Scientists studying Mars on Thursday revealed the remarkable Christmas present they received from the planet last year.
On December 24, 2021, a meteorite struck the surface of Mars, triggering magnitude 4 tremors recorded by NASA’s InSight spacecraft — which landed on the planet four years ago — about 2,200 miles (3,500 kilometers) away.
The true origin of this so-called Marsquake was only confirmed when, less than 24 hours later, the Mars Reconnaissance Orbiter (MRO) was able to capture an image of the newly formed crater created by the impact while flying over the impact site.
The image is stunning, showing blocks of ice being flung onto the planet’s surface around the hole, which is 150 meters wide and 21 meters deep.
The crater is the largest ever observed since MRO began orbiting Mars 16 years ago.
And while meteor impacts are not uncommon on Mars, “we never thought we would see something this big,” Ingrid Daubar, who works on the InSight and MRO missions, told reporters at a news conference Thursday.
Researchers estimate that the meteorite itself would have been 16 to 39 feet in diameter. An object that size would have disintegrated in Earth’s atmosphere before hitting the ground here.
“It’s easily the largest meteorite impact on the ground that we’ve heard since science started using seismographs or seismometers,” said planetology professor Philippe Lognonne, who was involved in two studies related to the observation published in the journal Science Thursday.
NASA released an audio recording of the collision, made by accelerating vibrations collected by the seismometer.
– “Useful” Ice Presence –
The valuable information gathered during the study of the crash will contribute to a deeper understanding of the interior of Mars and the planet’s formation history, scientists said.
The presence of ice in particular is “surprising,” said Daubar, who was also a co-author of the two studies.
“This is the warmest spot on Mars closest to the equator we’ve ever seen water ice,” she said.
In addition to the information this discovery offers about the Martian climate, the presence of water at this latitude — and not just near the poles — could prove “really useful” for future human visitors to Mars, according to director of the Planetary Science Division of the planet NASA, Lori said Glaze.
“We want to land the astronauts as close to the equator as possible,” she said, to take advantage of the warmer temperatures.
“This ice could be converted into water, oxygen, or hydrogen,” Glaze said.
The impact was strong enough to generate seismic waves both down to the planet’s core and horizontally across its crust, making it possible to study the internal structure of Mars – revealing that the crust on which InSight sits is less dense is as the crust over which the waves have traveled from the crater site.
According to Bruce Banerdt of NASA’s Jet Propulsion Lab, the end of InSight’s mission – which recorded a total of more than 1,300 marsquakes – could come in the next few months due to expected dust buildup on the lander’s solar panel.
It was “sad,” he said, while celebrating the probe’s four years of “working beautifully”.
