Scientists have been using rovers on Mars to search for anything that could indicate the possibility of life on the Red Planet and explore its geological properties. In 2017, the Curiosity Mars Rover discovered ancient mud cracks on Mars, located in the soil in Gale Crater. Based on the photos of a coffee table-sized rock nicknamed “Old Soaker” captured by the Curiosity Mastcam, scientists saw that the rock was covered in a crisscross pattern of polygons, which incredibly resemble cracks that are found on Earth.
Throughout the year, geologists from the California Institute of Technology, Caltech in Pasadena, conducted analyses on the geological features on the Martian surface. Now, they can confidently confirm that the mud cracks on Mars are remnants of a lake that disappeared up to 3.5 billion years ago.
The team published their findings last week in the journal Geology. The study poses evidence that the mud cracks on the Martian surface are desiccation cracks, formed due to wet sediment being exposed to air.
“We are now confident that these are mud cracks,” lead author Nathaniel Stein said in a statement by The Geological Society of America.
Stein and his colleagues referred to the Curiosity rover in order to obtain as much data as possible that could give more information about the physical appearance and the chemical composition of Old Soaker. The team analyzed it in detail using the Mastcam, Mars Hand Lens Imager, ChemCam Laser Induced Breakdown Spectrometer (LIBS), and the Alpha-Particle X-Ray Spectrometer (APXS), as per the press release.
“The Curiosity Rover is an amazing tool because it is acting as a robotic field geologist, piecing together the clues left from an ancient lake system,” Stein told Newsweek.
According to the data, the mud cracks found on the rock in Gale Crater were formed by ancient sediment which accumulated over time as the lake was drying up. The analysis concluded as well, that those cracks formed as they were exposed to air, denying the possibility of it being formed by heat or the natural flow of water, according to the statement.
However, Old Soaker wasn’t discovered at the edge of Gale Crater. Instead, it was found closer to the center of the ancient lake. Curiosity Rover found the slab of rock in the Sutton Island member of the Murray formation, according to the study. The study, based on this, indicates that the lake levels oscillated dramatically throughout time.
The authors also point out in the paper, that the mud cracks on Mars “indicate a transition from longer-lived perennial lakes recorded by older strata to younger lakes characterized by intermittent exposure.”
Stein also explains that the mud cracks discovered by NASA’s Curiosity Rover “are exciting because they add context to our understanding of this ancient lacustrine system.” Continuing to study geological properties of the Red Planet may provide answers on what caused the liquid water to disappear from the Red Planet.