. event in the known history of the universe. This does not actuSomewhere out there is the illusive Graviton (wave, parally help us find the elusive Graviton, but it is a step in the ticle or string). We will keep searching for it, since we know right direction. something must exist. I think of it every time I step on the Another effort to explain gravity is String Theory, where scale and dream of losing 10 pounds. If you need me, I will be all matter is made up of tiny one-dimensional oscillating lines at the gym fighting gravity. of energy that exist in 10 spatial dimensions. It can describe
the Graviton as a type of string with its unique properties. Problem solved, except that it is only a theory expressed 6
Richard Brounstein's monthly column, "WHAT IF," explores what today seems improbable or impossible. Stay tuned for more fascinating concepts.


EYEPIECE

April 2013

AAA BRIEFS IN ASTRONOMY
Faster Than a Speeding Bullet
new study using observations from NASA's Fermi Gamma-ray Space Telescope reveals that expanding debris of exploded stars produces some of the fastest-moving matter in the universe. This discovery is a major step toward understanding the origin of cosmic rays, one of Fermi's primary mission goals. "Scientists have been trying to find the sources of high-energy cosmic rays since their discovery a century ago," said Elizabeth Hays, from NASA's Goddard Space Flight Center. "Now we have conclusive proof supernova remnants, long the prime suspects, really do accelerate cosmic rays to incredible speeds." Cosmic rays are subatomic particles that move through space at almost the speed of light. About 90% of them are protons, with the remainder consisting of electrons and atomic nuclei. In their journey across the galaxy, the electrically charged particles are deflected by magnetic fields. This scrambles their paths and makes it impossible to trace their origins directly. Through a variety of mechanisms, these speedy particles can lead to the emission of gamma rays, the most powerful form of light and a signal that travels to us directly from its sources. The Fermi results concern two particular supernova remnants, IC 443 and W44, which scientists studied to prove supernova remnants produce cosmic rays. IC 443 and W44 are expanding into cold, dense clouds of interstellar gas. These clouds emit gamma rays when struck by high -speed particles escaping the remnants. Scientists previously

Spin Doctors at NASA
Two X-ray space observatories, NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency's XMM-Newton, have teamed up to definitively measure the spin rate of a black hole with a mass two million times that of our sun. The supermassive black hole lies at the dust and gas-filled heart of a galaxy called NGC 1365, spinning almost as fast as Einstein's theory of gravity will allow. The observations are a powerful test of the theory, which says gravity can bend space-time, the fabric that shapes our universe, and the light that travels through it. "We can trace matter as it swirls into a black hole using X-rays emitted from

A

could not determine which atomic particles are responsible for emissions from the interstellar gas clouds. After analyzing four years of data, Fermi scientists see a distinguishable feature in the emissions of both remnants. The feature is caused by a short-lived particle called a neutral pion, produced when cosmic ray protons smash into normal protons. The pion quickly decays into a pair of gamma rays, emission that exhibits a swift and characteristic decline at lower energies. The low-end cutoff acts as a fingerprint, proving that the culprits in IC 443 and W44 are protons. "The discovery is the smoking gun that these supernova remnants are producing accelerated protons," said Stefan Funk, an astrophysicist with the Kavli Institute for Particle Astrophysics. "Now we can work to better understand how they manage this feat and determine if the process is common to all remnants where we see gamma-ray emission."

regions very close to the black hole," said NuSTAR principal investigator Fiona Harrison of the California Institute of Technology. "The radiation we see is warped and distorted by the motions of particles and the black hole's incredibly strong gravity." NuSTAR, an Explorer-class mission launched in June 2012, is designed to detect the highest-energy X-ray light in great detail. It complements telescopes that observe lowerenergy X-ray light, such as XMM-Newton and NASA's Chandra X-ray Observatory. Scientists use these and other telescopes to estimate the rates at which black holes spin. Until now, these measurements were not certain, because clouds of gas could have been obscuring the black holes and confusing the results. With help from XMM-Newton, NuSTAR was able to see a broader range of X-ray energies and penetrate deeper into the region around the black hole. The new data demonstrate that X-rays are not being warped by the clouds, but by the tremendous gravity of the black hole. This proves that spin rates of supermassive black holes can be determined conclusively. Measuring the spin of a supermassive black hole is fundamental to understanding its history and that of its host galaxy. "These monsters, with masses from millions to billions of times that of the Sun, are formed as small seeds in the early universe and grow by swallowing stars and gas in their host galaxies, merging with other giant black holes when galaxies collide, or both," said Guido Risaliti of the HarvardSmithsonian Center for Astrophysics, and the Italian National Institute for Astrophysics. Supermassive black holes are surrounded by pancake-like accretion disks, formed as their gravity pulls matter inward. Einstein's theory predicts the faster a black hole spins, the closer the accretion disk lies to the black hole. The closer the accretion disk is, the more gravity from the black hole will warp X-ray light streaming off the disk. 7


