
Image: Aynur_zakirov/Pixabay/Reproduction
Last week, NASA’s InSight spacecraft detected the largest earthquake ever recorded on Mars so far. The magnitude 5 quake took place on May 4 and lasted about 30 minutes – much longer than earthquakes last on Earth.
This, however, was not the longest earthquake ever recorded on the red planet. In August 2021, InSight recorded a magnitude 4.2 tremor that shook the ground for 90 minutes. Until then, this was considered the largest of the 1,313 earthquakes ever detected by the probe, which has been operating since November 2018.
Earthquakes there are different
On Earth, earthquakes are the result of the movement of tectonic plates, which collide and release enormous amounts of energy, shaking the surface. But this is unique to us.
There are no tectonic plates outside here, which has led scientists to suggest that Martian earthquakes are caused by the cooling of the planet’s interior. Basically, the materials that exist there end up contracting over time, increasing the external stress, which is released through fractures in the crust. This generates less intense shakes than those seen on Earth, but much longer.
Analysis of earthquakes detected by InSight can help scientists understand details about the red planet’s interior. As seismic waves pass through material in the crust, mantle and core of Mars, they change. Such changes allow seismologists to determine the depth and composition of the layers.
This kind of study doesn’t just elucidate questions from Mars, but from all rocky worlds, which also includes Mercury, Venus, Earth and the Moon itself.