Many more meteorites fall on Mars than previously thought

According to the data received, on the Red Planet there are from 180 to 260 collisions per year, and objects falling on it can reach the size of a basketball, forming eight-meter craters in the soil. In general, depending on the size of the falling body, the frequency of collisions exceeds predictions by a factor of two to ten. And some of the new impacts detected by the InSight lander were large: for example, one study reported two large collisions 97 days apart that were large enough to each create a crater the size of with a football field.

"We expected collisions of this size to happen once every few decades, maybe even once in a lifetime, but here we have two such collisions just over 90 days apart,— said Ingrid Dauber of Brown University, who led one of the studies.

Dauber is skeptical that these collisions are just coincidence and suggests that it is more likely that the frequency of collisions on Mars generally higher than planetary scientists assumed.

In both studies, the SEIS seismometer installed on the Insight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) apparatus was used to detect shocks. InSight recorded seismic data during the four years that SEIS was active on the surface of Mars (December 2018 to December 2022). Separating the seismic shock wave from the collision from all the other seismic movements on the Red Planet is not easy, so Dauber's team compared the seismic data with images of the new craters seen from orbit by NASA's Mars Reconnaissance Orbiter (MRO) to link the tremors.

From MRO images, Daubert's team identified eight new impact craters that triggered the Martian earthquakes detected by SEIS. Six of these craters were located in the landing area of ​​”Insight”. in Elysium Planitia. The two larger collisions, 97 days apart, created craters much further away. These two events are the largest fresh collisions on Mars in the history of robotic exploration of the Red Planet.