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26 September 2003

Mars Mania Mobs the McCarthy Observatory

by Monty Robson

On occasion the news media in this country inform the public about a happening in the natural world. They informed people so well about this year’s favorable opposition and close approach of the planet Mars that it created a new wave of Mars Mania. As a result the John J. McCarthy Observatory ¹ was mobbed with visitors eager to get a close-up view of the mysterious red planet. In the four weeks ending 12 September 2003 more than a thousand folks of all ages and descriptions stopped by the facility (this estimate is based on the 569 names added to the Guest Registry). The great majority of them came on Wednesday August 27^th, the day of closest approach.

Due to the overwhelming volume of calls and emails to the Observatory it was decided to make that Wednesday and the Monday before it public open house nights for viewing Mars. To accommodate everyone a half dozen telescopes were set up outside as was a video monitor. Inside, while people waited in line patiently to look through the 16-inch, there were other video monitors that beamed color imagery of the planet from the auxiliary refractor. The dedication and excellence of the Observatory’s all-volunteer staff was heartwarming as they ran telescopes, answered questions, and made sure the visitors had an exciting time and an educational experience.

Mars was closer to Earth on the 27^th than it has been in several tens of thousands of years. To have seen it brighter means you probably were a Neanderthal. For us to have been able to observe Mars this closely required a serendipitous conjunction of celestial events. First, Mars had to be very near opposition; meaning it is opposite the Sun in our sky and therefore would cross the local meridian at local midnight. Oppositions of Mars occur at intervals of just over 26 months. Then, Mars needed to be close to the Sun, perihelion, at the same time the Earth is far from the Sun, aphelion (remember Kepler’s First Law of Planetary Motion—the planet’s orbits are ellipses with the Sun at one focus of the ellipse). Well, most of these conditions were satisfied. Mars reached opposition at about 18:00 UTC on 2003 August 28^th. ² Mars reached perihelion on August 30^{th 3} and Earth passed aphelion on the Forth of July. The geometry of all this meant that at 09:46 UTC on 2003 August 27 the planets passed within 55,575,920 kilometers (34,646,365 statute miles) of each other. ⁴ A closer approach will not happen until the year 2287. ⁵ Mars was brighter in our sky than it has been in recorded history during this opposition because of its proximity to us. At close approach its apparent angular diameter was 25.127 arc seconds and it shined at an apparent magnitude of -2.88.⁶

So what? Well, nothing if you are not human, but to be human implies being curious about the natural world and Mars has aroused the curiosity of people for a long, long time. Mars has been known since prehistoric times. Early people observed that some "stars" seemed to wander through the night sky. The word "planet" comes from the Greek for wanderer. Mars is the Roman name for the planet the Greeks knew as Ares. The brightest star in the constellation Scorpius is known as Antares, or the rival of Ares.⁷ This is because both Mars and Antares have a similar red color and also because they seem to do battle in the sky. Just prior to opposition, a planet that is located farther from the Sun than the Earth seems to stop its eastward movement through the background stars and move to the west. This is known as retrograde motion and this is the apparent motion caused by the faster moving Earth passing the slower moving exterior planet. A while after this passage the planet seems to stop again and then resume its eastward motion. In 2001, Mars whizzed past Antares on March 4^th then stopped when it was 20 degrees from the star on May 11^th and headed back toward Antares, seeming to be on the attack. Opposition occurred on 13 June and by 19 July Mars was only about 5 degrees from Antares when it stopped and resumed its prograde or eastern motion.⁸ Mars, originally the Roman god of agriculture became their god of war, again maybe because of its color.

Mars again captured people’s imaginations after the 1877 announcement by Giovanni Schiaparelli that he had observed "canali" on Mars. In Italian canali simply means channels, but it was mistranslated into English as canals. As Carl Sagan points out in his timeless masterpiece Cosmos, canals on Mars imply that there must also be canal makers on Mars; the result -- Mars Mania. English writer H. G. Wells penned The War of the Worlds in 1897, a classic of science fiction. I read it this summer and now know why the radio version narrated by Orson Wells in 1938 scared so many people. Speculations about life on Mars were drastically dampened when images of Mars came back from our early space probes, the Mariner series, that showed a moon-like surface with no evidence of life. Contact with the surface happened in July of 1976 when two Viking spacecraft landed on Mars. Each was equipped with three experiments to look for life on the planet. I vividly remember initial data from these experiments met the criteria for life that was defined for the experiments prior to launch. Although these results are still debated by some, the consensus view seems to be that it was a chemical rather than a biological reaction that caused the false positive.

