The tremors were detected by the space agency’s InSight lander, which touched down on our planetary neighbor back in November 2018. Insight’s purpose is to learn more about Mars’ interior in order to give scientists a better idea of how the planet was shaped. If scientists are able to acquire knowledge on that subject then they’ll better understand why rocky planets form, and subsequently may be able to learn which of those planets have a greater chance of supporting life.
This past Thursday, NASA revealed that Insight’s seismometer detected “two sizable quakes.” Those happened on March 7th and 18th, in an area called Cerberus Fossae, which is where two previous quakes had occurred. The most recent two recorded magnitudes of 3.3 and 3.1, which are weaker than the two that had happened before (those were 3.6 and 3.5), but they’ve actually been more useful in giving scientists a better idea of the planet’s interior.
“Over the course of the mission, we’ve seen two different types of marsquakes: one that is more ‘Moon-like’ and the other, more ‘Earth-like,’” said Taichi Kawamura of France’s Institut de Physique du Globe de Paris. “Interestingly, all four of these larger quakes, which come from Cerberus Fossae, are ‘Earth-like.’”
Something that all four quakes also share in common is that they occurred during the Martian northern summer. Note that a Martian year is equal to slightly less than two years on Earth. We inform you of this not to pad out the article, but because winds during that time of year are calmer, which provides a more conducive environment for scientists to hear seismic activity.
“It’s wonderful to once again observe marsquakes after a long period of recording wind noise,” seismologist John Clinton said.
It’s believed that Mars, unlike Earth, lacks tectonic plates. Instead it looks like its volcanically-active regions are responsible for the events. NASA adds that the InSight has detected more than 500 quakes to date.