They took place on September 18 and December 24, 2021 and “ left two footprints more than 130 m in diameter on the surface of the planet Mars », explains the CNRS.
The second is even considered “ of the largest impact crater of the last centuries detected on a telluric planet, because its diameter of 150 meters exceeds the 120 meters of the crater Wabar, in Saudi Arabia “. On Mars, an impact of this size had never been detected by the Mars Reconnaissance Orbiter (MRO) mission in orbit for 16 years.
The meteorites crashed 3,500 and 7,500 km from the Insight seismometer landing site. “ By crossing seismic data from SEIS, for InSight, and CTX, MARCI and HiRISE cameras for MRO, the international teams of the two NASA missions were able to precisely locate, in time and space, these two events. “.
Eric Beucler, professor at Nantes University and co-author of the articles, explains that “ these are the first events for which surface waves are clearly visible. This makes it possible to determine the average structure of the crust of Mars between the point of impact and InSight “.
These measures “ are fundamental to understanding the evolution of Mars and had so far only been able to be done under the InSight station thanks to the body waves of earthquakes “.