Mars, due to its weak atmosphere and proximity to the asteroid belt of our solar system, is far more vulnerable than Earth to colliding with space rocks – one of many differences between the two planetary neighbors.
With the help of NASA’s robotic InSight lander, scientists are now gaining a more complete understanding of this characteristic of Mars. Researchers reported Monday how InSight detected seismic and acoustic waves from four meteorite impacts and then calculated the location of the craters they left – the first such measurement anywhere other than Earth.
Researchers used observations from NASA’s Mars Reconnaissance Orbiter in space to confirm the crater locations.
“These seismic measurements give us an entirely new tool to probe Mars, or any other planet on which we can land a seismometer,” said Bruce Bannert, a planetary geophysicist at NASA’s Jet Propulsion Laboratory, principal investigator of the InSight mission. “
The space rocks InSight tracked – one landing in 2020 and the other three in 2021 – were relatively modest in size, weighing up to about 440 pounds (200 kg), with diameters of up to about 20 inches (50 cm) and leaving craters . Up to 24 feet (7.2 m) wide. They landed between 53 miles (85 km) and 180 miles (290 km) from InSight’s location. One exploded into at least three fragments, each of which dug its own pits.
Brown said, “We can link a known source type, location and size to a seismic signal. We can apply this information to better understand InSight’s full catalog of seismic events and on other planets and moons.” can also use the results.” .University planetary scientist Ingrid Dauber, co-authored study Published in the journal Nature Geoscience.
The researchers believe that now that the seismic signature of such impacts has been discovered, they hope to be further contained in InSight’s data going back in 2018.
The three-legged InSight – its name is short for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport – landed in 2018 in a vast and relatively flat plain north of the Martian equator called Elysium Planitia.
“The Moon is also a target for future meteor impact detection,” said Rafael García, a planetary scientist at the ISAE-SUPAERO Institute of Aeronautics and Space at the University of Toulouse and lead author of the study.
“And it may be the same sensor that will do that, because InSight’s additional sensors are currently integrated into the Farside Seismic Suite instrument for flight to the Moon in 2025,” Garcia said, referring to an instrument to be placed near the Moon. The side of the lunar south pole is permanently facing away from the Earth.
Mars is almost twice as likely to hit Earth with a meteorite in its atmosphere—the name of a space rock—before hitting the surface. However, Earth’s atmosphere is much thicker that protects the planet.
“So meteorites usually break up and disintegrate in Earth’s atmosphere, creating fireballs that rarely reach the surface to form a crater. Compared to Mars, hundreds of impacts hit the planet’s surface each year.” Craters are forming,” Dabur said.
The atmosphere of Mars is only 1 percent thicker than that of Earth. The asteroid belt, an abundant source of space rocks, lies between Mars and Jupiter.
The scientific goals set for InSight prior to the mission were to investigate the internal structure and processes of Mars, as well as to study seismic activity and meteorite impacts.
InSight’s seismometer instrument established that Mars is seismically active, detecting more than 1,300 marsquakes. In research published last year, seismic waves detected by InSight helped to understand the internal structure of Mars, including the size of its large liquid metal core, the thickness of its crust and the first estimates of the nature of its mantle.
© Thomson Reuters 2022
