Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.aaa.org/EyepieceFiles/aaa/2011_10_October_Eyepiece.pdf Дата изменения: Sun Feb 22 20:31:02 2015 Дата индексирования: Sun Apr 10 03:43:17 2016 Кодировка: Поисковые слова: m 2

Journal of the Amateur Astrono mers Association of New York October 2011 Volume 59 Number 10 ISSN 0146 -7662

EYEPIECE
Earth, Juno will be the first solar power ed spacecraft to operate this far from the Sun. The 66 foot span of the three solar panels is designed to capture sufficient ener gy to operate all on board systems. To protect the sensitive electronics, Juno carries the first ever radiation shielded electronics vault. This design will be used for future missions in hostile environments. To protect against the build up of electrostatic charges while traveling through space, Juno utilizes lea ding edge design carbon nanotube -based sheet material, EMSHIELD, developed by Nanocomp Technologies in partnership with Lockheed Martin (www.spaceref.com/news/viewpr.html?pid=34312). By positioning the spacecraft in a polar orbit, it will be able to look down on the auroras, most likely created by charged particles ema nating from Io's volcanic emissions reacting with the Jovian atmospher e. A second area of inter est is measuring the a mount of water in the atmospher e. The University of Colorado Boulder has contributed to the Juno through mission co-investigator Professor Fran Bagenal of the Laboratory for Atmospher ic and Space Physics. "One of the biggest questions left after the Galileo mission was how much water there is in Jupiter's atmospher e," said Bagenal. "The amount of water is key, because water played a huge role in the for mation of the solar system. Most of us know that water absorbs microwaves. We are going to be using a microwave detector and fly just over the clouds of Jupiter, looking down at differ ent cloud depths to measure the amounts of water below. It's a bit like doing a CT scan of Jupiter's dense clouds." On the non-technica l side, Juno is also carrying three aluminum LEGO figures repr esenting Galileo and Roma n gods Juno and Jupiter. Ther e will also be a plaque in Galileo's honor, emblazoned with his likeness and his own handwritten notes concerning his observations of Jupiter's moons Contact with Jupiter bega n in1973 with the robotic space
Juno continued on page 3

NASA Ups the Ante - Juno Mission to Jupiter Launches
By Evan Schneider
Many of us have viewed Jupiter through our telescopes and astronomical binoculars. Our fifth planet from the Sun has captured the ima gination of a mateur astronomers and NASA over the years, and its latest $1.1 billion mission, Juno, a part of the New Frontiers Program will explore Jupiter from an entir ely differ ent perspective. On August 5th an Atlas V-551 rocket lifted Juno into space on its five year journey (see NASA's complete status and overview at www.nasa.gov/mission_pages/juno/ma in/ index.html). Understanding the origin and evolution of this gas giant will provide a new perspective of our solar system and newly discover ed planetary systems being studied by distant probes and ground/space based telescopes. "Jupiter is the Rosetta Stone of our solar system," said Scott Bolton, Juno's principal investigator from the Southwest Research Institute in San Antonio. "It is by far the oldest pla net, contains more material tha n all of the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going ther e as our emissary ­ to interpret what Jupiter has to say." Using a spinning, solar-power ed spacecraft to traverse the 1,740 million miles, Juno will make 33 eleven-day orbits. As with earlier Pioneer spacecraft, spinning ma kes the spacecraft's pointing stable and easy to control. Traveling within 3,100 miles of Jupiter's cloud tops, its mission will include ma king maps of the gravity, ma gnetic fields and atmospheric composition from a unique elliptical polar orbit and sampling its full range of latitudes and longitudes. Juno will carry precise highsensitivity radiometers, vector magnetometer, gravity/ radio science system, a six-wavelength microwa ve radiometer for atmospheric sounding, composition plasma and ener getic particle detectors and an ultraviolet ima ger/spectrometer. With Jupiter receiving 25 times less sunlight than the


EYEPIECE

October 2011

What's Up In The Sky
AAA Observer's Guide for October 2011 By Richard Rosenberg
October's Evening Planets. Jupiter dominates the sky. It is at opposition on the 28th at magnitude -2.9. With binoculars you can see Jupiter as a ball of light, not a point. But it is best through a telescope. Check out its alternating dark and light horizontal bands. Watch its four bright moons change position each night, sometimes their shadows onto Jupiter Coming into view this month is Venus, visible in the west. In early October it sets only a half hour after the Sun. As the month progr esses Venus slowly moves away from the Sun, setting one hour after and easily seen by the end of October. As a bonus, Mercury appears only 2° below Venus in the last week of October. See October 27 below. October's Evening Stars. The stars of the Summer Triangle still dominate the evening. Look low on the souther n horizon to see Sagittarius and Scorpius. On October 1st Antares lies closely below a crescent Moon! By 8PM Pegasus, autumn's signature constellation has risen in the east. Face its Great Square, four bright stars enclosing a nearly star-free region. Andromeda can be seen as a string of bright stars extending left from the square, leading in turn to Cassiopeia, Cepheus and Perseus, the major constellations of autumn. October's Morning Planets. Jupiter is up nearly all night. Rising around 1:30AM is the planet Mars. Make an effort to look at Mars on the mor ning of the first day of the month ­ it will be in the middle of the Beehive Cluster ! Mars slowly brightens this month from ma gnitude 1.3 to 1.1. Saturn was in conjunction with the Sun on the 13th, but quickly enter ed the morning sky (due to the favorable angle of the ecliptic). By the end of October it will rise 1Ѕ hours befor e the Sun. October's Morning Stars. The Orion group of constellations still holds our attention. Leo appears in the east shortly befor e sunrise.
2

