"Huygens and Cassini Results at Titan"
Saturn’s largest
moon, Titan, remains an enigma, explored only by remote sensing from
Earth, and by the Voyager and Cassini spacecraft. The most puzzling
aspects include the origin of the molecular nitrogen and methane in its
atmosphere, and the mechanisms by which methane is maintained in the
face of rapid destruction by photolysis. The Huygens probe, launched
from the Cassini spacecraft, has made the first direct observations of
the lower atmosphere and the moon’s surface. The Huygens probe carried
six experiments to measure atmospheric structure, winds, chemical
composition and optical properties of the atmosphere and the aerosols,
and surface properties. The probe reached the upper atmosphere of Titan
on January 14, 2005, and landed softly on the surface after a 2.5 hour
descent. Unexpectedly, it transmitted data from the surface for 69
minutes giving additional clues about the surface composition and
morphology.