Signs of Flowing Water on Mars 1 2 3 4 5 6 7 8 9 10 Impact Craters Before-and-after views of an impact site. The top image was acquired in 2002, the lower one in 2006. Details evident at the impact site show how the blast moved dust around and interacted with craters and other small obstacles on the ground. + Full image and caption     Jet Propulsion Laboratory    California Institute of Technology