The quakes had a magnitude of 3.3 and 3.1.

This is reported by NASA, which detected the quakes with a seismometer from Marslander InSight.

Cerberus Fossae
The two tremors originated in the same area where two fairly severe tremors were previously detected (with a magnitude of 3.6 and 3.5). This area is called Cerberus Fossae. The fact that four powerful quakes from this area have now been observed reinforces the idea that Cerberus Fossae is seismically active.

Volcanic activity
Earthquakes are caused, among other things, by plates sliding past each other. However, Mars has no tectonic plates. But the red planet does have volcanically active areas that can generate tremors.

The interior of Mars
InSight has already detected more than 500 quakes on Mars. NASA hopes to learn more about how Mars works from these quakes. The four more powerful quakes from Cerberus Fossae lend themselves very well to this, according to NASA.

Summer
The last two tremors from Cerberus Fossae, like the lion’s share of previously detected tremors, were seen during the summer in Mars’ northern hemisphere. Researchers had previously predicted that the seismometer would then function extremely well. That has everything to do with the wind. Although the seismometer is covered with a dome-shaped shield that protects against the wind, the instrument is so sensitive that the wind still creates vibrations that drown out some earthquakes. In the summer, however, there is less wind and the seismometer can therefore detect more tremors.

Temperature fluctuation
But not only the wind is a challenge. The enormous temperature fluctuations on Mars are also not cooperative. Near the lander, temperatures range from -100 degrees Celsius at night to 0 degrees Celsius during the day. These temperature variations cause the cable connecting the Mars seismometer to InSight to contract and expand. And that also causes noise in the data. But researchers have now come up with something: they are going to cover the cable with Mars soil. The shovel at the end of InSights robotic arm is used for this.

Extended
It should eventually lead to the detection of many more quakes and a more accurate picture of the composition of Mars. InSight will be given a little more time for that follow-up research; NASA recently extended the lander’s mission by two years. InSight will now remain active on Mars at least until December 2022.

That does not mean that InSight will be working continuously for the next two years. The lander is strongly dependent on the available amount of solar energy. At the moment, the solar panels are covered with dust – so they generate less energy – and Mars is also moving away from the sun. This limits the amount of solar energy generated. NASA expects more energy to be available after July; Mars then moves towards the sun again. Until then, energy must be used sparingly and so one instrument after another is currently being switched off. The seismometer also has to believe it; NASA hopes to be able to keep it operational for another month or two, but it will probably have to be temporarily shut down as well.

Update
Marslander InSight arrived on Mars in 2018. Unlike many earlier Mars landers, rovers and orbiters, the lander does not research the Martian surface, but what can be found underneath. The lander is equipped with various instruments for this purpose. The seismometer naturally appeals to the imagination. But the same goes for the Heat Flow and Physical Properties Package (HP3), which was supposed to look up to five meters below the Martian surface. That part of the mission unfortunately failed. –