Volume XXI No. 1 September 2009 What's Inside… New Members Pg 2 Book Reviews Pg 3 Stewart's Skybox Pg 5 General Meeting Pg 8 Sidewalk Astro Pg 9 Hank & Mary Adams Pg 10 Contacts Pg 11 Theater in the Sky Pg 12 Note: Use bookmark panel in Adobe Reader. President's Letter By Gordon Bond The room was finally quiet as the group of noisy, indifferent children moved on. In welcomed silence and solitude, I regarded the relic in the tall glass case with a degree of reverence. To some, it probably seemed like just a stick. To me, there was a visceral thrill being in the presence of where it all began. This was Galileo Galilei's telescope. The display at the Franklin Institute in Philadelphia had marked the first time this telescope had been beyond the borders of Italy. The exhibit as a whole left something to be desired-the instruments, all resulting from the Medici family's patronage, were magnificent, but the contextual information describing them could have been better. Nevertheless, there it was-a telescope made and used by Galileo himself, a man celebrated and mythologized in the pantheon of science. It wasn't that this crude scope, cutting edge technology at the time, was the first. What made it special was the simple, in retrospect, even intuitive, thing he did with it. He looked up. That moment at the museum, as I lingered between groups of visitors, I savored the history and how we are all heirs to the universe this simple tube revealed. As you know, my wife, Stephanie, and I have been avid stu-dents of history for a long time. We join in as the world marks Galileo's 400-year milestone. At the same time, we, here at AAI, are about to observe a significant marker of our own. I am proud to be able to write this traditional letter as AAI's President during our 60th Anniversary year. Such milestones naturally give us reason to pause and remember how far we've come and contemplate where we may be going. It is humbling to consider the notable names who have served as President before me, and it reminds me how we are all part of a greater heritage of service, educa-tion and fellowship. I hope all of you will join in the celebration of our achievements at our 60th Anniversary Dinner on No-vember 15, 2009. There is still time to reserve your seat. For more information, please visit our website, www.asterism.org and click on "Special Events." The downside of being President, however, is the sad duty of representing AAI when a member passes away. We lost two dear members recently, Hank and Mary Adams. Hank, who died in July, served as AAI's President, Research Committee Chair, Trustee, and Nominating Committee Chair. Even when he held no office, he would still sit in on our Executive Committee meetings. It was Hank who helped pioneer AAI's use of the CCD camera. Indeed, his intellectual curiosity was strong throughout his life and he was always at home even with the newest technology. Mary, who died in May, could almost always be found behind the Sales Desk at Sperry, helping with refreshments or wherever a hand was needed. Together they formed a loving and devoted couple whose depth of affection and compan-ionship were evident to anyone who saw them. Tributes to them both may be found on our web-site, www.asterism.org, by clicking on the "AAI People" link along the left side of the homepage. AAI continues its tradition of education and public outreach. I am grateful to our Officers, Committee Chairs and members-at-large who volunteer their time and talents. You are the life blood of this organization. I am pleased to be able to announce a successful launch of two new initiatives. AAI's Sidewalk Astronomy Program Committee, chaired by Helder Jacinto, consists of both newcomers and old hands. Thanks to their efforts, AAI looks forward to bringing an appreciation of the night sky out of the observatory and into the community. In addition to our existing public outreach programs, we hope to increase community awareness of AAI and encourage new memberships. We are very fortunate to have Dr. Dale Gary from the New Jersey Institute of Technology (NJIT) as the Chair of our new Academic Outreach Program. The goal of this program will be to foster a greater coopera-tion with colleges and universities in the New Jersey area. We have many resources -- knowledgeable peo-ple, various kinds of equipment, and two observatory sites - which can be made available to researchers. Such relationships will, in turn, help with research done by our existing members, attract new members, and provide a resource for future speakers. My sincere thanks to my Vice President, Steve Clark, for juggling work and family responsibilities with scheduling a fine slate of speakers for our 2009-2010 General Meeting season. We are still collecting presen-tation summaries and bios for the brochure. I will an-nounce our September speaker via a separate email, and the full schedule will be available shortly. I look forward to working with Union County Col-lege to further our shared missions of education and community service. Most of all, I would like to thank all our members for their continued support of Amateur Astronomers, Inc. as we enter the next sixty years! ON THE PLUTO CONTROVERSY: Two Books, Pro versus Con David