November 17, 2004
Louis A. Mayo
Raytheon and NASA-GSFC
"Titan: Earth's Real Sister Planet"
with bonus material on the Virtual Telescopes in Education Project
TALK ABSTRACT: -------------- Since Titan's discovery by Christiaan Huygens in 1655 (first named "Saturni Luna"), astronomers have been slowly uncovering the secrets of this strangely Earth like moon of Saturn. With the identification of a substantial atmosphere by Gerard P. Kuiper in 1944 including spectroscopic identification of methane, a number of atmospheric physical attributes began to be revealed through increasingly sophisticated ground-based instruments and techniques. In 1980 and 81, around the end of Titan's northern winter season, the Voyagers I and II spacecraft provided a wealth of new information about Titan's atmosphere including identification of its haze layer, atmospheric density and temperature models, atmospheric composition, magnetic field measurements, and high-resolution image mapping of its disk. Since that time, the Voyager datasets have continued to yield new discoveries about the nature of Titan's atmosphere. HST and ground-based optical, IR, and radio studies have been conducted yielding information on temporal variations in Titan's atmosphere and providing the first glimpses of its surface. It is now generally believed that Titan has seasons, clouds, smog, rain, and lakes as well as a rich pre-biotic atmospheric chemistry. Limited, low-resolution imaging of the surface has been performed via near-infrared observations between 1 and 2 microns where methane absorption windows exist. These images may be suggestive of surface features though few conclusive statements about the surface can be made at present. The Cassini spacecraft and Huygens probe, now in orbit around Saturn are providing new observations with more sensitive and capable instruments through 44 flybys of Titan over the next four years and a probe entry in January 05. Undoubtedly, this will greatly advance our understanding of Titan in the same manner as Voyager did over 20 years ago and set the stage for future missions to this most intriguing of planetary satellites. Additional material will be presented on the Telescopes In Education Project.