GMU Space Sciences Seminar

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:
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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.