A. Weintraub, Is Pluto a Planet?: A Historical Journey through the Solar System, Princeton University Press, 2007, 241 pages. Neil Degrasse Tyson, The Pluto Files: The Rise and Fall of America's Favorite Planet, 2009, 184 pages. The AAI Library has added two books on opposite sides of the current burning controversy over whether Pluto should be considered a planet. On the "pro-Pluto" side is "Is Pluto a Planet?: A Historical Journey through the Solar System. On the "anti-Pluto" side is "The Pluto Files: The Rise and Fall of America's Fa- vorite Planet". Weintraub traces the discovery of the Solar System and what constitutes a planet from the Greek phi-losophers to the present day. Under geocentrism, we know that Earth was a not considered to be a planet but the Sun, Moon, and other known bodies were. Of course, after Copernicus and Galileo, under heliocen-trism, Earth became a planet, the Moon was not a planet, and the Sun was the primary body of the Solar System. Kepler, Newton, and Halley put heliocentrism on firm scientific footing. It was also established that what could not be a planet, that is, comets, could still be Solar System objects. The problem of what could be considered a planet and then not be considered as such came with the discovery of Ceres and other asteroids. It appeared (Continued next page) Book reviews (continued from previous page) that Bode's Law was a scientific fact. But when the other smaller bodies were found, Ceres was no longer considered a planet. The discovery of Uranus and Neptune finally brought up questions considered by Percival Lowell and others of what we should call Pluto. In 1908, based on calculations of the orbit of Uranus, E.C. Pickering proposed what he called Planet O. Later came hypothetical planets lettered P through U (but no V or W) which weren't necessarily trans- Neptunian. For the last eight years of this life, Lowell fruitlessly searched for what he called Planet X. None of these bore any resemblance to Pluto. But, what constitutes a planet? Weintraub has three criteria. First, a planet must be of such a size that at no time in its life could it produce energy by nuclear fusion. This omits brown dwarfs. Second, a planet must be round. This excludes all but the largest asteroids but includes Ceres and some other bodies including the larger Kuiper belt objects (KBOs). The round shape of celestial bodies depends on several factors including their material composition, therefore, size or mass is not the sole criterion. Third, a planet must orbit a star. This excludes free-floating objects ejected from some other solar sys-tems as well as the bodies orbiting pulsars. So far as Weintraub is concerned, what constitutes a planet must solely be governed by scientific and not socio-logical or historical criteria. He regards the designa-tion of major and minor planets as flawed. Essentially, a planet is a planet, period. For any confused educa-tors, Weintraub believes that young children can readily understand the wonders and nuances of the Universe. He believes that children's astronomy edu-cation should be based on more profound principles than mnemonics like "My Very Educated Mother Just Served Us Nasty Pizzas". Less can be said about Neil Degrasse Tyson's book. To Tyson, what constitutes a planet is basically historical and sociological. Actually, the book is really more self-promotional as it is anything else. When the public began attending the Rose Center at the Ameri-can Museum of Natural History, it was noticed that Pluto wasn't in the Solar System exhibit, and that caused some consternation. Tyson vindicates himself in the book. Only one chapter deals with Pluto on a scientific basis. The rest deals mostly with public notions and the debate around Pluto. Tyson makes no secret about which side he is on. This book tends somewhat more to the "My Very Educated Mother Just Served Us Nasty Pizzas" level than it is anything else. To sum up: Weintraub's book represents solid as-tronomy. He makes a thesis and backs it up with facts and research. Both are readable but Weintraub's book is a more satisfying intellectual experience. OTHER BOOKS ON THE SAME TOPIC The AAI Library has "Pluto and Planet X" by Wil- liam Graves Hoyt which is about the early search for Pluto at Flagstaff Observatory. We also have "Out of the Darkness" by Pluto discoverer, Clyde Tom- baugh, and Charon discoverer, James Christy. Our collection also includes "Pluto and Charon" by Alan Stern and Jacqueline Mitton. Finally, the club library has David H. Levy's "Tombaugh: A Biography". A LIBRARY FOR ALL MEMBERS Most books may be borrowed at no cost for up to eight weeks. A maximum of four books may be kept out by a borrower at any one time. Periodicals do not circulate. Certain other books, including reference books, certain "coffee table" volumes that are large and expensive containing mostly photography, and archived historical books do not circulate. The AAI library is a benefit for all members of our club. See you at Sperry! Stewart's Skybox by Stewart Meyers This year is turning out to be a big year for the Moon. July 20th marked the 40th anniversary of the landing of Apollo 11, the first human being landing on a body outside Earth. This month marks