[iceman (Mike)]

The European Space Agency's Mars Express took this image of the rim of impact crater Huygens, which is 450 km (280 miles) across. By counting craters in the area, researchers have determined that Huygens was blasted out approximately 4 billion years ago, early on in Mars' history when the planet was being heavily bombarded like the rest of the planets in the Solar System. The rim seems to show a tributary system that could have been water runoff in the ancient Martian past.