Back in January 2017, NASA’s Curiosity Mars Rover spotted some ancient mud cracks in the Martian soil inside Gale Crater. The pictures of the cracks identified on Mars’ surface were analyzed closely by researchers who now claim that the cracks are indeed evidence of ancient lakes that might have dried up about 3.5 billion years ago.
The new study conducted by geologists at the California Institute of Technology (Caltech) in Pasadena has found that the cracks are desiccation mud cracks which could have formed when wet sediment was exposed to the air. The study provides further evidence of what the climate on Mars may have been like in its ancient past.
For the purpose of the study, the researchers studied the mud cracks which were found on a coffee table-sized slab of Martian rock nicknamed “Old Soaker.” They used data obtained from the Curiosity rover as well as from other tools, including the Mars Hand Lens Imager, Alpha-Particle X-Ray Spectrometer (APXS) and the ChemCam Laser-Induced Breakdown Spectrometer (LIBS) to study both the physical appearance and the chemistry of the rock.
After analyzing the rock, the research team concluded that the cracks were formed by exposure to air, rather than heat or the flow of water. Furthermore, the shape of the cracks suggested the occurrence of a single drying event on the planet instead of multiple cycles of the planet getting wet and drying over.
The cracks’ position closer to the center of the ancient lake bed rather than the edge also suggests that the lake levels changed often, rising and falling dramatically over time.
Nathaniel Stein, the lead study author, said the mud cracks are exciting because they add context to their understanding of the planet’s ancient lacustrine system. He added that the mud cracks show that the lakes in Gale Crater had gone through the same type of cycles that is observed on Earth.
The study has been published online in the journal GeoScience World.