EYEPIECE

April 2013

WHY WE EXPLORE NASA Mission: Kepler to Universe: "Is There Anybody Out There?"
By Amy Wagner
"We find ourselves at a special moment in time for scientific discovery ­ as with Christopher Columbus, the Apollo Moon Missions, and the Human Genome Project ­ there is a sense in the air that we are on the brink of a breakthrough. The breakthrough within our grasp is the discovery of life elsewhere in the universe. We're very close."
Geoff Marcy - Co-investigator/Kepler Mission

Geoff Marcy has discovered more extrasolar planets than anyone - over 250 so far. On March 11, he presented "Other Earths and Life in the Universe," to a breathless audience at the AMNH Frontiers Lecture Series. Marcy, a key planet hunter with the NASA Kepler Space Telescope Mission, works to detect exoplanets, characterize their properties, and understand their origins. His current focus is on finding Earth-size planets and solar systems similar to our own. The transit method of detection measures the change in brightness of a star when a planet has passed in front of it. It is harder to detect small, Earth-sized planets, because their transits result in only a tiny decrease in light received. Typically, their host star's brightness drops by only 0.01% during a tran-

Brightness drops over time as an exoplanet transits its star
(Illustration by Hans Deeg)

sit. That's where Kepler comes to the rescue. Launched on March 9, 2009, the telescope is especially suited to detecting Earth-sized planets. It has the ability to measure brightness to within 0.01%. Perfectly suited for this assignment. Trailing behind Earth in a solar orbit, Kepler continuously observes the same field of stars, pointing to the constellations Cygnus, Lyra, and Draco. To date, nearly 3,000 exoplanets have been found with the help of the Kepler Observatory. Of those, over 100 are Earth-like in size. One such "Other Earth" is Kepler-10b, the first confirmed terrestrial planet discovered outside our solar system. Kepler-10b's transit dims its host star's light by about 0.01% every 0.84 days. The transit method can tell alot about a planet. If we know the radius of a star, then we can find the radius of a transiting planet based on the fraction of light it 8

blocks. Calculations show Kepler-10b's radius is 1.4 times that of Earth. From radius and orbital period, we can measure the distance of the planet from its star and its temperature: the longer the orbital distance, the cooler the planet. Kepler-10b lies extremely close to its star, too hot to support life. Surface temperature on its star-lit side is approximately a blazing 2800°F. Kepler 10-b may Kepler's final inspection be lifeless, but it has before its 2009 launch given life to a new field of science, "astrogeology." Scientists have learned a great deal about the exoplanet. In addition to size and temperature, we also know its mass, density, and composition. To determine mass, scientists turned to the W.M. Keck Observatory in Hawaii. The Keck measures the wobble of a star due to gravitational pull from an orbiting planet. Wobbles are variations in the star's radial velocity, or the speed with which it moves towards or away from Earth, and show up as displacements in a star's spectral lines due to Doppler Effect. Keck can observe extremely small radial-velocity variations to one in 1,000 pixels. While the Doppler method cannot determine a planet's true mass, it can set a lower limit on it. Kepler-10b wobbles in sync with its star, and its mass is about 4.5 times that of Earth. Knowing mass and volume (from its radius), Kepler-10b's density is calculated as 8.8 g/cm3. The density of Earth is 5 g/ cm3, so surely this planet is rocky! Marcy ranks the discovery of Kepler-10b "as among the most profound scientific discoveries in human history," and predicts the planet "will go into every textbook worldwide." Very few Earth-sized exoplanets have been discovered. Kepler can't see them all because of their small size, and because the telescope's fixed view only sees planets that orbit edge-on. Investigators had to correct for the limitations of Kepler and created new software to test the efficiency of its findings. With that efficiency factored in, Marcy reported brand new data, yet to be published, which reveals that 23% of Sun-like stars have planets with sizes ranging from 1-3 times the radius of the Earth and that orbit within 0.25 astronomical units of their host stars. Earth-sized planets are not just common in our universe, they are typical. What about life? Can Kepler tell us if there are other
Kepler to Universe (con't on Page 9)


