http://saturn.jpl.nasa.gov/news/even...0318/index.cfm

Titan Flyby - Mar. 18, 2006

Cassini to Study Titan's Atmosphere

The Cassini spacecraft will study the hazy atmosphere of Saturn's
moon Titan from the inside out during a flyby on March 18.

Cassini will transmit radio waves to Earth as it flies behind
Titan. The radio waves will pass through Titan's atmosphere,
revealing characteristics about the atmosphere's temperature,
structure and winds. Cassini has never done this before,
though NASA's Voyager 1 did a similar experiment in 1980.

During this flyby, Cassini also will bounce radio waves off
the surface of Titan for receipt on Earth. The reflectiveness
at different wavelengths will provide information about the
surface roughness and composition.