NASA's InSight robotic probe detects a likely "earthquake"

April 23 (Reuters) – NASA's InSight robotic probe has detected and measured what scientists think is a "marsquake," marking the first time that an earthquake is being recorded on another planet, reported Tuesday. Jet Propulsion Laboratory in California.

This breakthrough comes nearly five months after InSight, the first satellite specifically designed to study the depths of a distant world, lands on the surface of Mars to begin its two-year seismological mission on the Red Planet.

On April 6, the 128th Martian day of the LG, the lander's martian (or ground) lander recorded the low earthquake-qualified rumbling by JPL scientists.

It was detected by the French construction seismometer InSight, a sufficiently sensitive instrument to measure a seismic wave at half the radius of a hydrogen atom.

"We have collected background noise so far, but this first event officially inaugurates a new field: Martian seismology," said InSight principal investigator, Bruce Banerdt, in a press release.

Scientists are still examining the data to conclusively determine the precise cause of the signal, but the tremor appears to be coming from the inside of the planet, instead of being caused by forces above the surface, such as the wind.

"The high frequency level and the broadband are very similar to what we get from a disruption process. We are therefore very confident that it will be a marsquake, "explains Philippe Lognonné, professor of geophysics and planetary sciences at the University Paris Diderot in France and principal investigator of the seismometer InSight, in an email.

Nevertheless, such a small tremor in Southern California would be virtually lost among the dozens of small seismic cracks that occur every day.

"Our assumption is that it's a very small event relatively close, perhaps at a distance of 50 to 100 kilometers" from the LG, Banerdt told Reuters by phone.

A more distant earthquake would give more information about the interior of Mars, as seismic waves "would penetrate deeper into the planet before going back to seismometer," he said.

The size and duration of the earthquake also corresponded to the profile of a few thousand earthquakes detected on the lunar surface between 1969 and 1977 by seismometers installed by NASA's Apollo missions, said Lori Glaze, director of the global science division at headquarters of NASA in Washington.

The lunar and Martian surfaces are extremely calm with respect to the Earth, which experiences a constant low intensity seismic noise from the oceans and inclement weather, as well as earthquakes occurring along subterranean fault lines created by tectonic plates. moving in the earth's crust.

Mars and the moon lack tectonic plates. Their seismic activity is rather motivated by a process of cooling and contraction that causes an increase in stress and becomes strong enough to break the crust.

Three other apparent seismic signals were detected by InSight on March 14, April 10 and 11, but they were even smaller and of more ambiguous origin, leaving scientists less certain that they were true marsquakes.

Lognonné said he was expecting InSight to detect an earthquake 50 to 100 times larger than the April 6 earthquake. (Report by Joey Roulette in Orlando, Florida and Steve Gorman in Los Angeles, edited by Peter Cooney)