October Day-by-Day
October 1 ­ This morning Mars is within the Beehive Cluster. Use binoculars. October 1 ­ Antares is 2° below a crescent Moon this evening. October 3 ­ First Quarter Moon at 11:15 PM. October 8 ­ Draconid meteor shower. Unfortunately the Moon is nearly full. October 11 ­ Full Moon occurs at 10:06 PM. October 12, 13 ­ The Moon passes Jupiter. October 13 ­ Saturn is in conjunction with the Sun, entering the mor ning sky. October 15 ­ The Moon passes the Pleia des and Hyades star clusters in Taurus. October 19 ­ Last Quarter Moon at 11:30 PM. October 21 ­ Orionid meteor shower peaks. October 26 ­ New Moon at 3:56 PM. October 27 ­ Find Venus low in the southwest. With telescope or binoculars look for Mercury 2° below Venus. If successful, look for a very thin crescent Moon 3° at five o'clock from Mercury. October 28 ­ Jupiter is at opposition. For more information on the Internet, go to www.aaa.org/month1109.

Analysis Says Prevailing Asteroid View May be Wrong
By Dr. Denton S. Ebel, Curator (Meteorites), AMNH
A new analysis of one of the most well-known meteorites on Earth provides strong evidence that the prevailing view of ma ny asteroids is wrong. Rather than randomly for med blobs of rock and dust stuck together, it appears the asteroid that was the source of the Allende meteor ite was large enough to have ha d a molten cor e, although its surface remained cold and solid. The new view also suggests astronomers' view of how planets like Earth for med ma y need r evision. The Allende meteor ite fell in Mexico in 1969, shattering into thousands of fragments as it slammed into Earth's
Asteroid continued on page 12


EYEPIECE

October 2011

A Message from AAA President Richard Rosenberg
Hello Members: A few weeks ago Ron McCullough and I travelled to Camp Simcha, wher e seriously ill childr en can enjoy the outdoors in a protected camp environment. We wer e lucky to have clear skies, which we showed off to the childr en. The campers wer e excited about astronomy and asked us question after question. It was a fulfilling personal experience to see young minds so involved in an observing session, despite their sever e medical problems. As I mentioned last month, I hope that the AAA can build a long ter m relationship with the ca mp. During the summer ther e are four groups of ca mpers; each group spends two weeks at the camp. This is a mutually beneficial situation ­ campers learn astronomy and the night sky and after they go to sleep we can view deep -sky objects in a dark sky envir onment. Stay tuned. Our annual Urban Starfest Central Park observing session will take place from dusk to 10PM on Saturday, October 22, at the Sheep Meadow. Rain date is the following evening. Don't miss this gather ing of large and small scopes. We urge our AAA members to join us in observing and also recommend bringing your scopes to share with others. The featured object will be Jupiter, only a week befor e it's at opposition. Please visit our web page on the event at http:// www.aaa.org/starfest. AAA member Laird Whitehill will teach our Fall class beginning Wednesday, November 2, 9, 16, 30, December 7, 14 (no class on Nov 23). Laird has a doctorate in astronomy from Cor nell University; his thesis advisor was Carl Sagan. The class will be six-weeks long and broken into thr ee parts as described below. Emphasis will be on evolution of our solar system over billennia. Location of the class will be deter mined shortly. Please see aa The Solar The Solar The Solar a.org for System P System P System P complete class descriptions. Laird's internal notes from which topics will be chosen: art I (up to Earth/Moon) art II (the inner solar system) art III (the rest of the solar system)

We hope to see ma ny of you at a AAA event soon. Sincer ely,

Rich Rosenberg, AAA President, president@aaa.org (718) 522-5014
Juno continued from page 1

probe Pioneer 10 and then Pioneer 11 using Jupiter as a gravitational assist to reach Saturn. But not until 1979 would Voyager 1 provide 19,000 pictures and Voyager 2 another 33,000 images, displaying the physical, geological, and atmospheric processes in the pla net, its satellites, ma gnetospher e and the discovery of active volcanism on the satellite Io which surprised scientists and astrophysics alike (for incr edible views of Jupiter in photos and video, visit http://www.boston.com/bigpicture/2008/07/ views_of_jupiter.html).

In 1992, the Ulysses spacecraft reached Jupiter en route to study our Sun. Ten years after Hubble's early pictures of Jupiter wer e transmitted to Earth, Cassini-Huygens' December 2000 trip to Saturn included the closest pass of Jupiter at 6.2 million miles away, the Galileo spacecraft enter ed the Jovian atmospher e in 2003 to avoid crashing into Europa and possibly contaminating that moon. NASA's New Horizons spacecraft, now half way to Pluto for a 2015 encounter, looked at Jupiter's atmospher e during a gravity assist boost in 2007. Our inter est in understanding this planet has continued to evolve. Now it is time to really get serious ­ Juno is on its way.
3


