Speaking of weird impact craters on Mars... Mars Express is a European Space Agency orbiter that's been snapping away at the Red Planet since late 2003. In August 2010 it took this picture of a bizarre feature on Mars:
[Click to impactenate.] I would've thought this was a canyon of some sort, but in fact it's an elongated crater! Most likely some large object broke up as it entered the atmosphere of Mars, striking the surface at a low angle and creating a series of craters that merged to form this strange thing. Unlike the triple crater I mentioned last time, this one is pretty frakkin' big: it's 78 kilometers (almost 50 miles!) long, 10 km (6 miles) wide at one end and 25 km (15.5 miles) wide at the other. Whatever hit here was pretty big, certainly over a kilometer across before it broke up. Probably several. In the ...
