The Huygens probe remains on schedule to separate from the Cassini Saturn orbiter early on December 25, entering Titan’s atmosphere to parachute to the still mysterious surface. Whether the probe will land on organic goo, an ocean of liquid methane, ethane and nitrogen or a solid surface is still unknown.

The Titan approach goes like this: after separation, Huygens will coast for 20 days, arriving at Titan on January 14. The probe will encounter the atmosphere at an altitude of 1270 kilometers (789 miles); Huygens will decelerate to a landing speed of 5 meters per second before touchdown. According to this news release from Britain’s Particle Physics and Astronomy Research Council, the landing bump will be the equivalent of jumping off a chair onto the ground.

Image: Titan’s atmosphere – After entering Titan’s atmosphere, Huygens’ parachute system will be deployed for the 2-2½ hour descent, during which most of the scientific measurements will be made. This artist’s impression shows the Probe suspended from the stabiliser parachute passing through the clouds that are expected at around 20 km altitude. The descent will occur during daylight to provide the best illumination conditions for imaging the clouds and surface. Credit: ESA

And in a tantalizing comment, professor Ian Halliday, chief executive of
PPARC, adds this:

“Titan is a mysterious place and raises many scientific questions. Its thick atmosphere is mostly nitrogen, but there are also methane and many other organic compounds. Some of them would be signs of life if they were on our planet. Organic compounds form when sunlight destroys methane. If sunlight is continuously destroying methane on Titan, how is methane getting into the atmosphere?”