Mars is much more vulnerable than Earth because of its tenuous atmosphere and proximity to our solar system’s asteroid belt
Mars, due to its tenuous atmosphere and proximity to our solar system’s asteroid belt, is much more vulnerable than Earth to being hit by space rocks — one of the many differences between the two planetary neighbors.
Scientists are now getting a better understanding of this feature of Mars, with help from NASA’s robotic InSight lander. Researchers Monday described how InSight detected seismic and acoustic waves from the impact of four meteorites and then calculated the location of the craters they left behind — the first such measurements anywhere other than on Earth.
The researchers used observations from NASA’s Mars Reconnaissance Orbiter in space to confirm the crater’s location.
“These seismic measurements give us a completely new tool for exploring Mars, or any planet we could land a seismometer on,” said planetary geophysicist Bruce Banerdt of NASA’s Jet Propulsion Laboratory, the principal investigator on the InSight mission.
The space rocks that InSight has tracked – one landing in 2020 and the other three in 2021 – were relatively modest in size, estimated at about 200 kg, with a diameter of up to about 50 cm. craters up to about 24 feet (7.2 meters) wide. They landed between 53 miles (85 km) and 180 miles (290 km) from InSight’s location. One exploded into at least three pieces that each protruded their own craters.
“We can match a known source type, location and size to what the seismic signal looks like. We can apply this information to better understand InSight’s full catalog of seismic events and use the results on other planets and moons as well,” says brown. University planetary scientist Ingrid Daubar, a co-author of the study published in the journal Nature Geoscience https://www.nature.com/articles/s41561-022-01014-0.
The researchers believe that now that the seismic signature of such effects has been discovered, they expect to find more in InSight’s data, which dates back to 2018.
The three-legged InSight — its name short for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport — landed in 2018 in a vast and relatively flat plain just north of Mars’ equator called Elysium Planitia.
“The moon is also a target for future detection of meteor impacts,” said planetary scientist and lead researcher Raphael Garcia of the University of Toulouse’s ISAE-SUPAERO Institute for Aeronautics and Space.
“And it may be that the same sensors will do, as InSight’s spare sensors are currently integrated into the Farside Seismic Suite instrument for a flight to the moon in 2025,” Garcia added, citing an instrument located nearby. from the moon’s south pole on the side of the moon that is permanently away from Earth.
Mars is about twice as likely as Earth to have its atmosphere hit by a meteoroid — the name for a space rock before it hits the surface. However, Earth has a much thicker atmosphere that protects the planet.
“So meteoroids usually disintegrate and disintegrate in the Earth’s atmosphere, forming fireballs that only rarely reach the surface to form a crater. Compared to Mars, hundreds form somewhere on the planet’s surface every year. impact craters,” Daubar said.
Mars’ atmosphere is only about 1% as thick as Earth’s. The asteroid belt, an abundant source of space rocks, is located between Mars and Jupiter.
InSight’s scientific goals prior to the mission were to investigate Mars’ internal structure and processes, as well as study seismicity and meteorite impacts.
InSight’s seismometer instrument determined that Mars is seismically active, detecting more than 1,300 Marsquakes. In research published last year, seismic waves detected by InSight have helped decipher Mars’ internal structure, including the first estimates of the size of its large liquid metallic core, the thickness of its crust and the nature of its mantle. .