Volume 41 No. 2 February 1, 2004 NEXT MEETING 7:30 p.m., Monday, February 2, 2004 Maturango Museum, 100 East Las Flores Avenue, Ridgecrest, California JANUARY 5 MEETING CLAS member Richard Rynne will bring DVDs of "Destination Mars" and "Mars, the Red Planet." These programs were first shown on the Discovery Channel. Included is a discussion of the prospects of a Martian journey. The claim is that "We could do it today!" The DVDs will be shown on the Museum's new digital projection system. We saw most of the first DVD at the January meeting, and it was very well done. We will continue with the second DVD. DATES TO KEEP IN MIND Monday, February 2, 2004: Regular CLAS Meeting at the Maturango Museum in Ridgecrest, 7:30 p.m. Wednesday, February 18. 2004: Deadline for next Skywatchers Newsletter Monday, March 1, 2004: Regular CLAS Meeting at the Maturango Museum in Ridgecrest, 7:30 p.m. No star parties in January or February, next star party in March STAR PARTY SCHEDULE FOR THE 2004 SEASON: No more star parties until March 2004. THE SKY IN FEBRUARY (Roger Brower) 1. Venus rises even higher in the evening sky this month. Look for it high in the Southwest just after sundown. 2. Saturn is still a fine evening object this month. Look for it in the East as soon as it gets dark. 3. Jupiter rises about 8:30PM at the beginning of the month and will remain a fine viewing object the rest of the night. 4. Mars still shines faintly in the southwest in the early evening. Hope everyone is seeing the fine images being beamed back from the surface. Look for them on NASA/JPL sites on the web. HANDBOOKS AND CALENDARS FOR 2004 ARE STILL AVAILABLE. The Royal Canadian Astronomical Society of Canada publishes both the Observer's Handbook and the Observer's Calendar. They have been received, and we will hold the price at $15.00 and $10.00. They will be available at the January meeting, or by arrangement with Roger Brower at 760-375-1181 or email brower@iwvisp.com. GREEN LASER POINTERS Green laser pointers are available at the low price of $70.00 each, if purchased by CLAS in quantities of ten. CLAS ordered, received, and distributed an initial order of fifteen. A second group of ten is on hand. Contact Roger Brower at 760-375-1181 if you want one or more. OUTREACH PROGRAM On Saturday evening, January 17 Chuck Morgan and Carroll Evans hosted a group of 30 Boy Scouts and parents, from Bakersfield. The Maturango Museum telescope was used to show them Saturn and the Orion Nebula. The last group got to see Jupiter and four moons also. The scouts had been camping and doing field trips based at Red Rock Canyon. ASTRONOMY NEWS FROM EARL TOWSON WEAK FORCE DETECTED THAT ACTS ON ASTEROID ORBITS: NASA News Release: 2003-163. NASA scientists have for the first time detected a tiny but theoretically important force acting on asteroids by measuring an extremely subtle change in a near-Earth asteroid's orbital path. This force, called the Yarkovsky Effect, is produced by the way an asteroid absorbs energy from the sun and re-radiates it into space as heat. The research will impact how scientists understand and track asteroids in the future. Asteroid 64 89 "Golevka" is relatively inconspicuous by near-Earth asteroid standards. It is only one half-kilometer (.33 mile) across, although it weighs in at about 210 billion kilograms (460 billion pounds). But as unremarkable as Golevka is on a celestial scale it is also relatively well characterized, having been observed via radar in 1991, 1995, 1999 and this past May. An international team of astronomers, including researchers from NASA's JPL in Pasadena, Calif., have used this comprehensive data set to make a detailed analysis of the asteroid's orbital path. The team's report appears in the December 5 issue of "Science." "For the first time we have proven that asteroids can literally propel themselves through space, albeit very slowly," said Dr. Steven Chesley, a scientist at NASA's Jet Propulsion Laboratory and leader of the study. The idea behind the Yarkovsky Effect is the simple notion that an asteroid's surface is heated by the sun during the day and then cools off during the night. Because of this the asteroid tends to emit more heat from its afternoon side, just as the evening twilight on Earth is warmer than the morning twilight. This unbalanced thermal radiation produces a tiny acceleration that has until now gone unmeasured. "The amount of force exerted by the Yarkovsky Effect, about an ounce in the case of Golevka, is incredibly small, especially considering the asteroid's overall mass," said Chesley. "But over the 12 years that Golevka has been observed, that small force has caused a shift of 15 kilometers (9.4 miles). Apply that same force over tens of millions of years and it can have a huge effect on an asteroid's orbit. Asteroids that orbit the Sun between Mars and Jupiter can actually become near-Earth asteroids." The Yarkovsky Effect has become an essential tool for understanding several aspects of asteroid dynamics. Theoreticians have used it to explain such phenomena as the rate of asteroid transport from the main belt to the inner solar system, the ages of meteorite samples, and the