I saved this one from APOD before the Mars rovers landed and got all the attention. This is a shot captured from the Mars Global Surveyor, which orbited Mars. Considered interesting about this shot are the layers that you see on the hills. The layers around the hills are described as wide enough to drive a truck around, assuming that you had a truck and that it was on Mars and that you could start it and that you could drive it. The whole shot is about 3 kilometers across.