NASA's Phoenix lander should complete its 10 month, 400 million mile journey tonight at around 0:52 BST. It's looking for organic molecules in the frozen soil near the northern pole, the presence of which would signal the possibility that Mars was or perhaps is habitable by primitive organisms. If interested you can watch here
http://www.nasa.gov/multimedia/nasatv/ from 11:30pm. There won't be much to see, but you might catch the first pictures if you stay up for a couple of hours. Mission is scheduled to last just 3 months at which point the Martian winter will freeze the crafts electronics.
Thanks for posting, I'm bummed out at missing this but I'm sure NASA will repeat at some point. Cheers
