NASA - National Aeronautics and Space Administration

Image right: Artist concept of Titan flyby. Image credit: NASA/JPL

Cassini flies near Titan on Aug. 31, 2007, gaining an opportunity to image the Huygens probe landing site and study the composition and geology of Titan's surface. This flyby also places Cassini on a course to conduct the closest flyby of the odd moon Iapetus that it will perform during the entire mission. On Sept. 10, Cassini will come about 1,640 kilometers (1,000 miles) from Iapetus' surface.

Iapetus is a world of sharp contrasts. The leading hemisphere is as dark as a freshly-tarred street, and the white, trailing hemisphere resembles freshly-fallen snow. Scientists want to know more about the composition of the dark material that coats Iapetus. They also want to learn more about Iapetus' distinctive walnut shape and the chain of mountains along its equator.