Published by: 28/10/2022 – 00:33

Scientists observe planet mars Received an impressive Christmas present last year. On December 24, 2021, a meteorite hit its surface and caused a magnitude 4 earthquake. They were discovered by the InSight probe and its seismometer, which landed on Mars about 3,500 km from this location.

But the origin of this Martian earthquake was later confirmed only by the Mars Reconnaissance Orbiter (MRO). In orbit around the planet, it captured images of the newly formed crater within 24 hours of the event.

The image is striking: blocks of ice were thrown to the surface, excavating a crater 150 meters in diameter and 20 meters deep – the largest ever observed since the orbiter MRO was commissioned 16 years ago.

While it’s not uncommon for meteorites to hit Mars, “we never thought we’d see something this big,” Ingrid Dauber, who works on the InSight and MRO missions, said at a news conference Thursday. Researchers estimate that the meteorite itself must have been about 12 meters – on Earth it would have disintegrated in the atmosphere.

“This is the largest meteorite impact on Earth that we have heard since we did science with seismometers or seismometers,” explained AFP Philippe Lognon, professor of planetology who participated in two studies that resulted from these observations. In the journal science.

NASA has released the recording of the earthquake.

“Useful” ice cream

The valuable information gathered will help improve our knowledge of the Martian interior and its formation history. The presence of ice, in particular, is “surprising,” underscored Ingrid Dauber, co-author of both studies. “This is the hottest place on Mars, the closest to the equator, where we’ve seen ice.”

In addition to the scientific interest of this discovery for the study of the Martian climate, the presence of water at this latitude is “very useful” for future explorers, declared Lori Glaze, director of planetary sciences at NASA. “We want to land the astronauts closer to the equator because it’s warmer,” she said. However, the ice at the site could later transform into water or oxygen.

The impact of the meteorite was large enough to generate both body waves (propagating into the core) and surface waves (crossing the planet’s crust horizontally) – thus allowing detailed study of the internal structure of Mars. Thus the crust in which InSight is located is found to be less dense than the crust traveled from the collision site.

Also, in light of these data, “current models of the deep structure of the Martian mantle need to be re-analyzed a bit”, explained Philippe Lignonne of the Institut de Physique du Globe de Paris (IPGP).

Over 1,300 “marsquakes”

As expected, the InSight probe is operating in slow motion due to dust that has accumulated on its solar panels. Bruce Banner of NASA’s Jet Propulsion Laboratory said on Thursday that contact would be lost “in about four to eight weeks,” saying he was “saddened” but welcomed the mission’s success.

InSight detected more than 1,300 “marsquakes” in total — including some caused by small meteorites — and the data collected will be used by scientists around the world for years to come.

With AFP