Hi. I’m a grad student who is co-author on a paper that just came out in Geology last week. It was very exciting to be a part of such an important project! The Mars Orbiter Camera found two locations on Mars where gullies had formed new bright deposits between images! Since gullies are thought to form with liquid water (either from the subsurface or surface), these new deposits were thought to be evidence of very recent (within the past 10 Earth years), liquid water on the martian surface.

A team of scientists at the United States Geological Survey used two HiRISE stereo images to create a very high-resolution topography model of the crater that contains one of the bright deposits. Our team at UA used this model to examine whether the bright deposit in the Centauri region is more likely formed by a water-rich or a completely dry flow. Our results show that a completely dry flow could explain the deposit’s location and shape. Since it is very difficult to produce liquid water on the surface of Mars today, our work suggests that this bright deposit was formed without water. This does not mean that the gully that the deposit is in formed without water or that water never existed on the martian surface. Our work is just relevant to the recent bright deposit we studied.

HiRISE images show similar bright deposits around Mars. I am studying these deposits to look for one that cannot be explained by a dry flow alone. Finding one would mean that liquid water might be reaching the surface today, which could help NASA figure out where to look for past and present life on Mars!