In a press conference today, NASA announced the discovery of flowing water on the Martian surface. This declaration differs from previous discoveries that only provided evidence that water existed long ago on Mars. Using comparisons of high resolution imagery from August 1999 and September 2005, scientists identified geologic changes that are "what you would expect to see if the material were carried by flowing water." Michael Malin, of Malin Space Science Systems, said, "They have finger-like branches at the downhill end and easily diverted around small obstacles." Discovering the gullies was made possible by the Mars Global Surveyor, which was recently lost.