Friday, January 14, 2005

Deep Impact and Huygens on Titan....

It's been a good week for science - Deep Impact successfully launched on its mission to impact comet Tempel 1 on July 4th this year and the Huygens probe successfully landed on Saturns moon Titan this morning.

Deep Impact will crash a 370 kg impactor into comet 9P/Tempel 1 on the 4th of July. The main spacecraft will observe the impact and the results and many groundbased telescopes will observe the comet before, during, and after the impact to see what happens to the comet. We really only have some well educated guesses about what the insides of a comet look like. We know what kinds of material comets give off from spectroscopic observations of comets comae and tails, but what fraction of comets are ice and what types of ice? Fred Whipple first proposed the "Dirty Snowball" theory of the makeup of a comets nucleus back in about 1950 and we've been refining that model ever since. It has done a great job of allowing us to explain the behavior of comets including the non-gravitational affects we've seen in comets. We've also seen some comets close up thanks to encounters with comet Halley in 1986 and more recently with the Stardust spacecrafts flyby of comet Wild 2. This time is certainly exciting to be interested in comets! BTW, be sure to grab your binoculars and go look at comet C/2004 Q2 (Machholz) before it gets too faint.

The Cassini-Huygens spacecraft appears to have had another great success today when the Huygens probe entered the atmosphere of Saturns moon Titan and descended on a parachute, continuing to send data back to Cassini for relay to Earth for about 2 hours before Cassini set below the horizen from the probes view on the surface of Titan. We await the download of all the probes data from Cassini in the next few hours and by the time the evening news is on in the U.S., perhaps pictures of Titans mysterious surface will be the lead story.