Scientists from the NASA InSight mission to Mars have announced the results of a ground-breaking seismic experiment led by scientists in the Department of Earth Sciences, Oxford.
In February 2021, the research team attempted to detect the entry, descent and landing of NASA’s MARS 2020 mission (Perseverance) using sensors carried on board the InSight spacecraft, which has been operating on Mars since 2018. This was the first time that a spacecraft on the surface of another planet had attempted to detect the arrival of another.
Prior to the landing, it was predicted that the most promising and potentially detectable signal would be from the impact of Perseverance’s balance masses with the surface. While the signal of the landing went undetected, the results published in Nature Astronomy reveal that this non-detection enabled the scientists to place the first constraints on a key geological property of Mars known as ‘seismic efficiency.’ This is the amount of energy converted from ground impacts, such as meteorites striking the planet, into seismic waves. Measurements taken during the landing window reveal a seismic efficiency of less than 3%, which has important implications for understanding the dynamics of impact processes on both Earth and Mars.
One of the craters produced by the impact of Perseverance’s balance masses with the surface, as imaged by the HiRISE instrument on the Mars Reconnaissance Orbiter.
Lead author Benjamin Fernando, graduate student at Oxford said, ‘This experiment is the first time anything like this has been tried on Mars and being able to ascertain an upper limit for seismic efficiency of 3% gives us valuable additional information about the physics of meteorite and asteroid impacts. The workflow that we have created will help us to conduct similar studies in the future, on both Mars and the other icy and rocky worlds of our Solar System.’
‘Seismic constraints from a Mars impact experiment using InSight and Perseverance’ is published in Nature Astronomy and can be accessed here: https://www.nature.com/articles/s41550-021-01502-0
Feature image: Perseverance touching down on Mars. Credit: NASA/JPL Caltech