The European Space Agency is sponsoring a contest: if you think comets are cool, tweet about them! The winner gets a trip to Darmstadt, Germany -- ESA's operating HQ -- to celebrate 25 years of exploring comets.
There are rules, but they boil down to posting on Twitter about comets, using the "#coolcomet" hashtag, and providing an optional link to a non-text page (YouTube video, picture, etc.) that follows up. You have to be from a member country of ESA or the US to participate.
They are collecting all the tweets using TwapperKeeper, and you can see what others have done. They're getting lots of entries, so if you want to try, I suggest being clever. Think about different aspects of comets, something unusual, and why they're so interesting. The posts linked below might help get your unsublimated gases thawed.
Have fun! And if you win, send me a postcard from Darmstadt.
Image credit: Comet McNaught in the daytime from Chris North/Wikipedia