Bloop. That’s the sound a rock makes when it slams into Mars. At least, that’s what NASA’s InSight instrument picked up last September when it captured the faint — and, frankly, hilarious — sound of a meteoroid crashing into the Martian atmosphere, exploding into multiple pieces, and hitting the surface hard enough to leave a mark.
Bloop, bloop, bloop. But don’t take my word for it. Listen for yourself.
The noise sounds so funny in part because of how the soundwaves from the impact moved through the dry atmosphere of Mars. In certain conditions, like deserts on Earth, lower-pitched sounds move faster than high-pitched ones. “An observer close to the impact would hear a ‘bang,’ while someone many miles away would hear the bass sounds first, creating a ‘bloop,’” a NASA blog post explains.
The sounds were ultimately detected by InSight, NASA’s lander that landed in 2018 and has recorded ‘“marsquakes” big and small on the red planet over the past few years. Listening in to the shaking of the planet gives scientists a better idea of what’s going on deep under the Martian surface.
It can also give them a glimpse of what’s going on in the planet’s immediate neighborhood, as the meteoroid research shows. (It’s a meteoroid before it hits the ground, a meteorite after.) Sounds from the rock hitting the atmosphere, exploding, and hitting the ground all shook the ground just enough to be picked up by InSight’s instruments.
Researchers had been keeping an ear out for impacts from space rocks for a while in the InSight data, but September 5th, 2021, was the first time they noticed an impact using the instrument. With the information from InSight, scientists were able to pinpoint where they thought the rocks had crashed into the ground. When they sent a Mars Orbiter to check out the possible landing site, they found three craters.
“After three years of InSight waiting to detect an impact, those craters looked beautiful,” said Ingrid Daubar of Brown University in a NASA press release. Daubar is a co-author of a Nature Geoscience paper that was published on Monday detailing the results. Using the information from that impact, they were able to go back through InSight’s data and pick out three more impacts scattered amidst the 1,300 or so marsquakes already detected by the instrument.