EYEPIECE

October 2011

Vesta Fiesta! Spacecraft Dawn Arrives at Vesta
By Jason Kendall
Dawn, the ion-propelled, strive-against-impossibleodds spacecraft has arrived at asteroid Vesta, 117 million miles from Earth, lodged snugly in the 344 million mile expanse between Mars and Jupiter. It is the first spacecraft to visit the second-largest body in our asteroid belt (Ceres, a future Dawn target is the largest). Dawn's mission is to orbit the 300-mile-wide asteroid to analyze and document its composition, properties and histor y. Vesta is the source of a significa nt fraction of all meteorites found on Earth. By remotely comparing the spectra of Vesta to that of discover ed meteorite sa mples Eucrite Camel Donga and Howardite Dar al Gani ( http:// w ww. s a ha r a met . c o m/ met e or it e/ ga ll er y/ H ED / index.html), NASA deter mined that ther e was a relationship to be explored. The driving force behind the Da wn mission was that these 4.5 billion year old meteor ites wer e all igneous rocks for med by processes not much differ ent than the magmatic processes of Earth. The impact event that liberated these meteorites from Vesta sent us proof of conditions that existed at the origin of our Solar System. A key mission goal will be to exa mine these conditions on Vesta and Cer es up close for the first time in our history as explorers. Dawn arrived on July 16th by the gentlest of engines, its ion-propulsion drive. Getting into orbit was not a matter of the traditional "Main Engine Burn." Instead, the spacecraft eased into orbit, much like two pla nes aligning to fly in tandem. But this is only the first stop. Dawn will orbit Vesta for one year, mapping its topography in multiple colors, gathering spectral signatures using a spectrometer capable of seeing and imaging in infrared and visible light, and exa mining the elemental composition with a gamma-ray and neutron spectrometer. The interior will also be probed with gravitational experiments hoping to deter mine how extensively this planetesima l differ entiated its interior. Still early in its mission, Dawn has already captured detailed ima ges of grooves running around the equator like shock waves in rock. The science tea m r emains baffled by the huge color variations and extreme albedo differences across the surface. Its South Pole is one giant crater that may reveal the exposed mantle of the asteroid.
4

On Earth, this would be the equiva lent of excavating the entire Pacific basin to a depth of 50 miles (visit http:// dawn.jpl.nasa.gov/ for a complete mission over view). In addition to the highly technical aspects of space exploration, there is also a personal side to the Dawn mission and the celebration of reaching Vesta. In my role as a NASA/JPL Solar System Ambassador I have participated in numer ous phone briefings and infor mation sessions with the Dawn science and Education a nd Public Outreach Team. After the conclusion of our training, Joe Wise, Manager of the E/PO Tea m, thought it would be fun to have a song contest to promote a nationwide "Vesta Fiesta." Seizing the opportunity, I offer ed to speak with my wife Donna, a composer and awardwinning songwr iter. They immediately agreed to the concept. Within two weeks Donna had written the lyrics and cr eated a basic jingle. Using a local producer, a professional recording and sheet music was prepared for review. The Dawn tea m responded favorably and asked that the song be presented at the event in Pasadena, offering to upload it as well onto NAS A's Dawn Mission webs it e ( hea r Donna's song: http :// www.DonnaStearns.com ). In support of Vesta Fiesta and NASA outreach I gave infor mational pr esentations at The New York City Public Library, The Inwood Hill Nature Center and NYSkies, a NY based astronomy resource and collaborative orga nization. At each event, Donna and recording partner Tony Imgrund perfor med her song live. But the best was yet to come. On August 6th we flew to LA to attend the live event in Pasadena. Upon arrival at the LA Convention Center, members of the Dawn outreach tea m gr eeted us, again praising Donna for writing her song. She was their star (no pun intended her e). The confer ence hosted 300 people and provided numer ous activities for childr en and adults featuring scale models of Da wn a nd its ion engines, interactive rides, ir on meteorites from Vesta and asteroid model ma king. At the end of the celebration's events, the science tea m presented its latest findings. The audience watched in
Vesta continued on page 9


EYEPIECE

October 2011

This Month's Book Review The Sun's Heartbeat...
By Edward J. Fox
"If the Sun is a star, why can't you see it at night?" High School Senior Bob Ber ma n answers this question and provides a wide variety of interesting and useful infor mation about our nearest star in his new book, "The Sun's Heartbeat and Other Stories from the Life of the Star That Powers Our Planet." (Little, Brown and Company, $25.99). "The best way to r espond to the low level of public space knowledge is not to recite figures and facts; it's to make the Sun real. To make people start afresh, like a newborn fawn looking up at that brillia nt fire for the first time," Ber man tells us. That is exactly what he does in a friendly conversationa l writing style, telling stories to engage his readers. With a liberal sprinkling of timely humor (at times quite corny) he consistently ma kes his tongue-in-cheek point. Ber man's book describes the ma ny ways the Sun affects Earth and our life ther eon. His stories are lessons in the history of the study of the Sun and of astronomy, filled with fa miliar historic na mes, intrigues and back-stories. Beginning at the time a ncient cultures around the world consider ed the Sun to be a god, the book recounts ma ny of the related fears and superstitions surrounding this stigma. By touching on the ma ny aspects of solar physics including stellar life cycles, sun spots, fusion, neutrinos, climate changes, ice ages, the aurora, and rainbows, and then adding the mystical effects of astrology, we gain a unique perspective of ancient cultures and how they reacted to astronomical phenomena. One of the most fascinating stories tells us how orbital geometry and mathematics was used to first verify Kepler's theory of the ratios of the various distances of the planets from the Sun. The distance of the Earth to the Sun was established as "the unit," one astronomical unit, or 1 AU. Once the concept of the AU was established, international competitions and cooperation used eclipses as a tool to establish the mea n distance of the Earth from the Sun ­ 92,955,807 miles.

