Spiders on Mercury!
MESSENGER, the probe that passed Mercury recently, have released lots of images and made some scientific announcements, too. One striking image was this one:
This is an image of part of a vast region on called Caloris Basin. The cracks, called The Spider by the MESSENGER team, are like nothing seen before. Caloris Basin is an impact feature, and it seems something large hit Mercury a long time ago,. The impact carved out a hole, which filled with molten rock, and over time, the floor of the basin cracked.