Since the first close-up observation of Mars, we have witnessed peculiar polygonal ridges at every latitude on the surface of the Red Planet. And scientists now suspect that they all formed in different ways and want to find as many of these ridges as possible.
The starting point of this research, published in Icarus, was a curious region of Mars called Medusae Fossae, where the HiRISE camera on the Mars Reconnaissance Orbiter was able to shoot high-resolution images of a series of rock ridges, some as high as a 16-story building.
"Finding these ridges in the Medusae Fossae region set me on a quest to find all the types of polygonal ridges on Mars," lead author Laura Kerber of NASA's Jet Propulsion Laboratory said in a statement.
The team looked at this particular ridge formation and compared close-up images of similar regions studied by Curiosity, for example “The Garden City” on Mount Sharp.
These ridges seen in the Medusae Fossae region appear to have been produced by lava, which hardened underground. Over billions of years, erosion removed the softer rocks, exposing these thin, tall structures. On the other hand, the ridges seen by the NASA rover are believed to have been formed by mineral deposits, which is definitely different than the Medusae Fossae.
"Polygonal ridges can be formed in several different ways, and some of them are really key to understanding the history of early Mars," Kerber said. "Many of these ridges are mineral veins, and mineral veins tell us that water was circulating underground."
While Mars is not as big as Earth, it’s still got an area equivalent to 15 times the size of the United States. So the team is recruiting citizen scientists to help find more of these ridges.
If you want to help, you can register at the Zooniverse portal dedicated to Mars. This is one of several projects related to the Red Planet. So far, over 135,000 have helped explore the surface of Mars.