Beyond explaining the technical aspects of a total eclipse and its uses in astronomical science, Ber ma n paints a minute-by-minute picture of the conditions experienced during an eclipse. He says it is something that no ca mera can capture, due to the subtleties of the lighting, and that it can impart a "life-changing" experience. The moon is 400 times smaller than the Sun, but also 400 times closer. This makes the two appear to be exactly the same size in the sky, ther eby allowing the moon to totally block out the Sun during a n eclipse. In explaining this phenomenon, Ber ma n tells us of the many expeditions launched to experience a total eclipse and the scientific studies that wer e carried out under those conditions. With the moon moving away from Earth at a rate of approximately 1-1/2 inches per year, in about 70,000 years it will not be possible to experience a total eclipse from the Earth. How lucky are we to experience the odd coincidence that makes a total eclipse possible at all? Current lifestyles and fear of the Sun are having a negative effect on us all. Mor e frequent time spent indoors and the "over-application" of sunscr een is contributing to "alarmingly" low levels of Vitamin D. This is a real conundrum of hea lth maintenance. Avoiding Sun to prevent skin cancer has created a population deficient in Vita min D, the most important anti-carcinogen. Ber man strongly supports lobbying the FDA to incr ease its currently recommended da ily dose of Vita min D to levels three or four times the current 400 Units standard. Ber man has written a very infor mative book in a light, friendly style. The stories are steeped in historical facts, but presented in a humorous ma nner. Read through the chapters and discover the book's true tone filled with chapters such as "Yon Fla ming Orb," "A Strange History of Seeing Spots," "Why Jack Loved Carbon," and "I'm an Aquarius, Trust Me." These titles spea k to his experience as a science writer reaching general audiences. For seventeen years Ber man honed his skills as an astronomy writer covering the "Night Watchman" column in Discover. He is currently a columnist and editor for Astronomy, a host for the Northeast Public Radio network a nd astronomy editor for The Old Farmer's Alma nac. From my perspective, this book was a pleasure to read, and since it was all about the Sun, quite "illuminating."

5


EYEPIECE

October 2011

Shuttle Atlantis Crew Lands at AMNH
By Maya Kushner
Excitement filled the room on August 16th as the young and young-at-heart watched the Atlantis shuttle crew enter Cullma n Hall at the AMNH. Launched on July 8th, STS-135 deliver ed equipment and supplies to the International Space Station (ISS) and returned safely to Earth after thirteen da ys in space. The flight represented a milestone in space exploration, capping an unpr ecedented 30 year shuttle program. Mission Specialist Sandy Magnus noted her perspective on NASA "We've got a lot of experience in low Earth orbit and we are ready to go beyond." Neil deGrasse Tyson introduced the crew, describing the importance of the shuttle program. This was a unique time for NASA when a reusable spacecraft could send a payload into orbit and bring it back, wher e "aeronautics met space exploration." This "space plane" had the capability of being a rocket at liftoff and an airplane when ma neuvering to land. Over 350 astronauts went into orbit, conducted cutting-edge r esearch, contributed to construction of the largest structure in space, and launched, recover ed and repair ed numer ous satellites and probes including most notably the Hubble Telescope. In the standing-room only crowd of Cullma n Hall filled mostly with children, we ask why a young child would be inter ested in an up close meeting with NAS A's last space shuttle cr ew. Perhaps some see themselves as having a future career at NASA. When a young girl na med Marion asked how much training one needed to go to space, Pilot Doug Hurley answer ed "All through college and flight school...you have to love to learn because you'r e going to constantly be training and learning new things." Mission Specia list Sandy Magnus responded that she ha d to learn medicine, photography, and the Russian language (see Sandy's interview at http:// www.youtube.com/watch?v=tQa_Wzu9GH4). Future astronauts dream of doing things in space that are not possible on Earth. Comma nder Chris Ferguson described his experience: "Being in space is your opportunity to be a fish. You can use ever y available cubic inch of space, not just floor space." Specialist Rex Walheim's favorite experience was being able to fly "Just like Su6

per man, from one corner of the shuttle to the other." He also recalls how cool it was during one of his last space walks to be able to gla nce down at his home town in California. When asked about eating, Pilot Hurley revealed that his favorite food was shrimp, but also explained that the NASA provided a wide variety of meals for astronauts. Since keeping the shuttle's weight down is important for liftoff, food is dehydrated for transport and r e-hydrated when eaten. Most foods are ready-to-eat military food (MRE's) or dehydrated food like the fr eeze -dried ice cr ea m sold at the Museum's gift shop. After the presentation, some of the younger childr en described why they liked the shuttle progra m. Richard, a seventh grader from Lake Geor ge Jr. -Sr. High School said he ca me to see the astronauts because it is the career he wa nts to have as an adult. Abigail, a ten year old fifth grader from School 10 in Linden, NJ said she was interested in science. Edward, a NYC eight and a ha lf year old ("I'm going into third grade") from The Parkside School wanted to meet the shuttle cr ew and has attended Space Camp at AMNH. Astronaut supporter Willia m from NYC, a first grader at the Dalton School "just wanted to be ther e to meet r eal astronauts." Even though these aspiring future astronauts may not understand the complexities of working in space, they understand that something special has occurred. They want to be a part of that magic. Mankind's potential to reach beyond Earth excites all of our ima ginations. Wher e does NAS A go from her e? Near ter m missions include the 2011 launch of the GRAIL mission (Gravity Recover y and Interior Laboratory) to deter mine the structure of the lunar interior from crust to core and the NPP mission (measuring Earth's atmospher ic and sea surface temperatures, humidity sounding, land and ocean biological activity, and cloud and aer osol properties). In November, the Mars Science Lab will launch a two year mission with rover Curiosity aboard to investiga te whether environmental conditions ther e favor microbial life and pr eserve evidence of life. Private enterprise Space Exploration Techno logies has partnered with NAS A for an unma nned November launch to dock its
Atlantis continued on page 9


