By Michael Irving
October 17, 2023
https://newatlas.com/space/mars-orbiter ... marsquake/
NASA’s InSight lander was deployed to listen out for seismic activity on Mars, and last year it picked up a marsquake so big it was suspected to be from a meteoroid impact. Now, thanks to the cooperation of all agencies with orbiters around Mars, the source has been tracked.
On May 4, 2022, InSight detected a marsquake with a magnitude of 4.7 – the strongest ever seen on Mars. Designated S1222a, the quake was five times stronger than the next-strongest, and released the equivalent combined energy of all other marsquakes it detected over its five-year lifespan.
Mars doesn’t have any active plate tectonics, so it wasn’t thought capable of producing quakes this powerful. As such, scientists suspected that S1222a was the result of a meteoroid striking the surface, which is a common occurrence that produces similar seismic waves. Based on its power, such an impact would have produced a crater measuring at least 300 m (984 ft) wide – so to put the matter to bed, the entire planet was scoured for any new craters that size or larger.