Star Points for January, 2004; by Curtis Roelle Saturn: Wide Open and Downfield It would be a shame if anyone who was good all last year, and had then asked for and received a telescope for the holidays, didn't know where to begin pointing their new instrument. Often when people seek advice about purchasing a telescope for themselves or as a gift they mention the desire to see the rings of Saturn. Well, here's your chance. After putting on a fine show during the Summer and Fall Mars has all but slipped away. Fortunately for telescope owners, Saturn has now moved in to replace Mars' as the prime evening attraction for telescopes of all sizes. Saturn is now located north of Orion at the feet of the Gemini twins. Look about halfway between Orion's shoulder star Betelgeuse and the "twin stars" Castor and Pollux. It looks like a bright yellow-white star easily visible to the naked eye. There are three main factors conspiring to make the current apparition of Saturn one of the best in recent years. I will summarize them here. Readers of Sky and Telescope magazine should consult the December issue for an article written by Damian Peach for more details. Factor 1: Saturn reached opposition on December 31. This means that Saturn is now at its closest point to Earth for the coming year. At opposition Saturn rises around the time of sunset and "culminates" -- reaches its highest point in the sky -- near local midnight. As the weeks roll past Saturn will be rising earlier each evening and by early February the planet will be culminating in prime time before 10 p.m. This is according to the Sky & Telescope's supplementary publication, the "Star Gazer's Almanac '04." Unlike Mars, the change in Saturn's apparent size due to its increasing distance from us is less dramatic. Thus, you can watch Saturn over the next several months without noticing much in the way of apparent major shrinkage. Much like Jupiter Saturn is wrapped in darker "belts" and lighter "zones." However, the hues and contrast between Saturn's are more subtle than with Jupiter. To my eye the belts appear light brown whereas the zones are more cream colored. At the present time Saturn has more than thirty known moons and counting. A number of these are visible in amateur telescopes, depending on the telescope's size. By size I mean aperture, the diameter of the main lens or mirror. The bigger the aperture the more light is gathered and the fainter the objects that can be viewed. Almost any telescope will show you Saturn's brightest moon, Titan. Look for a yellowish "star" that remains close to the planet every night. Medium sized telescopes will show a few more moons, including Rhea, Tethys, Dione, and possibly Iapetus. Large telescopes may ferret out additional moons, including Enceladus, Mimas, and possibly Hyperion. Note that wide open rings such as we have now can make spotting moons more difficult because of the additional glare they produce. You might have better luck with the fainter moons several years from now when the rings are viewed more edge-on. Factor 2: Last April Saturn's rings were tilted at their maximum angle and best situated for viewing. This is still true today and the openness of the rings have increased Saturn's brightness because of the contribution of their illuminated surface area. There are three concentric main rings that are denoted from the outside going inward A, B, and C. The B ring is brightest and C is quite faint and transparent. This is most apparent where the rings cross in front of the planet. The ball of Saturn can be viewed through the C ring, but ring B is more opaque. With the current tilt medium sized telescope may show the dark narrow gap separating the A and B rings known as the "Cassini Division." Can you see it? If you can I would appreciate receiving an e-mail of your observation. Please include the size (aperture) and type (refractor, reflector, etc.) of telescope and the magnification used. The e-mail address can be found at the web page whose address is given at the end of this article. A second and narrower dark gap located closer to the outside edge of the A ring is visible in large amateur telescopes with high quality clean optics. This elusive gap is known as the "Enke Division." Large telescope owners are probably already aware of this feature. Factor 3: Saturn is well north of the Celestial Equator. This means that when Saturn culminates it will be very high in the sky overhead near the zenith. This is good for us in the northern hemisphere. The higher in the sky an object is, the less of our earth's distorting atmosphere lies between us and the object. This means that the target object appears sharp when focused and will quiver and undulate less due to poor seeing conditions caused by the convective air currents of our atmosphere. Another thing to look for when observing Saturn are shadows. You may be able to glimpse the shadow cast by the ring onto the ball of the planet. Likewise, you might also see the shadow cast by the ball on the part of the rings which pass behind the ball. Currently the Cassini spacecraft is approaching Saturn. Launched in October 1997 it is expected to go into orbit around Saturn this coming July. The "Huygens" probe, named after the 17th century Dutch scientist Christiaan Huygens, will study Titan's atmosphere by plunging into it. Another favorite object for new telescope owners is the moon. For anyone who looks its way the moon never ceases to amaze. Small telescopes and even binoculars reveal a wealth of detail involving mountain ranges, craters and the lunar marae or seas. But in order to identify them all you will need a chart or map. In my opinion the best moon map available is "The Earth's Moon" prepared by the National Geographic Society. It is clear, easy to use, and includes many craters and features that most other moon maps don't have. I bought the laminated version to keep dew and the dampness from the night from damaging the map. The biggest complaint I have about it is that the grid numbers and letters are in red and are therefore invisible at the telescope when using a standard red flashlight. Apparently it was designed for desk use rather than in the field. You can find this and other reference space maps in the "maps, globes & atlases" section at shop.nationalgeographic.com. A final footnote on Mars. As of this writing (Dec. 26) the latest Mars lander, the European Space Agency's Beagle II, remains silent. If so, then it is only the latest Mars flop and is in good company in that regard. This is because three out of the four most recent missions prior to it also experienced mission failures. Japan's Nozomi (Planet B) suffered a rocket failure causing it to recently limp past Mars, missing the planet entirely, and was four years behind schedule in doing so. Two U.S. missions were lost on arrival at Mars in 1998 and 1999. NASA's Mars Odyssey has been the only successful Mars mission since Pathfinder's famous mini-rover trundled around its landing site in 1997. Two more U.S. Mars missions are expected to arrive this month. The twin Rover missions have been named Spirit and Opportunity.