EYEPIECE
Kepler to Universe (con't from Page 8)

April 2013

Earths could be 10 billion years old; perhaps their technointelligent life died out long ago. Also, the lifetimes of adhabitable planets out there, and if so, how many could there vanced civilizations must overlap for communication between be? In a breathtaking paper published in February this year, them, and maybe, we missed the window. Or for those that Harvard graduate student Courtney Dressing calculated the lived contemporaneously and communicated with each other, occurrence of habitable planets in our universe. From the Keit is possible that their contact was not amicable; they may pler data, she looked at systems with red dwarf stars, the most have destroyed each other. And of course, there is the possicommon type in our universe. Three out of every four stars in bility that they destroyed themselves. the Milky Way galaxy are red dwarfs. They are small stars, "The takeaway message is this," says Marcy, "Take care and an Earth-sized planet would block more of its light during of our planet; take care of ourselves." transit. Red dwarfs are also cooler and more likely to host planets with habitable zones. After targeting just red dwarfs, It is only through the continued work of the Kepler Space Dressing honed in on 95 planetary candidates, showing that at Telescope and investigators like Geoff Marcy that we can we least 60% of red dwarfs have orbiting planets smaller than hope to learn how to take care of our planet or find neighbors Neptune. Of this sample, three had the right conditions to supwho will talk to us. Unfortunately, we may be running out of port life based on size, temperature, and orbital distance. From time. Kepler could die on us any day now. Although NASA this, she extrapolated that 6% of the 75 billion red dwarf stars added another four years to Kepler's initial four-year mission, in the Milky Way must have Earth-sized planets that orbit in a one of its four reaction wheels has already failed; another is habitable enough distance to allow liquid water to exist. showing signs of friction. Our Sun is surrounded by a swarm of red dwarf stars, and It is sad to think that we could lose Kepler so soon; howusing Dressing's calculations, the closest Earth-like world is ever, this vital program has already produced so much data likely to be just 13 light-years away. "If the Milky Way Galthat we can hardly sift through it all. More than 400 multiaxy were the size of the U.S., then the nearest star with a habitplanetary systems have been discovered so far ­ the Kepler-11 able planet would be across Central Park," said Marcy to the system alone has as many as 6 planets orbiting its host star ­ Hayden audience. but there just aren't enough astronomers around to deal with all that information. So, what is the likelihood that habitable planets have produced not just life, but intelligent life? According to Marcy, However powerful and prolific telescope may be, its data even the most pessimistic calculations would predict thousands is meaningless without Marcy and other dedicated astronoof advanced civilizations in the Milky Way. Is our own galaxy mers. So, lend a hand with the Kepler project, you amateur teeming with intelligent life? If so, then why haven't they astronomers - join Planet Hunters - www.planethunters.com. called? SETI is trying to change all that, but no takers yet from intergalactic space. Life itself may be rare. Earth has water, but just the right amount, a thin veneer of 0.06%. Most rocky planets discovered are either desert worlds with only 0.03% water, or water worlds with 0.12%. "There may be fish there, but no smart people," jokes Marcy. Life could swim, but it wouldn't walk around. Earth's perfect water ratio may just have been a lucky delivery from asteroids and comets. Intelligence may also be rare. Does evolution necessarily select for techno-intelligent life? Dinosaurs lived over a million years without getting smarter. If it weren't for the mass extinction of those giant, birdbrained reptiles, sly little mammals would not have selected for evolutionary advancement. And for intelligent life out there, what is the typical lifetime of a civilization? Red dwarfs live longer than our Sun, so it is possible that life on their habitable planets would be Artist's concept of the red dwarf star CHRX 73 (upper left) and its companion CHRX 73 B in the foreground (lower right) weighing in at 12 Jupiter masses. CHRX 73 B is one of the smallest much older and much more evolved companion objects ever seen around a normal star beyond our Sun than life on Earth. These Other (Illustration Credit: NASA/ESA/)G. Bacon STScl) 9


EYEPIECE

April 2013

Comets, Comets, Comets...

