NASA announced on Thursday that its InSight probe, which analyzes geological activity on Mars, recently recorded “two strong and clear earthquakes” in the same region where the probe previously observed two considerable earthquakes in 2019. This points to an area seismically active on Mars – a place that looks dry and devoid of life on its surface, but may be active under the ground.
“The tremors of magnitude 3.3 and 3.1 originated in a region called Cerberus Fossae, further supporting the idea that this location is seismically active,” wrote NASA. The new earthquakes took place on 7 and 18 March.
(They are considered relatively mild earthquakes on Earth, but they are definitely noises that people can feel, depending on how close they are and the depth of the earthquake.)
Cerberus Fossae is an area on Mars with steep valleys that cut across ancient plains. Evidence of landslides abounds there, with stones perhaps displaced by recurrent tremors.
The InSight landing module has logged more than 500 earthquakes so far (it landed in November 2018), suggesting that there may actually be some volcanically active places in the Martian subsoil, perhaps hot molten rock (magma) moving and flowing as it does on Earth.
Underground magma may have even created the underground lake planetary scientists detected under the South Pole of Mars in 2018. “You need a heat source,” Ali Bramson, a scientist at the University of Arizona’s Lunar and Planetary Laboratory, told Mashable. in 2019. “What could cause this heat source?” Bramson asked. “The only thing we have really achieved is an underground magma chamber that had to be active recently.”
Now is prime time to register more Martian earthquakes. On Mars, the northern winter season can be deeply windy, which shakes the InSight seismometer and can make earthquake detection impossible. But now the winds have eased.
“It is wonderful to see marsquakes again after a long period of recording wind noise,” said John Clinton, a seismologist on the InSight team, in a statement.