The European Space Agency's Huygens probe, carried millions of miles to Saturn on board the NASA Cassini space craft, has completed its final series of checks before separation. The check up, its sixteenth, found the probe in good health, according to the ESA.
The Huygens probe will detach from Cassini on Christmas day, and drop into orbit around Titan, Saturn's biggest moon. On 15 January 2005 it will begin its descent into Titan's atmosphere, an event that might even be visible from Earth, provided you have a decent telescope, and are in the right place at the time.
The probe has been designed to reveal more about the surface of Titan. Shrouded in its thick, cloudy atmosphere, the surface of the moon has been a mystery until very recently. Detailed radar images captured by Cassini as it swung past the rocky world delighted astronomers, but did not reveal much about the composition of the landscape.
In October, as scientists counted down to Cassini's closest approach to Titan, Professor John Zarnecki from the Open University, lead scientist for the Science Surface Package on the Huygens Probe, said his team is looking forward to finding out what kind of surface is under all the smog. "In other words we want to know if our instruments will land with a splash or a thud!"
The Huygens probe is named for Christiaan Huygens, the Dutch astronomer who discovered the moon. It measures 2.7 metres across and is built like a shellfish: its hard shell designed to protect its delicate instruments from the heat of entry into the atmosphere.
There are two parts to the probe - the entry assembly module and the descent module. The former carries the thermal protection, and the controls to manoeuvre the craft after it separates from Cassini. The descent module contains the scientific instruments. Three parachutes will slow the craft on the way to the surface. ®
