Mars ‘not as dead’ as it might seem

Most of the seismic activity detected on Mars by the InSight mission shows that the red planet is “not as dead” as it might seem, as it moves like Earth or Venus.

The images of the desolate surface of Mars, obtained by the spacecraft of this NASA mission are misleading because although “the main volcanic activity of the planet dates back to 3.5 billion years, it is not so dead”, says Clément Perrin, a physicist in the planetology laboratory. and Earth Sciences at the University of Nantes, France.

In fact, Mars is quite alive judging by the periodic tremors recorded since February 2019 by the InSight mission. Its seismometer, a high-precision instrument developed by the French National Center for Space Studies (CNES), is located more than 1,200 km from the Cerberus Fossae.

This is one of the “most recent areas of Mars, around 10 million years old”, “with open fractures, associated with volcanic activity”, explains Perrin, co-author of the study carried out by Simon Stähler, from the Polytechnic School of Zurich and published in Nature magazine.

These trenches, “true canyons several hundred kilometers long, up to a kilometer wide and a kilometer deep”, interest researchers for several reasons. A recent geological study showed, with the help of images captured by a probe in the orbit of Mars, the traces of volcanic activity from 50,000 to 200,000 years ago. According to Perrin, this is something “quite recent, something that we can have with inactive volcanoes in France”.

Questions about magma

The InSight mission brings a fresh look to this data, as well as confirming with its seismic study that the planet is very much alive, although we don’t see any active volcanoes.

“Before going to Mars with InSight, we thought it was a bit at the end of its life, with an underactive core,” says the physicist. The researchers expected to find a planet shaken by “small earthquakes coming from all sides”, a sign that it slowly contracts as it cools, as the Moon or Mercury does today.

But InSight’s seismometer recorded something else entirely, “mostly a source showing internal activity on the planet.” The machine detected earthquakes in the Cerberus Fossae area that scientists attribute to circulations of magma, from molten rock, in the crust of Mars at depths of 15 km to 50 km.

“Although we still have a lot to learn, the evidence for possible magma on Mars is intriguing,” according to Anna Mittelholz, a postdoctoral researcher at the polytechnic of Lausanne (Switzerland), cited by the university.

Stähler wonders, for his part, if “what we see are the last traces of activity in a formerly volcanic region or if magma is moving eastward and a new eruption zone.”

To get to the answer, it will be necessary to quickly replace the InSight mission, whose seismometer is expected to stop working in the coming months. Your solar panels, covered in dust, will no longer produce enough electricity to run.