Mars made headlines everywhere with the 1997 announcement that scientists had found evidence for Martian life inside a meteorite. The Mars rock, designated ALH 84001, was found in the Allan Hills region of Antarctica and was the first meteorite discovered during a 1984 expedition. ⁹ Again, the debate concerning the possibility of life on Mars raged. It is a top priority of NASA to try to answer the question of whether Mars has or has had life. Currently there is an international fleet of spacecraft enroute to Mars to join the amazingly capable orbiters already on station; the Mars Global Surveyor and the Mars Odyssey. (Oppositions of Mars are the most efficient time to launch craft to the red planet.)

The debate over possible Martian life will continue, as it should. One lesson that astronomy can teach us is how precious our planetary home, with all of its inhabitants really is, the only place in the universe currently known to have life.

As demanding as this past month was for the Observatory’s staff with the public’s Mars Mania, scheduled visits from school classes, scout groups, senior groups, and families, we welcome being able to excite so many people. There were humorous moments; one late rainy evening as I was catching up on some correspondence a pair of ladies, maybe in their thirties, arrived so I began to give them a tour of the facility. One of them literally ran to the telescope once we were on the observing deck, put her eye to the eyepiece, and complained that all she could see was black. With all the diplomacy I could muster under the circumstances, I informed her there were at least three reasons I could think of for why she could not see Mars: the cover was on the telescope, the dome doors were closed, and the sky was overcast.

The facility was also kept busy with scientific and educational projects during this period of Mars Mania. A relatively new and critically important field of research deals with the threat we on Earth face from energetic cosmic impacts. This is a field that the McCarthy Observatory is well equipped to contribute to and one that we have developed some expertise in. On 2 September worldwide media headlines proclaimed an asteroid impact could occur in 2014. One headline went as far as to announce "Armageddon set for March 21, 2014". ¹⁰ So as soon as the weather cleared the Observatory’s telescopes found the newly discovered 2003 QQ47 and its position was reported with great precision and accuracy to the Minor Planet Center. As a result of our observations and those from others around the world we now know that there is no threat from this object for the foreseeable future.

Lisa Glukhovsky, a high school senior here and this year’s winner of the world’s largest science fair has begun a new project of asteroid discovery. In May, Lisa was one of the three top prize winners at the 2003 Intel International Science and Engineering Fair with her project, done at the McCarthy Observatory, "A Rapid, Accurate Method of Determining the Distance to Near Earth Asteroids". Lisa presented her project at this year’s Citizen Science Conference held in Pasadena by the Society for Amateur Scientists. I would like to take this opportunity to thank Shawn Carlson for all the warmth and courtesy he extended to this young lady during the conference, he really made her feel at home.

Another high school student completed an exciting project during this busy four-week period. Aaron Eisman, who commuted an hour each way to the Observatory, is now the only person in the world who knows the rotational period of the asteroid 21652. He is now finishing his paper on the project and will provide a copy of it to the Observatory’s Library. I am sure we will hear great things from both Aaron and Lisa in the future.

This time period also had several educational projects going on. We met the deadline for submission of an Educational Outreach Grant from NASA. We are developing an exciting new program entitled "Galileo’s Apprentice and The Starry Messenger". It is an inquiry-based, hands-on program targeted at grades six through nine that follows the sequence of the first book published on telescopic observations of the heavens -- Galileo’s Sidereus Nuncius. The program will become part of the public domain and will be distributed widely using several different media.

