These insights into Earth’s past came out of a new study that details how they found the likely Martian origin of the 4.48-billion-year-old meteorite, informally nicknamed Black Beauty. Its origin is one of the oldest regions of Mars. The study was published on July 12 in the journal
“This meteorite recorded the first stage of the evolution of Mars and, by extension, of all terrestrial planets, including the Earth,” said Valerie Payré, a postdoctoral researcher in the Department of Astronomy and Planetary Science. “As the Earth lost its old surface mainly due to plate tectonics, observing such settings in extremely ancient terrains on Mars is a rare window into the ancient Earth surface that we lost a long time ago.”
What Mars can tell us about Earth
The research team, led by Anthony Lagain from Curtin University in Australia, searched for the location of origin of a Martian meteorite (officially named NWA—Northwest Africa—7034 for where it was found on Earth). This meteorite, the chemistry of which indicates that Mars had volcanic activity to that found on Earth, recorded the first stage of Mars’ evolution. Although it was ejected from the surface of Mars five to 10 million years after an asteroid impact ago, its source region and geological context remained a mystery.
To pinpoint where Black Beauty came from, this research team studied its chemical and physical properties. They determined it S originated from Terra Cimmeria-irenum, one of the most ancient regions of Mars. It may have a similar surface to Earth’s continents. Planetary bodies like Mars have impact craters all over their surface, so finding the right one is challenging. In a previous study, Lagain’s team developed a crater detection algorithm that uses high-resolution images of the surface of Mars to identify small impact craters, finding about 90 million as small as 50 meters in diameter. In this study, they were able to isolate the most plausible ejection site—the Karratha crater that excavated ejecta from an older crater named Khujirt.
“For the first time, we know the geological context of the only brecciated Martian sample available on Earth, 10 years before the
Payré studies the nature and formation of Mars’ crust to determine if Earth and Mars share a common past that includes both a continent-like and ocean-like crust. She uses orbital observations captured in this region to investigate whether traces of volcanism similar to Iceland exist on Mars.
“As of today, Mars’ crust complexity is not understood, and knowing about the origin of these amazing ancient fragments could lead future rover and spatial missions to explore the Terra Sirenum-Cimmeria region that hides the truth of Mars’ evolution, and perhaps the Earth’s,” she said. “This work paves the road to locate the ejection site of other Martian meteorites that will provide the most exhaustive view of the geological history of Mars and will answer one of the most intriguing questions: why Mars, now dry and cold, evolved so differently from Earth, a flourishing planet for life?”
The research team’s algorithm is adapted to detect impact craters constellating Mercury and the Moon, the other terrestrial bodies. This can be used to help unravel their geographical history and answer foundational questions regarding their formation and evolution. This work is a starting point to guide future investigations of the Solar System.
Reference: “Early crustal processes revealed by the ejection site of the oldest martian meteorite” by A. Lagain, S. Bouley, B. Zanda, K. Miljković, A. Rajšić, D. Baratoux, V. Payré, LS Doucet, NE Timms, R. Hewins, GK Benedix, V. Malarewic, K. Servis and PA Bland, 12 July 2022, Nature Communications.