For the first time .. NASA records the sound of meteorites crashing on Mars and monitors the impact craters resulting from them
Since 2018, NASA's InSight mission to Mars has recorded seismic waves from more than 1,300 earthquakes in its quest to explore the inner structure of the Red Planet.
But the internal vibrations of our planetary neighbor weren't the only thing that InSight's seismographs detected, as the instruments also picked up the impact of space rocks smashing into Martian soil.
In new research published in Nature Geoscience, scientists used data from Insight to detect and identify four high-speed meteorite impacts, then tracked the resulting craters in satellite images from NASA's Mars Reconnaissance Orbiter.
Not only does this help scientists understand the impact processes that continue to shape Mars' geology, but it also shows how collecting seismic data can reveal information beyond the parameters of an expected mission. This may help guide future exploration of other worlds.
The lander, "Insight", heard and detected the vibrations of four space rocks as they hit Mars over the past two years.
These are not only the first effects detected by the spacecraft's seismometer since landing on the Red Planet, but also the first time that seismic and sound waves from a collision have been detected on Mars.
And the US space agency released a recording of one of the Martian meteorite collisions, with a distinctive “bloop” sound, three times as the space rocks entered the atmosphere. , explodes into pieces and collides with the surface.
Impacts ranged from 53 to 180 miles (85 to 290 kilometers) away from the probe's fixed location in a region of Mars called Elysium Planitia, a smooth plain north of the planet's equator.
The first of the four meteorites - the term used for space rocks before they reached the surface - were the most dramatic. It entered the atmosphere of the red planet on September 5, 2021 and exploded into three fragments, each leaving a crater behind.
Then NASA's Mars Reconnaissance Orbiter flew over the estimated impact site to confirm the location.
A black and white context camera was used to reveal three dark spots on the surface.
After locating these spots, the orbiter team used the High Resolution Imaging Science Experiment (HiRISE) camera to obtain a color close-up of the craters.
"After three years of waiting for Insight to discover the impact, these craters looked beautiful," said Ingrid Dubar of Brown University, co-author of a new paper on the discovery specializing in Mars impacts.
After combing through past data, scientists confirmed three more impacts on May 27, 2020, February 18, 2021 and August 31, 2021.
Scientists revealed their confusion about why they did not discover more impacts of meteorites on Mars, as the red planet is located next to the main asteroid belt of the solar system, which provides an abundant supply of space rocks to sabotage the planet's surface.
Because Mars' atmosphere is only 1% as thick as Earth's, more meteorites pass through it without disintegrating.
Insight's seismometer has already detected more than 1,300 earthquakes. The French space agency and the National Center for Space Studies say the device is so sensitive that it can detect seismic waves from thousands of miles away.
But a fifth event, in September 2021, marked the first time that an effect had been confirmed as a cause of such waves.
The Insight team suspects that other effects may be obscured by wind noise or seasonal changes in the atmosphere.
But now that the distinctive seismic signature of impact has been discovered on Mars, scientists expect to find more impacts in the roughly four years of Insight data.
Seismic data provides various clues that will help scientists better understand the Red Planet.
Most earthquakes occur because subsurface rocks are fractured by heat and pressure. Studying how the resulting seismic waves change as they travel through different materials provides scientists with a way to study Mars' crust, mantle, and core.
The four impacts of the meteorites, which have been confirmed so far, have caused small earthquakes of no more than 2.0 magnitudes.
These small earthquakes provide scientists with only a glimpse into Mars' crust, while seismic signals from larger earthquakes, such as the magnitude 5 event in May 2022, can also reveal details about the planet's atmosphere and core. But the effects will be crucial to improving the timeline of Mars.
Source: websites