Earlier this month NASA lost contact with The Mars Global Surveyor. They are close to declaring the probe lost and an end to the longest and most successful mission in the history of Mars exploration. Among the Surveyor's many accomplishments, it showed that the "face on Mars" was nothing more than a pile of rock:
Face? What Face?
And among the many spectacular shots taken over the probe's ten year life-span, this one is probably my favorited. It shows the frozen Sea of Elysium, where dust covered plates of ice are all that remain of an ancient ocean.