Curtin University researchers have helped discover the largest fresh meteorite impact craters on Mars since NASA’s Mars Reconnaissance Orbiter began scouring the planet for them 16 years ago.
On December 24, 2021 NASA’s InSight Lander registered a five-magnitude earthquake that was recently discovered to be caused by a meteorite impact. One of the excavated meteorites contained ice at the lowest altitude ever observed on the planet, an important discovery for NASA’s future exploration plans.
The discovery was helped by two scientists from Curtin University, the only two Australians on the NASA-led international research team. The study, titled “The largest recent impact craters on Mars: an orbital imaging and surface seismic joint study“, was published in the magazine Science.
Discovering the craters with NASA technology
The meteorite is believed to have spanned 16-39 feet, making way for the rare discovery of two impact craters, both larger than 130 meters in diameter each. The craters, believed to be among the largest ever to form in the Solar System, were discovered using NASA imaging technology and seismometers. Larger chests exist on Mars, but they precede any mission to the planet.
Study co-author Associate Professor Katarina Milkovic of the Curtin Center for Space Science and Technology and the School of Earth and Planetary Sciences said: “In addition to NASA’s Mars Reconnaissance Orbiter imager, NASA’s InSight seismometers were operating in the second half of 2021. when these impacts are recorded as having occurred.
“They detected these impact events in the form of a large seismic activity or ‘bang’, first when the meteorite passed through the atmosphere and then again when it hit the ground.
“Events happen all the time on both Earth and Mars, but they usually involve small rocks from space just grazing the atmosphere. Sometimes we get shocks that can penetrate deeper into the atmosphere to produce a noticeable explosion in the atmosphere or on the ground, as was the case here.
The importance of studying meteorite impact events
The magnitude of the meteorite impacts, which occurred in a region called Amazonis Planitia, generated the only two earthquakes known to have been caused by it, said study co-author PhD student Andrea Rajsic, who completed the research while at Curtin’s Space Center for Science and technologies.
The Martoquake caused by this impact is the first to have surface waves rippling through the planet’s crust.
“There aren’t that many large earthquakes detected on Mars, whether they’re caused by internal geological forces or in this case external impacts, but when they do occur, they help map the deep interior of Mars,” Raisic said.
“Impact events are extremely useful in seismology because they can be viewed as a confined seismic source with a known location. It’s a fantastic way to peer into the inner structure of the Red Planet.
One of the meteorite impacts unearthed large chunks of ice buried closer to the Martian equator than ever before. These findings will add to our current understanding of Mars’ water reservoir.
Associate Professor Milkovich said: “This knowledge is useful for many reasons, from the potential future habitation of Mars by humans and their ability to find water as a resource, to the fundamental understanding of the structure of Mars as a planet. If we want to understand the formation and evolution of our own planet, we need to understand other terrestrial planets.
Dr Raisic completed his PhD contributing to this work at the Curtin Center for Space Science and Technology. Curtin’s part of this research was funded by the Australian Research Council.