characteristics of so-called "asteroid families" that are formed when a larger asteroid is disrupted by collision. And yet, despite its profound theoretical significance, the force has never been detected, much less measured, for any asteroid until now. More information about NASA's planetary missions, astronomical observations, and laboratory measurements are available on the Internet at: http://neo.jpl.nasa.gov/ Information about NASA programs is available on the Internet at: www.nasa.gov (S Chesley et al. 2003 Science 302 1739). ODYSSEY STUDIES MARTIAN CLIMATE AND WEATHER CHANGES: News Release: 2003-165; December 8, 2003 - Mars may be going through a period of climate change, new findings from NASA's Mars Odyssey orbiter suggest. The amount of frozen water near the surface in some relatively warm low-latitude regions on both sides of Mars' equator appears too great to be in equilibrium with the atmosphere under current climatic conditions based on measurements of neutron emissions. "One explanation could be that Mars is just coming out of an ice age. "In some low-latitude areas, the ice has already dissipated. In others, that process is slower and hasn't reached an equilibrium yet. Those areas are like the patches of snow you sometimes see persisting in protected spots long after the last snowfall of the winter." Frozen water makes up as much as 10 percent of the top meter (three feet) of surface material in some regions close to the equator. Dust deposits may be covering and insulating the lingering ice, Feldman said. He and other Odyssey scientists described their recent findings today at the fall meeting of the American Geophysical Union in San Francisco. "A model that fits the data has three layers near the surface. The very top layer would be dry, with no ice. The next layer would contain ice in the pore spaces between grains of soil. Beneath that would be a very ice-rich layer, 60 to nearly 100 percent water ice." The iciest layer as a deposit of snow or frost, mixed with a little windblown dust, from a cold-climate era. The middle layer could be the result of changes brought in a warmer era: The ice down to a certain depth dissipates into the atmosphere. The dust left behind collapses into a soil layer with limited pore space for returning ice. Information from the gamma-ray spectrometer alone is not enough to tell how recently the climate changed from colder to warmer, but an estimated range might come from collaborations with climate modelers. Other Odyssey instruments are providing other pieces of the puzzle. Images from the orbiter's camera system have been combined into the highest resolution complete map ever made of Mars' south polar region. Temperature information from the camera system's infrared imaging has produced a surprise about dark patches that dot bright expanses of seasonal carbon-dioxide ice. "Those dark features look like places where the ice has gone away, but thermal infrared maps show that even the dark areas have temperatures so low they must be carbon-dioxide ice. One possibility is that the ice is clear in these areas and we're seeing down through the ice to features underneath."Information about the mission is available on the Internet at: http://www.spacedaily.com/news/extrasolar-03w.html SOLAR ACTIVITY AT 1000 YEAR HIGH: Geophysicists in Finland and Germany have calculated that the Sun is more magnetically active now than it has been for over a 1000 years. Ilya Usoskin and colleagues at the University of Oulu and the Max-Planck Institute for Aeronomy say that their technique - which relies on a radioactive dating technique - is the first direct quantitative reconstruction of solar activity based on physical, rather than statistical, models (I G Usoskin et al. 2003 Phys. Rev. Lett. 9121101) http://physicsweb.org/article/news/7/12/2 MEMBERSHIP INFORMATION Basic CLAS dues are $20.00 per year, which includes the Skywatchers Newsletter. As a benefit of membership you may also receive Astronomy Magazine and/or Sky and Telescope Magazine. The fee schedule is as follows: Basic membership $20.00 per year Membership with Astronomy magazine $44.00 per year Membership with Sky and Telescope magazine $53.00 per year Membership with both S & T and Astronomy $77.00 per year Send your check to: Roger Brower, Treasurer, China Lake Astronomical Society, P.O. Box 1783, Ridgecrest, CA 93556. PRESIDENT Earl Wilson (email zearlw@hotmail.com) VICE-PRESIDENT - Bruce Churchill - 760-375-7247 (email bchurchill@atsecure.net) SECRETARY Ted Hodgkinson - 661- 824-2738 (email longeyes@antelecom.net) TREASURER - 760-375-1181 (email brower@iwvisp.com) NEWSLETTER EDITOR - Carroll Evans Jr. - 760-375-5681 (email clevans@ridgenet.net) WESTERN AMATEUR ASTRONOMERS WEB SITE Meetings of the China Lake Astronomical Society are held at the Maturango Museum at 7:30 p.m. on the first Monday evening of each month, except when the first Monday is a holiday. SKYWATCHERS Newsletter of the CHINA LAKE ASTRONOMICAL SOCIETY POST OFFICE BOX 1783 RIDGECREST, CA 93556-1783 NEXT MEETING: 7:30 p.m., MONDAY, February 2, 2004 "Mars the Red Planet" AT THE MATURANGO MUSEUM, 100 EAST LAS FLORES AVE. CLAS WEB PAGE INDEX OF CLAS NEWSLETTERS