A Date With Comet PanSTARRS
By Jason Kendall

On Thursday, Mar 14, I wanted to see the comet for the first time on my own. But more importantly, I wanted my wife, Donna, to share it with me. She had never seen a comet, and I have only seen a few. I'd always wanted to share the stars with her, especially a unique, 100 million-year orbit Oort Cloud starry messenger. So I left work early and bolted, right on schedule. The comet, however, knew no schedule other than its own. It was to pass over our heads just once, returning long after every nation I knew or ever will know will have passed away and been replaced by many, many more. This comet was visiting us from nearly the next star, and in its ice was held the dust of eons, the tiniest flecks of the origin of our Sun and Earth. So, I ran in from the subway, and we bundled up for the cold. Hurriedly, we tromped downstairs to get our telescope. The Sun was rapidly sinking lower in the sky, so I moved with deliberate speed. We loaded our equipment, and Donna suggested we also take the binoculars, a gift from a grand class. The electric cart hurdled down the street and up into the park at a breathtaking walking pace. We chatted, and realized that it was colder than we had thought. The Sun was only a hand above the horizon as we walked through Inwood Hill Park, hauling 200 pounds of observing equipment in what amounted to a race. You see, the clouds were also a factor this evening. Donna and I looked westward with concern, tracking several foreboding near-horizon clouds. We wondered if the cold and the two hours prep and takedown would be spoiled by an opaque condensation of water. As we arrived at Bear Rock Meadow, the Sun was just about to graze the horizon. Donna jumped on the binoculars, and started hunting. I built the 15" scope from the box, my fingers already burning from the freezing air and gusty winds. But it set up well, and it was now show time. Our hunt was on. The sky darkened, but the comet refused to be seen. It was hiding up in those low clouds. We had a 10° window above the horizon, holding steady. After going back and forth between the binocs and the scope, I found it. There it was, tail pointing away from the Sun, shimmering like a little fish in a reddish sea. I gave Donna the binocs right away, and there was an immediate peal of joy: "There it is! I see the comet!" I then found the comet in the 15" Obsession UC with a goodly 35mm Panoptic. And there it

was again. The 15 brought out the tail and brightened the nucleus, but it didn't h av e the striking division that you see in a deep photo. I switched to the 17mm Ethos eyepiece, and then it really shone. It was easy to focus on a dim star that was right next to it, 51 Pisces, so now I knew the focus. I could see dimming in the tail that made it look like two tails. The wind was picking up, or else I would easily have seen the brightening and dimming of jets and changes. It was bright and clear enough, but the scope wagged around under the wind. Donna peered intently at it during a calm wind moment, and she saw changes in brightness and possible movement. The comet had been seen, and we'd witnessed this little miracle. Now the wind was whipping us, getting much colder, as the comet dipped below the horizon. Though Orion came out from the clouds and Jupiter beckoned, we were spent and frozen. Not even five layers could keep us warm in the dark night air. Packing the scope always takes longer than you want, and it always takes longest in a cold wind. But off we went, and down through the woods, the sheltering trees now covering us as we returned to Earth. Donna was happy to get warmer, and we put the scope away slowly, making sure that every part was handled with care. Each part helped us see this winged interloper, and each was valuable. Ninety minutes after we saw PanSTARRS dip below the horizon, Donna and I were sharing drinks at the Piper's Kilt, our traditional afterobserving location. We toasted each other, and talked about this once in a lifetime experience. Walking home hand in hand we remembered something my uncle said at our wedding. A marriage is a story that tells the world what love is, that as we live together, we write our book of love. Going home, we realized that we'd just written a good chapter, thanks to an auspicious comet named PanSTARRS.