the 10th an-niversary (September 13th) of the biggest lunar explo-sion that never happened, except in the imagination of Gerry Anderson and was the premise for his 1970's science fiction TV series "Space: 1999".Despite the reputation that series acquired, the basic premise was taken and inverted for, not one, but two recent TV productions - the ABC Family ca-ble series "Three Moons Over Milford" (an impact destroys the Moon and sends the wreckage on a col-lision course with Earth) and the ABC miniseries "Im-pact" (which not only had an impact knock the Moon into an Earth collision course but had the heroes use a massive nuclear explosion to restore the Moon's orbit).But, 2009 also marks the 400th anniversary of the first telescopic observation of the Moon by Galileo and is being commemorated by the International Year of Astronomy (IYA). In addition to all the anniversaries, real and fic-tional, the Moon is also drawing renewed interest from space scientists around the world as a number of probes from different nations have been sent to the Moon recently, including the Lunar CRater Observa-tion and Sensing Satellite (LCROSS) mission which will be discussed in detail in the October column. So, all this talk of lunar anniversaries and explosions means that this month's column will focus on those lunar features that Galileo first noticed on the Moon: the craters. A Cratered Past Up until 1609, most people believed the Moon to be made of the same kind of perfect substance that all celestial objects were and that its surface was free from defects. Of course, the large light and dark ar-eas of the lunar surface were visible to the unaided eye. But these were explained away, first by invoking mythology (i.e. "The Man in the Moon"), then the Aris-totelian cosmology and medieval Christian dogma which claimed that the dark markings were the result of the Moon being close to the corrupting influence of Earthly matter. A few had other ideas, such as Leo-nardo da Vinci who wrote that the dark areas were land and the bright areas were oceans. Then Galileo pointed his new telescope at the first target most people point a new telescope towards - the Moon. Even though the quality of the image was poor and fuzzy by modern standards, he noticed that there were large circular depressions with rims that looked like mountains. This is the first description of lunar craters. Unfortunately for Galileo, this and the other discoveries he made through his instruments got him into considerable trouble with the Catholic Church. Even when most people accepted the idea of a cratered lunar surface, there was remarkably little speculation on why they were there. Since the only craters people knew about on Earth at the time were volcanoes, many astronomers assumed the lunar craters were simply volcanoes and left it at that. But some had different opinions. About the earliest non-volcanic speculation came from Robert Hooke, Sir Isaac Newton's archenemy at the Royal Society, who in 1667, proposed that the lunar surface was in a boiling molten state in the distant past and that the craters are the solidified remains of burst bubbles. While this initially seemed logical, the sheer scale of the craters made the idea appear implausible. (continued next page) Stewart's Skybox (continued from previous page) In the 19th century, a rather odd theory emerged which maintained that the Moon was once covered completely by an ocean. And, like Earth's ocean, it had organisms similar to coral. Like their Earth coun-terparts, the putative lunar coral created large atolls, which became the craters we see today after the an- cient ocean was gone. This theory was never taken seriously by anyone except the man who proposed it. Lest we think that odd ideas about lunar craters were only things of the distant past, one of the truly strange theories emerged a little over a century ago. In 1894, German amateur astronomer Hans Horbiger put forth a theory that, among other things, claimed the Moon was made of ice. Occasionally, according to this theory, parts of the surface ice would melt and form pools of water, which would quickly evaporate, leaving a round depression or crater. Horbiger's the-ory was considered ridiculous from the outset and was soon discarded. However, it experienced a re-vival in Germany over thirty years later and, as a re-sult of an endorsement from Heinrich Himmler and a rather unenthusiastic one from Hitler, the Ice Moon theory became officially approved by the Nazi party. The end of World War II put a permanent end to that theory. Trying to Make an Impact With no serious rivals, the volcanic theory of the origin of lunar craters was the prevailing view for most of the era of telescopic lunar observations. However, some problems eventually emerged. For example, the shapes of most lunar craters are not very consis-tent with volcanic craters. This was explained away by claiming that the conditions on the Moon (low gravity and no atmosphere) allowed for volcanism to behave differently. And, since nobody had any viable alternatives, that explanation served. But during the 19th century, a new possibility emerged - cosmic im-pact. Probably the first mention of lunar impact craters was in 1822, when Franz Gruithusen (who would also claim that the "ashen light" on Venus was the result of massive bonfire celebrations on the surface) pro-posed that the craters formed when large meteorites struck the Moon before the lunar surface completely solidified. In 1873, British astronomer Richard Proctor had a similar opinion. Further support for crater forming impacts came shortly after World War I when Daniel Barringer no-ticed that bits of meteoritic iron were found near a crater in Arizona that geologists had claimed was the result of a volcanic steam explosion. Barringer felt that the iron and the crater were connected and that a large nickel-iron meteorite had struck the Earth at that spot. He also believed that the impactor was still bur-ied under the crater and that it might be mined com-mercially. By the late 1920's, after years of efforts to drill down to where the impactor should be, Barringer was forced to conclude that it exploded on impact and that the scattered iron around the crater was all that was left. While a commercial failure, Barringer's work pretty much proved that at least one crater was formed by an impact. The first person to come up with a detailed version of the impact model was American astronomer Ralph Baldwin in 1949.He explained that, during a cosmic impact, the impactor would hit the Moon with enough kinetic energy that it would penetrate a bit into the lunar surface, coming to a complete stop. The im-mense kinetic energy of the impactor's velocity would instantly be converted into heat and create an explo-sion, hurling out large amounts of surface material and excavating a crater. As further proof, he also pointed out that the depth to diameter ratios of lunar craters were identical to those of craters created by large artillery shells and conventional bombs. While Baldwin provided a detailed mechanism which gave some support to the impact model, the volcanic the-ory was still fairly popular. A Shoemaker Solution Eugene Shoemaker started his scientific career in 1948 by working for the U.S. Geological Survey (USGS).His first job was to aid in searching for ura-nium deposits. This work had Shoemaker exploring extinct volcanic features in the western United States. Witnessing these craters got Shoemaker thinking about the ones on the Moon and how they did not resemble the volcanic craters that he was studying. (continued next page) Stewart's Skybox (continued from previous page) In 1952, Shoemaker visited Meteor Crater in Ari-zona. Seeing this impact feature convinced him that the lunar craters were indeed of impact origin and worthy of more detailed examination. By 1956, Shoemaker suggested the idea to create a geological map of the Moon to his bosses at the USGS. How-ever, the Moon was not high on their list of priorities, but the Cold War and its arms race was. Shoemaker was assigned to study the effects of the underground nuclear tests in Yucca Flats, Nevada. Upon seeing the craters left by the nuclear tests, he noticed that they did possess the same depth to diameter ratio as lunar craters. Shoemaker returned to the study of impact craters in 1957.And it was in this study that he found a defi-nite sign that could identify craters formed by cosmic impact. Shoemaker, along with Edward Chao, dis-covered coesite at Meteor Crater. Coesite is a form of quartz that had its crystalline structure damaged by exposure to extremely high pressure. The mineral is found only in and around craters formed by cosmic impacts and nuclear explosions. Thus, the impact origin of Meteor Crater was proven beyond doubt, and the impact origin model of lunar craters was given a major boost. When it was decided to send astronauts to the Moon, Shoemaker applied for the Apollo program. Unfortunately, he suffered from Addison's disease, and he was cut from the program in 1963.Shoemaker then turned to training astronauts in geology with em-phasis on what to look for when they got to the Moon. In 1965, he was placed in charge of the USGS Center of Astrogeology in Flagstaff, Arizona. This was not the end of Shoemaker's interest in cosmic impact which he maintained even after his retirement from the USGS in 1993 and until his death in 1997.As a fitting tribute to this great man, his ashes were placed onboard the Lunar Prospector probe. So, Shoemaker got the lunar trip he wanted, even though it was after his death. A few holdouts continued to support the volcanic model, at least in some form. The most noteworthy of these was Sir Patrick Moore, who, even as late as 1976, still believed lunar volcanism played a major role in crater formation. Today, it is thought that there was some minor volcanism on the Moon in the distant past. The signs for this are lunar domes (mainly the ones with pit-like features at the top), some dark smudges of volcanic ash seen near a few craters, and the bits of orange volcanic glass returned by Apollo 17. Crater Categories Now that the story of how lunar craters are formed is out of the way, it is time to consider the kinds of craters one sees on the Moon. Over the years of tele-scopic observation of the Moon, several schemes for classifying craters have been adopted. In 1978, Charles Wood (who currently writes the "Exploring the Moon" column in Sky & Telescope