Found on Mars “dunes-ghosts”
Astronomers first found on Mars, the geological formations called “dune Ghost” — indentations on the surface of the planet which remained after the disappearance of the dunes. On the Ground of this structure was first discovered in 2016. Study results published in the journal of Geophysical Research: Planets.
Dunes may exist for a long time, but sooner or later disappear. If during this time at the bottom of them turned out to be hardened lava or accumulated sediment, after the destruction of the dunes in its place remains a hole. Such features are called “dunes-ghosts” because they remind us of frozen shadows once existed mountains of sand.
In the new work, the astronomers describe a number of potential dune ghosts, found using satellite imagery. All the authors found the order of 800 candidates for the role — 480 labyrinthus complex of intersecting canyons, and about 300 on the Hellas plain — a flat lowland age of about four billion years that have appeared in the crater.
The scientists write that in the cavities at the edges of such structures may still be ancient sand, isolated from the external environment for millions of years. The authors believe that this is a great place to search for traces of ancient life on the red planet, as it is known, for example, that in the dunes on the Land inhabited by microorganisms. Examine the size, shape and age of the dunes ghosts can help to understand how the climate on Mars has changed over time.