The newly spotted impressions of the croissant shape (marked with arrows above) on Mars give the scientists clues to the history of the Red Planet.
The forms known as "ghost dunes" are the hardened imprints of ancient sand dunes that have arisen as lava or sediment soaked and solidified the lower contours of the dunes, when the winds finally dispersed the sand above it negative space where the dune used to stand as a pit on the Martian surface While many images of the Red Planet have documented huge sand dunes, these new geological features were first discovered on Earth in 2016 and not until the beginning of the year on Mars
Using satellite imagery, the researchers discovered fields with ghost dune surface from two different regions on Mars: 480 potential dune shapes at Noctis Labyrinthus, a labyrinthine region of plateaus and canyons, and 300 in Hellas Planitia, a smooth 4 billion years ancient crater.The analysis of the size, shape and age of the ghost dunes k illuminate might the Martian climate throughout history, the team reported in Journal of Geophysical Research: Planets.
The team also says that pockets at the pit edges could still contain sand, which has been protected from the elements for millions of years. According to the researchers, this ancient sand would be an excellent place to look for the molecular evidence of life on Mars, as it has been shown that sand dunes on Earth support microbial life.