magazine) and Leif Andersson of the Lunar & Planetary Lab came up with "LPC Crater Types", a simple system that covers about 99% of all the craters on the Moon. The LPC Crater Types system is as follows: This does not mean that larger features were not derived by impact. The LPC system considers lunar features larger than few hundred kilometers in diame-ter as basins. But these, as well as the lunar mare, are also the result of impacts. The main difference is the size of the impacting object. The lunar mare (the large dark areas we see on the Moon) formed fairly early in lunar history, during a period known as the Late Heavy or Great Bombard-ment Period about 3.9 billion years ago. Asteroids about the size of the one that hit the Moon in "Impact" struck the Moon, gouged out enormous craters and cracked the lunar crust. Lava from the still-molten interior of the Moon then came up through the cracks (Continued on page 8) GENERAL MEMBERSHIP MEETING SEPTEMBER 18, 2009 "Studying the Formation of Galaxies Using Hydrogen, Big Mirrors, and Digital Cameras" Using the modern generation of huge telescopes, astronomers have discovered incredibly distant young galaxies that represent the precursors of our familiar local galaxy types. They are so far away that their light has spent most of the lifetime of the universe traveling towards Earth. Dr. Gawiser will describe the process used to study these galaxies as part of the MUSYC survey. He will present the recent discovery that small blue galaxies will evolve into present- day galaxies like the Milky Way. These meeting are open to the general public and I would encourage all our members to attend and bring their family and friends! 8 p.m. in the Main Lecture Hall Stewart's Skybox (continued from page 7) in the crust and filled the ancient basins burying ear-lier craters (traces of some can be seen today) and damaging other old craters. In one strange case, lava filled the crater Wargentin all the way to the top of the rim, creating the only known plateau on the Moon. But, the honor for the largest impact feature on the Moon (and solar system as well) has to go the South Pole-Aitken basin. This crater wasn't discovered until the 1960s when it was seen and measured from spacecraft because it is mainly on the far side. This feature near the lunar South Pole is 2500 kilometers in diameter and 13 kilometers deep. Some scientists think the impact that formed this feature might even have brought up material from the lunar mantle and, therefore, it is worth further study. Some craters on the Moon have bright linear fea-tures known as "rays" radiating from them. They are not cracks as once believed, but are lines of ejected material that is of lighter color than the surface. Over time, exposure to sunlight, micrometeorites, and cosmic radiation darken the material so that it matches the surface. Rays are seen only around rela-tively young craters. Floors of Darkness There are craters all over the Moon, even at the lunar poles. But these polar craters are special. Be-cause of the low axial tilt of the Moon, the Sun gets only a few degrees above the lunar horizon at the poles, and it cannot shine into some of the craters there. This makes their floors some of the coldest spots in the inner solar system. These shadowed craters are also of great interest to those planning future manned missions to the Moon. It is inside of one of these permanently shadowed craters that NASA will make a crater of its own next month with the LCROSS mission, the topic of next month's col- umn. Stay tuned. AAI Launches Sidewalk Astronomy Program AAI's Sidewalk Astronomy program aims to bring astronomy -- and our club -- more directly to the community. Our volunteers simply set up a telescope on the street (or anywhere people gather on a clear evening) and give the passers by an opportunity to see celestial objects firsthand, free of charge. We also hand them a flier telling about AAI, and we invite them to come visit Sperry Observatory for views through our telescopes and for our "Fridays At Sperry" presentations. This sidewalk program augments the public outreach we've already been doing at indoor venues like schools and libraries and with youth groups at Sperry. Helder Jacinto is coordinating the schedule for these sidewalk events. If you would like specific info about times, dates, and locations, please contact him at jacinto.hf@gmail.com. You might also consider participat-ing in one or more of these outings. You don't need a telescope to do so. We can always use an AAI rep-resentative to help distribute written information and to answer questions about our club. Meet your neighbors and talk about astronomy. What could be more fun? Henry George Adams died on Tuesday July 21, 2009 at the Inglemoor Care Center in Livingston, New Jersey. He was 84. Born and raised in New York, a graduate of Stuyvesant High School, he served his country proudly in the U.S. Army in World War II. He was captured in Germany late in the war, and almost starved to death before being rescued. Undaunted by this experience, he returned home and re- ceived his electrical engineering degree from City College of New York in 1956. Hank, as he was known to many of his friends, was an