Kleegor 's Universe
By Joshua M. Erich, www.pixelatedparchment.com

10


EYEPIECE

April 2013

AMNH RESEARCH Project 1640 Astronomers Conduct First Remote Reconnaissance of Another Solar System Researchers have conducted a remote reconnaissance of a distant solar system with a new telescope imaging system that sifts through the blinding light of stars. Using a suite of high-tech instrumentation and software called Project 1640, the scientists collected the first chemical fingerprints, or spectra, of this system's four red exoplanets, which orbit a star 128 light-years away from Earth. A detailed description of the planets ­ showing how drastically different they are from the known worlds in the universe - was accepted for publication in The Astrophysical Journal. "An image is worth a thousand words, but a spectrum is worth a million," said lead author Ben R. Oppenheimer, AMNH associate curator and chair of the Astrophysics Department. Oppenheimer is the principal investigator for Project 1640, which uses the 200-inch Hale telescope at the Palomar Observatory in California (see image at right). The project involves researchers from the California Institute of Technology, NASA/JPL, Cambridge University, NYU, and the Space Telescope Science Institute, in addition to Oppenheimer's team at the Museum. The planets surrounding the star of this study, HR 8799, have been imaged in the past. But except for a partial measurement of the outermost planet in the system, the star's bright light overwhelmed previous attempts to study the planets with spectroscopy, a technique that splits the light from an object into its component colors - as a prism spreads sunlight into a rainbow. Because every chemical, such as carbon dioxide, methane, or water, has a unique light signature in the spectrum, this technique is able to reveal the chemical composition of a planet's atmosphere. With this system, the researchers are the first to determine the spectra of all four planets surrounding HR 8799. "It's fantastic to nab the spectra of four planets in a single observation," said co-author Gautam Vasisht, an astronomer at JPL. The results are "quite strange," Oppenheimer said. "These warm, red planets are unlike any other known object in our universe. All four planets have different spectra, and all four are peculiar. The theorists have a lot of work to do now." One of the most striking abnormalities is an apparent chemical imbalance. Basic chemistry predicts that ammonia and methane should naturally co-exist varying quantities unless they are in extremely cold or hot environments. Yet the spectra of the HR 8799 planets, all of which have "lukewarm" temperatures of about 1340 degrees Fahrenheit, either have methane or ammonia, with little or no signs of their chemical partners. Other chemicals, such as acetylene, previously undiscovered on any exoplanet, and carbon dioxide may be present as well. The planets also are "redder," meaning that they emit longer wavelengths of light, than celestial objects with similar temperatures. This could be explained by significant but patchy cloud cover on the planets. With1.6 times the mass and five times the brightness, HR 8799 itself is very different from our Sun. The brightness of the star can vary by as much as 8 percent over a period of two days and produces about 1,000 times more ultraviolet light than the Sun. All of these factors could impact the spectral fingerprints of the planets, possibly inducing complex weather and sooty hazes that could be revealed by periodic changes in the spectra. More data is needed to further explore this solar system's unusual characteristics. "The spectra of these four worlds clearly show that they are far too toxic and hot to sustain life as we know it," said co-author Ian Parry, a senior lecturer at the Institute of Astronomy, Cambridge University."But the really exciting thing is that one day, the techniques we've developed will give us our first secure evidence of the existence of life on a planet outside our solar system." Project 1640 helps scientists clear this hurdle by sharpening and darkening a star's light. This technical advance involves the coordinated operation off our major instruments: the world's most advanced adaptive optics system, which can make millions of tiny adjustments to the device's two 6-inch mirrors every second; a coronagraph that optically dims the star but not other celestial objects in the field of view; an imaging spectrograph that records 30 images in a rainbow of colors simultaneously; and a specialized wave front sensor that distinguishes between residual starlight that sneaks through the coronagraph and the light from planets, allowing scientists to filter out background starlight more effectively. Altogether, the project has produced images of celestial objects 1 million to 10 million times fainter than the star at the center of the image, with only an hour of observations. It is also capable of measuring orbital motion of objects. "Astronomers are now able to monitor cloudy skies on extrasolar planets, and for the first time, they have made such observations for four planets at once," said Maria Womack, program director for the Division of Astronomical Sciences at the National Science Foundation. "This new ability enables astronomers to now make comparisons as they track the atmospheres, and maybe even weather patterns, on the planets." 11