Three educational projects are ongoing that have to do with Mars. I am doing a Mars opposition and retrograde loop sequence with a film camera and a 135 mm lens. It turns out that this lens has a field of view just the right size to keep Mars on the plate from mid-June until mid-November, if the star Delta Aquarii is kept in the lower left portion of each image. The name of this star is Skat, a Wish, from the Arabic.¹¹ The other two projects are modern day recreations of observations that were done during the favorable Mars opposition of 1672, when Mars was also in Aquarius.

Parker Moreland is attempting to recreate the method that John Flamsteed, Britain’s first Astronomer Royal, used to determine the value of the astronomical unit (a.u.). In Derby, England on the night of 6 October 1672, for over six hours John Flamsteed labored at the telescope.¹² With a micrometer attached to the eyepiece he measured the angular separation between Mars and "three little stars" in the constellation Aquarius. He was looking for the elusive parallax of Mars. Parallax is the apparent displacement of an object’s position compared to a more distant background when viewed from different sites. Knowing the parallax angle and the distance between sites, the baseline, triangulation will produce the distance to the target. The rotating Earth would provide a baseline distance for his calculations since he and his telescope were seeing Mars from a different vantage point after six hours. We call this method of determining parallax angles the diurnal method. For a wonderful read regarding parallax, find a copy of Parallax, the Race to Measure the Cosmos by Alan Hirshfeld.¹³

Flamsteed determined that Mars showed a parallax angle of about 25 arc seconds so he then knew the distance between Mars and the Earth at opposition, when they are closest. Then by using Kepler’s Third Law of Planetary Motion, the distance to the Sun, the astronomical unit was derived.

Parker designed and built a modification to a commercially available eyepiece that turned it into a very accurate micrometer. He described the micrometer last year in the E-Bulletin (See "Remeasuring the Astronomical Unit") and complete information on it is still on our web site, www.mccarthyobservatory.org, in the JJMO Journal section under the Astronomy tab. Measurements of the angular separation between Mars and a star will be taken as soon as possible after nightfall and then repeated in the morning an equal time after Mars transits the local meridian as the first set preceded the transit. Parker’s results are very encouraging so far, stay tuned.

The other 1672 recreation project will attempt to measure the parallax of Mars to determine the value of the astronomical unit using simultaneous observations from sites separated by a long baseline. This is the method Cassini used; the converse of Flamsteed’s method. Italian born Giovanni Domenico Cassini, known to the French as Jean-Dominique Cassini or Cassini I, relocated to Paris and quickly became the first Director of l’Observatorie de Paris.

The oldest still functioning astronomical observatory, l’ Observatorie de Paris (Observatory Code 007) was built by the Sun King, Louis XIV. Cassini I became its first Director and was followed by his son and later descendents.

In February, 1672 the Académie Royale des Sciences, with urging from Cassini, sent an astronomical expedition, led by Jean Richer, to the island of Cayenne in what is now known as the South American country of French Guiana. Richer was charged with completing a long list of observations, including making simultaneous observations of the position of Mars with Cassini back in Paris. These observations allowed Cassini to calculate the value of the a.u. The values Flamsteed and Cassini came up with were in very close agreement. Van Helden thinks that this number, ~87 million miles, is not supported by the data or the calculations these men used, but he does credit them with setting a new lower limit on the distance to the Sun, thus greatly expanding the size of the solar system.¹⁴

Both of our historical projects are in progress for their educational value and their challenges, not for any scientific value. If we want to know the distance to Mars this day in age we could ask JPL’s Steve Ostro to radar range the planet and could expect results in the sub-meter accuracy range.

Our Cassini project involves taking simultaneous CCD camera images of Deimos, the outermost moon of Mars, with imaging partners around the world. We are using Deimos as the target (at the suggestion of Jim Ostiguy of the Rhode Island astronomical society, Skyscrapers) because the light from the background stars required to determine the position of Mars would be overwhelmed by the brightness of the planet. Our primary imaging partner is a group of students and their mentor and teacher Mogens Winther from the Amtsgymnasiet i Sønderborg, a high school in Denmark.

