The American’s have hyped this up a bit, ‘Valentine encounter for Stardust and comet’ when strictly speaking (if you follow GMT/UTC) then it’s the day after valentines. But hey, I guess if it gets people interested, why not.
The Deep Impact spacecraft originally flew past the comet back in July 2005 and launched a projectile at the comet. The scientists wanted to create a crater and launch material into space, photograph it and figure out what the composition of the comet was, and whether it was any different under the surface. From this, they should be able to figure where the comet had formed. They never did get a decent shot of the crater though. It’s thought to be about 100m across and 30m deep. It was determined that the comet had formed somewhere in the Uranus to Oort cloud region and had ethane ices present. Ethane is fairly volatile meaning that the comet had to form along way from the Sun for it to be present. Therefore if we find future comets with ethane ices we can make the assumption that they formed in a similar region to Tempel 1.
Interesting fact! The impact event made the comet to outgas for nearly 2 weeks. During those two weeks the comet lost about 5 million kg of water and 10 – 25 million kg of dust. Pretty impressive for a 7km x 5km comet!
It was then decided that Stardust, a mission that originally was designed to return samples of the coma of comet Wild 2, would head along and take another look at this comet. The mission was renamed Stardust-NExT (New Exploration of Tempel 1) and early on the 15th, she’ll fly by and grab a wealth of new science for us.
That’s a lovely image of the comet nucleus as taken by Deep Impact spacecraft. So what do we expect to see on the 15th? Well, obviously a nice 100m diameter crater. Scientists also want to know how the comet has changed over the years though. Has it outgassed anymore volatiles, have there been any landslides or other quirky events. Whatever is found it will again enhance our understanding of comets, how they form, how they live and ultimately it will help us refine our current understanding of the formation of the Solar System.
Keep and eye out for an update on the 15th. Pictures to be posted!