EYEPIECE

October 2011

Briefs in Astronomy
By Dan Harrison
Asteroid Dust Clears Up Meteorite-Origin Mystery: The mystery of wher e most meteor ites come from has been solved by the first asteroid samples a spacecraft has returned to Earth. The unma nned Japanese probe Hayabusa returned a capsule containing over 1,500 grains of asteroid dust last year after its visit to 25143 Itokawa, a stony S-type and the most common kind of asteroid in the inner asteroid belt. Scientists long suspected that ordinary chondrites originated from such rocky asteroids, but as far as telescopes could tell, the chemistry of these meteorites and asteroids didn't match. This first close look at asteroid samples revea led how cosmic impa cts alter ed their surfaces. Rocky particles recover ed from the asteroid are identical to ordinary chondrites. NASA Lunar Launch: On September 10th NAS A launched twin robotic spacecraft to create the most precise lunar gravity map ever. The GRAIL mission will allow scientists to discern what's beneath the surface all the wa y to the cor e and also identify optima l landing sites for human or mechanical explor ers. Utilizing a lowpower ed rocket, the 2 million-mile trip will bring the probes to the Moon by the end of the year. They will orbit the poles, circling 34 miles above the surface. For nearly thr ee months, the craft will chase one another around the Moon, maintaining a distance of 40 - 140 miles between them. Scientists will measure variations in the gap, providing indications of shifting masses below or at the lunar surface--mountains in some places, enormous lava tubes and craters in others. When the mission ends in late spring, the craft will be within 10 miles of the surface before finally crashing into the Moon. Solar Storm Observation: For the first time, scientists have watched the evolution of a huge solar storm, from its origin until its collision with Earth. Utilizing one of two spacecraft orbiting the Sun for 3D mapping, StereoA watched the storm cloud shift and cha nge as it moved through space toward Earth at 3 million miles per hour. It scooped up solar-wind particles in its path, morphing into a tower ing wall of plasma by the time it neared us. Studying a coronal mass ejection (CME) should help

researchers better understand how solar storms evolve as they approach Earth. That, in turn, should impr ove space -weather forecasts. Scientists have seen CMEs erupt befor e, but they've generally only gotten hea d-on looks as they plow into Earth. New NASA Technologies Chosen: NASA has picked a deep space atomic clock, a giant solar-sail design and a laser-communications system as must-have technologies to help future space exploration. Launches are anticipated by 2015. The solar-sail demonstration mission will deploy a sail seven times larger than a ny ever flown in space, 125 by 125 feet. The atomic -clock project will fly and validate a miniature mercury-ion atomic clock 10 times mor e accurate than today's systems. The optical in -space communication system will send infor mation encoded in laser bea ms, letting spacecraft transmit data up to 100 times faster than befor e. Mars Phoenix Lander Update: The soil on Mars may be mor e capable of supporting life than pr eviously thought. Researchers have long suspected the surface is full of oxidizing compounds, making it difficult for complex molecules like organic chemicals to exist. But a new study analyzing data from Phoenix, suggests that instead, the surface is very similar to moderate soils on Earth. Dirt tested at its landing site was mildly basic, not over ly acidic. It also detected minerals that could serve as nutrients for life for ms, including magnesium, potassium and chloride. ESA Mars Express Satellite News: Evidence that a 40mile-wide crater was once a water-filled lake has been confir med by the ESA Mars Express satellite. The find was revealed in the discovery of a fan-shaped delta, wher e flowing water deposited dark sediments. The delta is in the Eberswalde crater in the souther n highla nds. The crater looks like a semi-circle indentation on the right side of the ima ge. Scientists think it was for med more than 3.7 billion years ago by a n asteroid impact. Only the right side of the crater is intact. The rest has been cover ed by the larger Holden crater, formed by a space rock that impacted that area at a later time. Enough of Ebserswalde was preserved so that the for ms of the 44 square-mile delta can still be seen. Near the top of the crater thin, jagged lines represent feeder channels that would have carried water and sediment.

