Cassini to study Huygens landing site

A flyby scheduled for Saturday of Saturn's largest moon will use a visual and infrared mapping spectrometer to study a landing site of the Huygens probe while the area is in direct sunlight, NASA says.

It will mark the 40th flyby of Titan since the Cassini spacecraft reached Saturn on July 1, 2004.

Although technically a moon, Titan is larger than someplanets and its makeup most closely resembles that of early Earth. This visit will mark the spacecraft's closest orbit of the moon, snapping detailed pictures and taking measurements that scientists will use to study Titan's atmosphere, which is thought to be made of nitrogen and methane.

The Huygens probe first reached Titan three weeks after detaching from the Cassini orbiter on Christmas Day, 2004. The Huygens probe then sent data for about 90 minutes, which scientists used to help determine the moon's physical and chemical makeup.

The Cassini spacecraft is the second to study Saturn, following the Voyager missions in the early 1980s. But Cassini is going closer.

Cassini-Huygens is a joint mission involving NASA, the European Space Agency and the Italian Space Agency.

It's named for two 17th century astronomers, Holland's Christiaan Huygens and Italian Giovanni Domenico Cassini. They studiedSaturn through their telescopes and discovered its five largest moons. Huygens claimed the largest, Titan.