The Zhurong robotic rover was sent to Mars as part of China’s Tianwen-1 mission. Launched into space in July 2020, the rover landed on the surface of the Red Planet on May 15, 2021. The rover was sent to a large plain in the northern hemisphere of Mars called Utopia Planitia, near the border between the lowlands where landed and the highlands to the south.
This region was chosen because it is suspected to be close to ancient coastlines and other interesting geographic features to look for evidence of water or ice. A large mass of subterranean ice was identified in a nearby sector of Utopia Planitia in 2016 by radar from NASA’s MRO space probe in orbit around the planet.
After landing, the Zhurong rover drove nearly two kilometers to the south, taking pictures of rocks, sand dunes and impact craters, and collecting data obtained by underground penetrating radar.
Underground penetrating radar detects subsurface features by sending electromagnetic pulses that reflect off underground structures it passes through. The Zhurong rover uses two radar frequencies: a lower one that goes deeper (about 80 meters) with less detail, and a higher one that shows more detailed features but only goes down to about 4.5 meters.
The researchers hope that the data obtained from the Martian subsoil will help to clarify the geological history of the planet, find out what the previous climatic conditions were and discover masses of ice or liquid water, current or past.
A “selfie” taken by the Zhurong robotic rover showing it next to its landing pad. The photo was taken with a wireless camera. (Photo: Chinese National Space Administration. CC BY-NC)
The data analysis carried out by Yi Xu’s team, from the University of Science and Technology in Macao, China, made it possible to detect several subterranean structures in the Martian subsoil that were identified as buried impact craters, as well as other features of less clear origin. .
Yi Xu and his colleagues found no evidence of water or ice in the top five meters of soil. Radar images of the deeper structures revealed layers of sediment left behind by past flooding and deposition events, but also found no evidence of present-day water. This does not exclude the possibility that there is water deeper than 80 meters up to which the radar reaches.
The study is titled “Martian soil as revealed by the ground-penetrating-radar at the Tianwen-1 landing site”. And it has been published in the academic journal Geology. (Fountain: NCYT by Amazings)