What can a Martian meteorite teach us about Earth’s origins?

It may seem odd to compare Iceland and Mars today, but more than 4.5 billion years ago, it’s possible the Red Planet had a crust comparable to modern-day Iceland.

The History of "Black Beauty”

Information hidden in the oldest Martian meteorite fragments found on Earth could provide insight into our planet that was lost over billions of years of geological movement, providing further explanations on why the Earth developed into a planet that sustains a broad diversity of life, while Mars did not.

A new peer-reviewed study, published in Nature Communications by an international team of researchers, led by Anthony Lagain from Curtin University in Australia, details how they found the likely martian origin of a 4.48-billion-year-old meteorite, informally named Black Beauty, originating from one of the oldest regions of Mars.

The team searched for the location of origin of the martian meteorite (officially named NWA—Northwest Africa—7034 for where it was found on Earth).

The chemistry of the meteorite indicates that Mars had volcanic activity similar to that found on Earth, recording the first stage of Mars’ geological evolution.

A "rare window into the ancient Earth”

“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,”  Payré explained.

Although it was ejected from the surface of Mars five to 10 million years ago after an asteroid impact, its source region and geological context has remained a mystery, until now.

“For the first time, we know the geological context of the only brecciated Martian sample available on Earth, 10 years before the NASA’s Mars Sample Return mission is set to send back samples collected by the Perseverance rover currently exploring the Jezero crater,” said Lagain, a research fellow in the School of Earth and Planetary Sciences at Curtin.

“This research paved the way to locate the ejection site of other Martian meteorites, in order to create the most exhaustive view of the Red Planet’s geological history,” he added.

Studying the asteroid

The team studied the chemical and physical properties of Black Beauty to pinpoint where it came from, determining it was from Terra Cimmeria-Sirenum, one of the most ancient regions of Mars.

Planetary bodies like Mars have impacts 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.

Using this technology, they were able to isolate the most plausible ejection site, the Karratha crater that excavated ejecta of an older crater named Khujirt.

“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,” Payré said.

“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."

Valerie Payré

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.

“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?” Payré inquired.