Our experience is that it is not easy to image Deimos. It needs to be at or near its maximum separation from the planet to find it. This happens every fifteen hours or so. Also to image it, the telescope, we have found needs to be just the right angular distance from Mars. Too close and the planet’s glare hides the moon, too far away and either Deimos is not in the field of view or reflections from the planet are produced that make the moon impossible to find.

The above images are not simultaneous and therefore cannot be used to determine the parallax of Mars. To get simultaneous imagery of course the weather at both sites has to cooperate and so does everything else. When trying to image with Denmark there is a very narrow window of opportunity for success since Mars is just rising for us but it is close to setting in Denmark. If and when simultaneous images are recorded software will calculate the position of Deimos. This is done by comparing its position to the position of the background stars. Star positions are provided by star catalogs, we use the large A2.0 catalog from the United States Naval Observatory (the USNO A2.0 contains positional information for over 500 million stars). The software position will be expressed in terms of equatorial celestial coordinates. One set of coordinates will be subtracted from the set of the corresponding image and a little math will produce the parallax shift. This very small angle will continue to get smaller as Mars gets farther from us. Last week, for example, we expected to see about 20 arc seconds of parallax from a pair of images taken from here and Denmark at the same time. Again, please stay tuned, if successful, you will hear it here first.

We at the McCarthy Observatory welcome any questions you may have and are always thrilled to work with other astronomical facilities and interested individuals on collaborative projects.

References and Notes

1. The John J. McCarthy Observatory (Observatory Code 932) located on the campus of the New Milford High School in New Milford, CT is the flagship project of the Western Connecticut Chapter, Society for Amateur Scientists and is the world’s most accessible observatory. Primarily an educational facility that uses the multifaceted science of astronomy to excite young people to the joys of learning, it is also a full-fledged research institute. Contact information: P. O. Box 1144, New Milford, CT 06776; telephone/fax: 860 354-1595; www.mccarthyobservatory.org; email: mail@mccarthyobservatory.org.
2. Observer’s Handbook 2003, The Royal Astronomical Society of Canada, University of Toronto Press, 2002, ISBN: 0-9689141-2-8, 91.
3. Ibid.
4. Derived from data from the JPL Horizons Ephemeris Generator, The Jet Propulsion Laboratory Solar System Dynamics Group, http://ssd.jpl.nasa.gov/cgi-bin/eph.
5. Observer’s Handbook 2003, 185.
6. JPL Horizons Ephemeris Generator.
7. Allen, Star Names Their Lore and Meaning, Dover Publications, New York, 1963, ISBN: 0-486-21079-0, 365 (corrected republication of Stechert’s Star Names and Their Meanings, 1899).
8. This information provided by the observatory’s telescope control software, TheSky, Software Bisque, Golden, CO, www.bisque.com.
9. Raeburn, Mars Uncovering the Secrets of the Red Planet, The National Geographic Society, Washington, 1998, ISBN: 0-7922-7373-7, 18.
10. The Independent of South Africa, 2 September 2003, from Reuters.
11. Allen, 53.
12. Van Helden, Measuring the Universe Cosmic Dimensions from Aristarchus to Halley, University of Chicago Press, 1985, ISBN: 0-226-84881-7, 136, an excellent well documented book by a great writer and thinker.
13. Hirshfeld, Parallax The Race to Measure the Cosmos, W. H. Freeman and Company, New York, 2001, ISBN: 0-7167-3711-6, one of the most enjoyable books I have read recently, brings out the colorful personalities and human side of many historical people, well written, entertaining, and enlightening.
14. Van Helden, 3, 129 -- 143, 161

Picture Credits

1. M. Robson, McCarthy Observatory
2. M. Robson, McCarthy Observatory
3. M. Robson, McCarthy Observatory
4. M. Robson, McCarthy Observatory
5. M. Robson, McCarthy Observatory
6. M. Winther, AGS, Denmark
7. M. Robson, McCarthy Observatory
8. M. Winther, AGS, Denmark; M. Robson, McCarthy Observatory

About the Author

Monty Robson is a husband and father and is a senior Captain for American Airlines. He is the President of the Western Connecticut Chapter, Society for Amateur Scientists and Director of the John J. McCarthy Observatory.