EYEPIECE

April 2013

FOCUS ON THE UNIVERSE Comet Chasing: Photographing PanSTARRS
By Stan Honda
wasn't expecting to dodge cow chips while photographing Comet PanSTARRS. Running across the high desert floor and carrying my camera, telephoto lens and tripod, I was trying to get a better angle on the comet and a beautiful crescent moon as they set behind the giant dish antennas of the Very Large Array (VLA) radio telescope. I had come to the clear skies of New Mexico to shoot the celestial pairing, which would only happen on Mar 12-13. A forecast of rain and cloudy weather for those days in New York made the decision easier. Landing in Albuquerque, I met my astronomy/photographer friend Rush, who suggested that the VLA in central New Mexico would make an interesting foreground for the photos. We set off after lunch, arriving in the late afternoon after a two-hour drive to the south. The observatory, located on the Plains of San Agustin near the town of Magdalena, is large and flat, and, at 6,500 feet, the perfect place for radio astronomy. The array was featured in the 1997 movie "Contact," based on Carl Sagan's novel of the same name. Jodie Foster's character uses the antennas to search the cosmos for evidence of other civilizations as part of the SETI program, and detects signals from the star Vega - indicating intelligent life outside our solar system. Up close, the 25-meter wide antennae are just as impressive as anything Sagan or Hollywood could dream up, especially in the waning desert light. We took a short walking tour around one of the dishes, with the idea of trying to line up the antennas with the setting comet and Moon. The land around the telescopes had been used for cattle grazing, so memories of the small piles of cow manure seen while scoping out the site flashed through my mind as the evening light faded. It turned out that avoiding the stinky piles was the easy part ­ spotting the comet was much harder. But the really great thing about the universe is that many events happen in a very predictable way. Articles and charts described Pan12

I

STARRS and the moon to be at about the same altitude and about 5° apart on Mar 12. After spotting the thin crescent Moon about 30 minutes after sunset, we looked to the left with binoculars ­ but found emptiness. I framed the Moon in the right side of my camera's viewfinder while using a 300mm lens, which has an angle of view of around 8°. So I knew that somewhere in the picture would be the comet. Some might wonder why we didn't use one of the new iPhone/smartphone astronomy apps. Well, we didn't have any apps, and neither of us had a smartphone. But we did have digital camera technology to help us. I kept shooting photos and checking the screen on the back of the camera. Around 7:50 p.m., over 45 minutes after sunset, I finally spotted the comet on the camera screen, its bright head and short, conical-shaped tail pointing away from the Sun. So we finally knew it was out there. Rush tried hard to see it in the binoculars, but was unable to resolve it in the dark New Mexico night. It still took many long minutes for the sky to fully darken, and for PanSTARRS to become more visible in the photos. In pictures, the earthshine that lighted the "dark" part of the moon was incredible. The super-thin, lit portion of the upturned crescent seemed to hold up the rest of the moon. Together with the comet it made for a breathtaking photographic image. Exposing for the comet and Moon was tricky. The process involved taking a light meter reading of the sky around the Moon, tak ing a photo, looking at the screen on the back of the camera, and making adjustments based on what I saw. To be consistent, I used f5.6 and an ISO 800, varying the shutter speed to get the right exposure. The times ranged from 1/25 of a second, when we first spotted the comet, to 8 seconds as it set beyond the horizon. I used a cable shutter release so I wouldn't jar the tripod mounted camera and lens. This was helpful during longer exposures. Comet Chasing (con't on Page 13)


EYEPIECE

April 2013

Comet Chasing (con't from Page 12)

The lenses I relied upon were a 300mm f4 and 70200mm f2.8 zoom. With the 300mm it was easy to get both the comet and the Moon in one picture. It's a relatively small and light lens that travels well. A longer telephoto lens would have been better for just the comet, but I was interested in seeing it in context with the Moon and the landscape. The zoom lens worked for slightly wider angle shots but as the focal length decreased, the comet got progressively smaller in the frame. On the first evening of shooting, my attention was focused on the western horizon. About 8:15 p.m., I caught a glimpse of lights to my left. Looking up to the south, I saw a dense field of stars against an inky black sky. Wow! I turned east and saw even more stars. It was only over an hour after sunset, yet we were seeing one of the darkest skies we had ever experienced. I had an urge to shoot some wide-angle shots of the unusually vivid sky, but the comet and Moon were setting rapidly in the west. After the lighted portion of the crescent Moon set, the camera picked up the "dark" part of the orb lit by earthshine. So an eerily dark Moon appeared to be peeking up from behind one of the distant mountains - great impact on the photographic composition.

