Since 2018, more than 1,300 tremors have been recorded on Mars by the InSight mission’s seismometer, but these were relatively weak or occurred deep within the planet. Therefore, these only provided information about Mars’ core and mantle, but said little about its crust, as the university announced Thursday.
Thanks to the impact of two meteorites on Mars, researchers were for the first time able to evaluate the space waves propagating across the planet’s surface. It turns out that the shell is probably configured differently than expected.
As ETH Geophysics Institute Senior Assistant Doyeon Kim wrote in a study published in the journal Science, only one spot measurement has so far been available under the InSight terrain vehicle. Three layers of crust were detected.
Surface waves, now evaluated for the first time, paint a different picture as Kim continues to write. On average, the Martian crust between the impact zones of meteorites and the seismometer, located at a distance of about 3500 and 7500 kilometers, respectively, has a very smooth structure. In addition, their densities are higher than spot measurement.
ETH researchers are unable to provide a definitive answer as to why the average velocity of the currently observed surface waves is much higher than previous point measurements under the Mars probe.
For example, the crustal structure just below the probe might be considered untypical for Mars: it might have been uniquely formed, for example, by a meteorite impact.
Researchers expect more results soon. Because in May 2022, the probe observed the largest Mars earthquake ever with a magnitude of 5. Surface waves were also recorded, according to ETH’s statement.
This jolt came just in time before NASA’s InSight mission ended – the probe’s power began to run out. “The initial analysis of the data confirms the researchers’ findings from the two meteorite impacts.”
(SDA)