7


EYEPIECE

October 2011

Mars Rover Opportunity Hints at Water: While studying its first rock on the rim of the huge Endeavour Crater NASA's Mars rover Opportunity has found another spot wher e warm water may have flowed or percolated long ago. The rock has high levels of zinc and bromine, elements often deposited by water, especia lly hot water. Endeavour's region looks completely differ ent than areas Mars Spirit and Opportunity have explored. Although warm water in other Martian systems was likely ver y acidic, rocks and soil around Endeavour might be mor e benign, as evidenced by cla y miner als observed by spacecraft orbiting Mars. Clay minerals do not for m in acidic conditions. Habitable Planets May be Rare: A Ger ma n-British tea m led by Professor Pavel Kroupa of the University of Bonn has suggested that long-ago collisions between clouds of gas and dust could explain why ma ny solar systems have pla nets with strange, highly tilted orbits, and why habitable worlds may be rare in the universe. Newly for ming solar systems may be jostled by interactions with nearby clumps of matter, leading to systems wher e planets ha ve dramatically tilted orbits and smaller, potentially habitable worlds are ejected. Most planets in our solar system have relatively circular orbits, line up along a plane close to the Sun's equator, and orbit in the same dir ection around the Sun as it spins. But many solar systems harbor planets that move in the opposite dir ection of their stars on highly tilted orbits. Using computer models, researchers showed protoplanetary disks can become considerably tilted if they encounter another nearby cloud of materia l and absorb some of its mass. These collisions ca n also r everse the disks' spin, lea ding to the odd orbits in many solar systems. Most planetary systems for m in clusters of stars wher e member stars are close together, so these encounters may be very common. Spotting Sunspots Early: Scientists have found a way to spot active regions of the Sun below the surface, a day or two before they erupt as sunspots. The method, which measur es acoustic wa ves, could spur more accurate ways to for ecast space weather and solar storms. Previously, sunspot regions could only be observed on the surface. Scientists exa mined sound waves and vibrations generated by movement of plasma inside the Sun. Specific regions wer e targeted, with surface refer ence points selected to measure the time it takes for sound waves to travel between the two locations from a depth of 37,300
8

miles. When acoustic waves crossed a sunspot, they propagated faster. After astronomers identified active areas, large emer ging sunspot regions beca me visible on the surface one da y later and smaller sunspot regions two days. Moon Redux: The Moon is either younger than thought or has evolved much differ ently over time, a new study suggests. Scientists estimate the Moon for med about 4.5 billion years ago in the aftermath of a collision between a Mars-size object and Earth. Many researchers have suggested the newborn moon's molten crust solidified after just tens of thousands to a few million years, but not everyone believes it cooled that rapidly. So scientists investigated Moon-rock sa mples. They discover ed the rocks apparently crystallized 4.36 billion years ago, well after the Moon is thought to have for med. This mea ns the Moon might be significantly younger than suspected, or the prevailing notion of a quickly cooling global ocean of magma might be wrong. Instead, per haps the crust for med over an extended period of time through crystallization of small pods of ma gma. "After many years of trying, we have found a way to reliably date the ages of lunar crustal rocks with high precision," said study lead author Lars Borg, a planetary scientist at the Lawr ence Liver more National Laboratory in California. "We can apply this technique to addr ess ma ny questions regarding the timing of ancient events on the moon. " Titan's Arrow: The mystery of a giant arrow-shaped cloud on Titan ma y be solved. It was likely caused by a massive wave rippling through the atmospher e. Cassini detected the cloud at Titan's equator in 2010. The cloud is huge, with each side running about 930 miles. To understand how such a cloud might have for med, scientists simulated the moon's atmospher e. They discovered waves at Titan's equator could or ganize clouds into this shape. These cloud patterns can result in downpours with up to 20 times average rainfall and ma y be key to shaping Titan's surface by erosion. Studying these patterns ma y provide insight into weather patterns on Earth. Kepler Finds The Dark Side: The darkest planet known in our galaxy has been discover ed. Kepler detected the Jupiter-size giant around a Sun-like star some 750 lightyears away towards Draco. The star reflects less than 1% of the sunlight falling on it. It apparently lacks reflective clouds, superheated as its atmospher e is to mor e than 1,800 degr ees by a star 3.1 million miles a way. But it's
Briefs continued on page 9


EYEPIECE

October 2011

so hot it emits a faint red glow. Light-absorbing chemicals such as vaporized sodium and potassium or gaseous titanium oxide could explain the planet's darkness. Diamond Planet Discovered: A newly discovered planet called a millisecond pulsar, five times the size of Earth and for med from a dead supernova has had its carbon crystallized into dia mond material. The star's system is located 4,000 light-years away in Serpens the Snake. Rotating over 10,000 times a minute with a dia meter of 12 miles, its mass is a 1.4 times that of our Sun. It transfor med from an average star to a radio pulsar when a dying star in its binary system exploded. When the second star reached the end of its life, it beca me a red giant and then a white dwarf. The pulsar absorbed mass from its companion, causing a faster spin. Astronomers think the core of the dwarf failed to mer ge with its compa nion. When they got close, the star lost much of its matter and moved out to a distance of a solar radius. Having lost mor e than 99.9% of its original mass and no longer engaged in fusion reactions, the dead cor e is classified as a planet. The star-turned-planet is 3,000 times larger than the pulsar it orbits in little mor e tha n two hours. The system would fit within the dia meter of our Sun. Black Hole Witnessed in Action: For the first time, a black hole has been caught tearing apart and swallowing a star that got too close. Scientists, who until now had witnessed only the after math of such events, say the observation is shedding light on relativistic jets, bursts of matter that shoot out at nearly the speed of light. In the past, scientists missed the fact that relativistic jets could for m as black holes ripped apart stars. New Star Questions Formation Theory: A primor dial star at the outer edges of the Milky Way may upset current theories of star formation. The star shouldn't exist. It lacks materials astronomers have long thought necessary for low-mass stars to for m and was for med after the supernova-explosion deaths of a few of the short-lived origina l stars. Using simulations and observations of other low-mass stars, astronomers have deter mined the minimum levels of various elements needed for a star's mass to pull together under gravity. But the composition of the primor dial star weighs falls significa ntly below those numbers. Current theor y dictates that carbon and oxygen are needed to cool material so gas can collapse into a star. The quantity of both elements is in sufficient in the new star. Befor e this find, astronomers thought

stars such as this would need to wait longer before for ming, waiting for more supernova star deaths to provide the materia ls needed.