frames might show it off well. In all, it was an extremely productive trip. Rush and I agreed that both nights were successful. Of all the celestial events, comets attract a great deal of attention. Maybe the potential of observing a truly spectacular object in the sky stirs their curiosity. For me, capturing the images of PanSTARRS was a truly memorable event ­ to visit just for a while with this icy ball hurling through space on its long elliptical orbit around the Sun, and then back out into the dark void of space.
Stan Honda is an accomplished professional photographer and contributing writer. In this continuing series of articles, he shares his extensive knowledge of photographic equipment and techniques. (All photo credits: Stan Honda, 2013; www.stanhonda.com )

Our adventure continued on March 13. Rush suggested we go west of Albuquerque to check out an area of lava flows. The ranger at the El Malpais National Conservation Area had heard of the comet and gave us of good viewing locations. We hiked up a small bluff that gave us a sweeping view of the long -dormant lava bed below us. We also could see a second bluff with trees that had the potential to create a nice foreground object if the comet lined up with it. We knew the Moon was supposed to be higher in the sky in relation to the comet, but instead it seemed to be much farther away. That made spotting the comet even harder. I finally thought I saw it through the 300mm lens, and confirmed that with a photo. As the sky darkened, I actually could see it with my eyes, as long as I knew exactly where to look. It was truly faint and fuzzy, like a nebula or galaxy. It seemed to be on its way to becoming a naked-eye object, though still quite faint. Once again, I was able to shoot the comet all the way to the horizon using a variety of lenses. I took a few photos with wide-angle lenses, which resulted in great scenery, but small images of the comet. Still, a large print of one of those

13


EYEPIECE

April 2013

Wanted: Writers for "My Own Space"
Dear Readers: In our March issue of Eyepiece, AAA board member Jason Kendall shared a touching story with us - his experience with the night sky in "Counting the 107." This unique perspective got me thinking. We all have memories of our first encounter with space. It may have been through the eyepiece of a telescope - the first time Jupiter came into focus and its four Galilean moons were seen in an aligned orbit. Or maybe it was that first trip to the Hayden Planetarium as a student, looking up at the projected, twinkling "Moonset "over the Petrified Forest (Photo Credit: Stan Honda, 2011) stars, and flying through the universe from the comfort of your cushioned seat in the darkness. So many of us have been there in our lifetimes. Some of you have been fortunate enough to travel great distances to observe the aurora borealis, its shimmering glow floating across the sky. Many have seen total eclipses of the Moon and Sun far away from the bright lights of New York City. Eyepiece writer and night sky photographer Stan Honda has stood under the Milky Way in the Grand Canyon and the Petrified Forest, pointing his camera up at the heavens to record its beauty. His story is told through his stunning photographs and Eyepiece articles. As an amateur astronomer, I was in awe at my first glimpse of Jupiter, of Venus, and that very first time I stood on my front porch in NJ, viewing Saturn and its tilted rings through my refractor, some 650 million miles away. Wow. Touching another planet with my eyes was a close encounter I will never forget. My visit to Saturn was just three years ago, when I joined AAA and bought my first starter scope. Standing in that same spot one cold morning after the Hurricane Sandy blackout, I looked up at thousands of stars, all waiting there to be seen, but forever blanketed by the cold night lights of Long Branch. We are missing so much due to light pollution. Space is personal to each of us. Some have goals to view as many distant targets as possible. Others share their love of astronomy by hosting observing sessions with both members and total strangers. For me, I accepted stewardship of Eyepiece so that I could touch a broad wealth of information each month and share it with you - NASA missions, the development of major earthbound telescope arrays, and the exciting exoplanet research of the Kepler mission. I marvel at the vastness of space, at the incredible distances between astronomical bodies, and at the immense power of supernovae and quasars. We float through space on our tiny blue planet, and the incredible universe around Jupiter and Moons (Photo Credit: Mike Hankey) us is alive with untold wonder. So, my fellow members, I would like you to join us at Eyepiece, just for awhile. Look inside yourselves, and give us your thoughts on what space and astronomy has meant to you. Share a personal experience, and we will publish your perspective on this page called "My Own Space." I hope that many of you take up this challenge - to relive some of your special memories, and to remind yourselves why you still get goose bumps each time you look up at the night sky.

