Researchers from Curtin University have discovered the first evidence of high-intensity damage produced by an asteroid impact on a Martian meteorite, results that might help scientists figure out when circumstances on Mars were favorable for life.
The study, which was published in the prestigious journal Science Advances, looked at zircon grains in the Martian meteorite NWA 7034. The meteorite, often known as ‘Black Beauty,’ is a rare piece of the Martian surface. The original 320-gram rock was discovered in northern Africa in 2013 and was initially reported.
The meteorite was characterized as a collection of fragmented rock pieces and minerals, predominantly basalt, that hardened and formed a rock over time by lead author Morgan Cox, a PhD candidate from Curtin’s Space Science and Technology Centre (SSTC) in the School of Earth and Planetary Sciences. Inside the meteorite, a zircon maintains signs of damage that happens only after major meteorite strikes.
“This grain is certainly a one-of-a-kind gift from Mars. No prior evidence of high-pressure shock deformation in Black Beauty minerals has been discovered. This finding of shock damage in a 4.45 billion-year-old Martian zircon adds to the growing body of evidence for dynamic activities that shaped the early Martian surface “Ms. Cox said.
“The sort of stress damage in the Martian zircon includes ‘twinning,’ which has been recorded from all of Earth’s largest impact sites, including the one in Mexico that wiped out the dinosaurs, as well as the Moon, but not before from Mars.”
The presence of zircon grains in the Black Beauty meteorite, according to co-author Dr Aaron Cavosie of Curtin’s SSTC, revealed physical evidence of significant impacts on early Mars and had ramifications for the young planet’s habitability.
“Based on the lack of conclusive shock damage, previous investigations of zircon in Martian meteorites suggested that circumstances conducive for life may have existed about 4.2 billion years ago,” Dr Cavosie stated.
“After this period, Mars was subjected to impact bombardment on a scale that has been known to induce mass extinctions on Earth. The zircon we describe gives evidence of such impacts, implying that the habitability window may have happened later than previously believed, perhaps correlating with evidence for liquid water on Mars 3.9 to 3.7 billion years ago.”
Collaborators from the University of Western Australia and the University of Glasgow were also part of the study team.