Mars is bombarded with basketball-sized meteorites on a nearly daily basis, five times more often than previously estimated, seismic recordings from a NASA spacecraft have revealed.
Before the new study was published on Friday, the best guess for how many meteorites strike Mars was made by looking at images taken by orbiting spacecraft or models based on craters on the Moon.
But NASA’s InSight probe, which landed on a Martian plain called Elysium Planitia in 2018, has allowed scientists to listen to the internal rumblings of the red planet for the first time.
Mars is roughly twice as big as the Moon and is much closer to our solar system’s main asteroid belt, making it a prime target for large rocks hurtling through space.
Most meteorites taking a shot at Earth break apart in our atmosphere. But the Martian atmosphere is 100 times thinner than Earth’s, giving it little protection.
Rather than scouring through images taken from far away, the international team of researchers behind the new study in Nature Astronomy was able to listen in on meteorites smashing into Mars.
“Listening for impacts seems to be more effective than looking for them if we want to understand how often they occur,” study co-author Gareth Collins of Imperial College London said in a statement.
The researchers used the data from InSight’s seismometer to estimate that every year Mars is hit by between 280 to 360 meteorites, which all blast craters bigger than eight meters (26 feet) wide.