Evan
Evan B. Schneider, Editor
14


EYEPIECE

April 2013

AAA Events on the Horizon
April 2013
Friday, April 2, 9, 16, 23, 30 Dusk - 10:00 p.m., P,T,C Observing on the High Line - Manhattan Next Month: May 7, 14, 21, 28 Thursday, April 11 6 p.m. - 8:00 p.m., M Seminar on Recent Advances in Astronomy - Manhattan 4 Washington Place (NYU) Next date: May 2 Friday, April 12 7 p.m. - 10:00 p.m., P,T,C Observing in the Bronx - Van Cortlandt Park Next date: May 10 Saturday, April 13 2 p.m. - 4:30 p.m., P,T,C Solar Observing in the Bronx - Woodlawn Cemetery Next date: May 11 Saturday, April 13 7 p.m. - 10:00 p.m., P,T,C Spring Starfest in the Bronx - Woodlawn Cemetery Next date: May 11 Friday, April 19 7 p.m. - 10:00 p.m., P,T,C Observing at Floyd Bennett Field­ Brooklyn (new location) Next date: May 17 Friday, April 19 8 p.m. - 11:00 p.m., P,T,C Observing at Carl Schurz Park - Manhattan Next date: May 17 Sunday, April 28 1 p.m. - 3:00 p.m., P,T, C Solar observing in Central Park, at the Conservatory Water Next date: May - To be announced on AAA website Please confirm all events at www.aaa.org/events before attending
Legend for Events: M: Members; T: Bring telescopes, binoculars, etc. P: Open to the public C: Cancelled if cloudy

Io's Shadow Transits Jupiter Seeking PanSTARRS By Joe Fedrick
I watched the shadow of one of Jupiter's moons, Io, transit the planet Jupiter on the evening of Mar 4-5. The shadow was barely visible in my 60mm achromatic refractor at 100x. The cloud belts of Jupiter have changed little since January - there were two main brownish equatorial belts and a moderately prominent, but fading, north temperate belt. Several fainter gray, barely discernible, belts were present at high latitudes. In sharp contrast to Io's smaller shadow, the shadow of Jupiter's largest moon, Ganymede, was much easier to detect with my 60 mm refractor on the night of Jan 10-11. I was out observing the crescent Moon in March, a thin curved, silver thread with beautiful earthshine above. The old Moon was in the new Moon's arms on the evening of Mar 13, as I attempted to locate the comet PanSTARRS in the urban night sky. Sunset was beautiful, but I had no luck from my viewing location in the Bronx. A hill to the west and southwest obstructed the horizon, where the comet was streaking toward its close encounter with the Sun. I hope to have news for you all next month, if I am able to find higher ground for my observations.
Joe Fedrick is an experienced and dedicated AAA observer, always watching the night (and daytime) skies. His continued observations bring us new dimensions to viewing the cosmos and solar activity.

AAA 2012/2013 Lecture Series Calendar
The AAA is proud to present an astronomy lecture series. Members and the public are welcome to attend. Admission is free, and no reservations or tickets are required. Lectures are held at the Kaufmann Theater, American Museum of Natural History, Central Park West between 77th and 81st streets (use 77th Street entrance). Lectures begin at 6:15 p.m. and run to 8:00 p.m.
Apr 5 Apr 26 Al Nagler, Founder, TeleVue Optics: "Giant Eyepieces that Swallow Spacecraft" National Technical Institute for the Deaf at RIT Astrodance at CUNY Graduate Center

Focus On: The Very Large Array - Socorro, New Mexico
Meet one of the largest radio telescope arrays in the world, the National Radio Astronomy Observatory. This compliment of 27 antennae, each 82 feet in diameter combines to produce the equivalent of a single antenna 22 miles wide. Telescopes are shuttled into various configurations every four months to perform different tasks. Look familiar? It was the facility used for the 1997 film "Contact," starring Jodie Foster.

Eyepiece Staff - March Issue
Editor: Evan B. Schneider
Writers: Richard Brounstein, Joseph Fedrick, Stan Honda, Jason Kendall, Amy Wagner Special Sections: Marcelo Cabrera, Joshua Erich, Edward Fox, Richard Rosenberg

NEXT MONTH IN EYEPIECE
Everything you want to know about astronomy and current events in space! Stay tuned, and read Eyepiece every month.

15