accomplished engineer whose services and knowledge were in high demand. He retired as the primary engineer at the Automatic Data Processing Corporation (ADP). Throughout his life, Hank built up many friendships through his memberships at the Raritan Yacht Club, at the Plainfield Ski Club, and, for the past 24 years, at his astronomy club, Amateur Astronomers, Inc. (AAI) in Cranford, New Jersey. Hank was one of the early adaptors of Charged Coupled Device imaging among amateur astronomers. Hank perfected his astrophotography techniques in his private observatory which he constructed at his home in West Orange, NJ. He also brought this knowledge to AAI where he led many seminars, and gave numerous presentations on imaging and other astronomical topics. Hank was one of the first amateur astronomers to have imaged the extremely faint dwarf planet UB313 which is now known as Eris. At various times, Hank was chairman of the Research Committee, a trustee of the corporation, and president of AAI. Mr. Adams was predeceased by his wife of 45 years, Mary Hardiman Adams, who passed away in May of this year. Surviving are his brother, William, and William's wife, Yvonne, of Cambridge, New York and their two children, Pamela and Robert. Visitation was on Thursday, July 23, 2009 from 2-4 and 7-9 p.m. at the Costello-Greiner Funeral Home, 44 Green Street, Woodbridge, NJ 07095. Funeral services were held on Friday at 10:30 a.m. at the funeral home. Please visit the AAI People page on the AAI website at www.asterism.org to see eulogies and remembrances by Gordon Bond, Karl Hricko, and Mike Luciuk. EMAIL CONTACTS presi-dent@asterism.org President of AAI editor@asterism.org Editor of The Aster-ism Ray Shapp, Editor Deadline for submis-sions to each month's newsletter is the first Friday of that month. member-ship@asterism.org AAI Membership Chair trus-tees@asterism.org All three Trustees of AAI ray@asterism.org Ray Shapp for the website exec@asterism.org Executive Committee plus Trustees QOs@asterism.org All Qualified Observ-ers info@asterism.org AAI president, corre-sponding secretary, and computer ser- vices chair re-search@asterism.org Research Committee techni-cal@asterism.org Technical Committee MEMBERSHIP DUES Regular Membership: $21 Sustaining Member-ship: $31 Sponsoring Member-ship: $46 Family Membership: $5 First Time Ap-plication Fee: $3 Sky & Telescope: $32.95 Astronomy subscription: $34 (Subscription renewals to S&T can be done directly. See "Membrship-Dues" on website for details.) AAI Dues can be paid in person to Membership Chair or Treasurer, or by mail to: AAI, PO Box 111, Garwood, NJ 07027-0111 DOME DUTY September 18 Team B September 25 Team C October 2 Team D October 9 Team E October 16 Team A FRIDAYS AT SPERRY September 25, 2009 "Space News / Ask Dr. Lew" Karl Hunting / Dr. Lew Thomas October 2, 2009 "What's Up? A Down to Earth Sky Guide" Kathy Vaccari October 9, 2009 TBA All schedules above were accurate at time of publication. Please check www.asterism.org for latest information (click on "Club Activities") DR. LEW'S SEMINARS See Dr. Lew Thomas for possible upcoming seminar topics. (Choice of topic at Dr. Lew's seminars is determined by partici-pants' interest) October 2009 features two of the closest planet-to-planet conjunctions of the entire year. During the first half of the month, Saturn pulls away from the rising Sun to first meet Mercury and then Venus, passing about half a degree from each inner planet. Don't let the morning schedule deter you. There are three reasons why October is the best month of the year for observing a.m. events. First, Daylight Saving Time delays sunrise until around 7 a.m. or later, so at 6 a.m. the sky is still dark. Second, the ecliptic, the plane of the Earth's orbit, is nearly vertical to the eastern horizon in October, so the outer planets jump up into the sky after passing behind the Sun, while the elongations of the inner planets from the Sun translate well into altitude. Third, the first full month of fall usually provides plenty of crisp, clear mornings for observing. Best of all, this month, brilliant Venus is on top of everything, providing unmistakable guidance to the other two planets. For the first half of October, Mercury floats about six degrees below, and slightly to the left of Venus before pulling back toward the Sun. Saturn starts the month near the horizon but quickly moves up to only a third of a degree from Mercury forming the closest appearance of two planets this year. Then, for five days, the Ringed Planet marches majestically up to pass about half a degree to the upper left of Venus. Binoculars are recommended. While all this is happening, Mars is very high due south, aligning with Castor and Pollux around Columbus Day. The Red Planet is now brighter than both the Gemini stars. The fat crescent Moon also passes by around this time. If you can get out before 6 a.m., be sure to check out the preview of the beautiful "winter" constella-tions. Evening observers are not left out as Jupiter dominates the southwestern sky until well after midnight. We can also say goodbye to the last bright star of summer as the thin crescent Moon passes near Antares, in Scorpius, the Scorpion, at the end of the third week of the month.