Next Month in Eyepiece
Here's a peek at November for you all: Maya Kushner reviews AAA board member Tony Hoffma n's presentation at Custer Institute's 33rd Annual Astronomy Ja mboree; Alan Rude presents a fascinating article on ga mma ray bursts and a review of the Freema n Dyson lecture; Anne Kiefer covers the AMNH Frontiers in Astrophysics Lectur e Series "Knocking on Hea ven's Door" with Lisa Randall; Evan Schneider covers the latest on the Lunar Reconnaissance Orbiter presentation at AMNH with Carter Emmart and Apollo historian Andrew Chaikin; Jordan Kushner covers his obser ving session participation on the USS Intrepid; Ed Fox provides us with an insider's view on the NAS A Zer o Gravity experiments perfor med by his niece, Kerry Brennan and her teacher colleagues; Dan Harrison sends us his Briefs in Astronomy and more...

Atlantis continued from page 6

Dragon capsule with the ISS. NASA is working with Space X to assess its last two demonstration flights and approve docking the Dragon capsule at the International Space Station. Together, we look for ward to the new wonders these missions will revea l. Somewher e in the crowd today ma y be a future astronaut who will come back to AMNH to share his or her personal experience. If so, Eyepiece will be ther e as well.
Vesta continued from page 4

amazement as raw, unprocessed ima ges strea med live from Dawn itself, downloading through NASA's Deep Space Network. During the Q&A session the Dawn Mission Science Team applauded us again for creating and bringing the song to so ma ny people. They asked Donna, "Will you write a song for the Ceres Celebration in 2015 when Da wn arrives?" Judging by how happy she was that night and how soundly she slept on the plane coming home, I think the answer is an emphatic "Yes."
9


EYEPIECE

October 2011

Editorial: AAA ­ The Next Generation
By Evan Schneider
AAA members, can you feel the winds of change coming? It is subtle to most of you, but it is most definitely coming. Born out of years of progress ma de by a dedicated board of dir ectors and ma ny members who have selflessly volunteer ed their professional services, personal time, obser ving equipment, and perspectives on how to enr ich the AAA membership experience and to create outreach opportunities to the public, we can now see the Next Generation of our club clearly on the horizon. Two years ago, at a chance meeting with Neil deGrasse Tyson at a Swann Gallery space-memorabilia auction, I was directed to contact our dedicated president Richard Rosenberg to join AAA and follow my personal goal of learning mor e about astronomy. Since that introduction, I have been an enthusiastic AAA member, a writer for Eyepiece under the experienced guida nce of for mer editor Dan Harrison, beca me a new board member in June, and now repr esent AAA as the editor of Eyepiece as of this issue. I can only hope that, over time, mor e of you have the opportunity to work with fellow members as I have; to grow our club's presence, and to advance our collective knowledge of astronomy. During my short time as a AAA member I have witnessed the development of new ideas and concepts put into active discussion by our intrepid board of dir ectors focused on expa nding our membership and introducing new programming and broader opportunities for existing and prospective members to learn mor e about the science of astronomy, our club's core mission. Through the focused technical professiona lism of Marcelo Cabrera I have seen our website (www.aaa.org) develop into a sophisticated information center, our own electronic hub, reflecting all we do as a club and the ma ny benefits we offer to our members. Through the ongoing efforts of Jason Kendall, NASA/JPL Solar System Ambassador, I have watched his development of the Inwood Astronomy Project, bringing observing sessions and educational programs to children and adults in his community and throughout New Yor k City. With the guidance of the AAA board, club finances have been carefully managed by financial secr etary Joe Delfausse and treasurer Tom
10

Haeberle. Daily interactions of board members through our Google Groups communications network r esona te ever y day with new ideas. All of these efforts are made to support our loyal membership, mor e tha n 400 strong and growing steadily. The purpose of this article is not to highlight specific programs or commitments. It represents a pivotal marker in time. It is a reminder to each of us that behind the scenes, countless hours are being spent on your behalf to create innovative ways to experience astronomy. Our growing relationship with the Hayden Pla netarium will present new opportunities to host joint events benefiting our club and AMNH members alike. Planned outreach to other astronomical and scientific organizations will give us new paths to explore and access to others like us who are excited about field work being perfor med by astrophysicists, other scientists and fellow amateur astronomers. Ther e are a significa nt number of events being planned for the upcoming year (watch for updates in future issues of Eyepiece), and you can all be a part of this exciting time in our development. We urge you to visit our website weekly, to read Eyepiece monthly (even write for it if this is your passion) and to join us at observing sessions, lectur es and classes that are available for our members throughout the year. Wher ever you can, get involved. Ask your friends to join you and become AAA members. Email us to participa te in AAA sponsored events. Live your membership as amateur astronomers. It's all ther e in front of you to experience every day. We are diverse and our you are all fortunate to be a part of a dyna mic group of members with common inter ests in astronomy universe. Take a moment to look in the mirror part of AAA - the Next Generation.

Astronomical Facts of the Month
The universe 1,070 mph; the orbits the Sun around the cent is in constant motion. Our Earth rotates at Moon orbits the Earth at 2,288 mph; the Earth at 66,614 mph; and our solar system rotates er of the Milky Wa y at 514,496 mph.


EYEPIECE

October 2011

Events on the Horizon October 2011
M: me mbers; P: open to the public; T: bring your telescopes, binoculars, etc.; C: cancelled if cloudy; AMNH: For ticket information, call (212) 769 -5200 HQ: at AAA headquarters, Downtown Community Center, 120 Warren St. For directions to AAA observing events, check the club's website, www.aaa.org.
Saturday, October 1 (rain date Oct 2), 7:30-11 PM P, T, C Observing at Gateway National Park, Rockaway, Q ueens Next date: November 19. Monday, October 3, 7:30 PM, P, AMNH -- Frontiers in Astrophysics Lecture Series Strange New Worlds with Ray Jayawardhana Hayden Planetarium Space Theater, Enter at 81st Street Next date: November 14 Tuesdays October 4, 11, 18, 25, dusk-10 PM P, T, C Observing on the High Line, Manhattan Enter at 14th Street. Next dates: April 2012. Wednesday, October 5, 8-10 PM , P, T, C Observing at Brooklyn Heights Promenade At end of Montague Street. Last session of 2011. Thursdays October 6, 13, 20, 27, sunset-10 PM, P, T, C Observing and movie, Pier 1, Brooklyn Contact Rich Rosenberg at president@aaa.org or 718-5225014 to check whether observing is on. Info: www.aaa.org/movieswithaview. -- Last sessions of 2011. Friday, October 7, 8:30-11 PM, P, T, C Observing at Floyd Bennett Field, Brooklyn Next date: November 4. Fridays October 7 and 21, Monday October 31, 8-11 PM, P, T, C Observing at Inwood Hill Park, Manhattan Next dates: November 11, 18. Friday, October 14, 8:30-11 PM, P, T, C Observing at Carl Schurz Park, Manhattan Wednesday, October 19, dusk-11 PM, P, T, C Observing at Prospect Park, Brooklyn Friday, October 21, AAA John Marshall Lecture, 6:15 ­ 8 PM, FREE, P Freeman Dyson of the Institute for Advanced Study will speak on Other Ways of Looking for Life in the Sky Next date: November 16. Saturday, October 22 (rain date Oct 23), dusk to 10 PM, P, T, C Urban Starfest, Sheep Meadow, Central Park See president's letter page 3. Saturday, October 22 (rain date Oct 29), dusk to when you want to leave, M, T, C Observing at North-South Lake in the Catskills. Next date: Last session of 2011. Saturday, October 29, 7:30-11 PM, P, T, C Observing at Great Kills Gateway National Park, SI Next date: November 19. Saturday, October 29, 10 AM-noon, P, T, C Solar observing in Central Park. At the Conservatory Water. Next date: November 19.

Highlight: Freeman Dyson Lecture
Dr. Freema n J. Dyson, one of the nation's most renowned physicists and professor emer itus at the Institute for Advanced Study in Princeton, N. J., will open the AAA's 2011-12 lectur e series Frida y, October 21 when he speaks on "Other Ways of Looking for Life in the Sky." The free public lectur e begins at 6:15 p. m. in the Kaufma nn Theater of the AMNH.
11


EYEPIECE
Asteroids continued from page 2

October 2011

atmospher e and strewing them across dozens of miles of desert. When the solar system for med, pla nets built up through accretion of smaller objects colliding and sticking together. When these collections reached a certain size, radioactive elements within them heated up enough so the rock melted, and heavier elements sank toward their cor es. This separating process, known as differ entiation, ended up producing concentric layers of differ ent composition. In the metallic cores of these bodies, swirling eddies of molten metal produced a magnetic field. Scientists ha ve long thought asteroids that for med cores must have completely differ entiated and melted thr oughout their interiors. New findings suggest that may not be the case. Many asteroids with cor es might be partially differ entiated, with their outer regions largely unmelted. The shift in thinking comes from lab work and theor etical modeling. Lab studies found evidence for magnetization built up over millions of years, in a piece of the Allende meteorite. A separate study showed how ma gnetization could ha ve occurred, and why that changes not just our view of asteroids, but also of how all the planets for med and wher e Earth's oceans ca me from. Amateur Astronomers Association PO Box 150253 Brooklyn, NY 11215. ADDRESS SERVICE REQUESTED

The Allende meteorite was a carbonaceous chondrite. "Chondrites are conglomerates of tiny rocky pieces stuck together, and individual components such as chondrules for med by poorly understood processes in the primordial solar nebular disk," says the AMNH's Denton Ebel, an AAA member, who participated in the study. "They're not interstellar materia l." The new analysis shows that while newly for med asteroids melted from the inside out because of their radioactive elements, their surfaces, exposed to space and continuing to accumulate layers of cold fragments, remained cold. Computer modeling shows this disparity of a molten interior and cold, unmelted crust. Decisive evidence ca me from studies on how miner al grains within the meteorite magnetize. The magnetic orientations of all the grains line up, showing they beca me ma gnetized after all material had stuck together rather than being a remna nt of earlier magnetic fields in the swirling cloud of dust from which the object formed. In addition, using a form of radiometric dating, scientists could deter mine the ma gnetization took place over millions of years. That rules out a theory that the grains could have become ma gnetized as a result of a brief pulse of ma gnetism in the cloud of dust.

First Class
12