At the end of an investigation mixing geochemistry, artificial intelligence and Martian cartography, scientists managed to locate on the Red Planet the ejection site of a meteorite found on Earth 5 to 10 million years later, in 2011.
This is a first: scientists have managed to find the precise origin of a meteorite collected on Earth. It is a 320 gram piece of Martian rock known as "Black Beauty" (or NWA 7034), a unique sample comprising the oldest fragments of Mars dated to date (4.48 billion years). It was discovered in 2011 in Morocco, near Bir Anzarane, an oasis in the Western Sahara. Since then, its unique geochemical richness has been studied in order to learn more about the Martian geological history. Discovering where it comes from precisely on the crust of Mars was therefore a major challenge of interest. It has been taken up by an international team that publishes its results in the journal Nature Communications .
Supercomputer and AI to the rescue
To discover its ejection site, the international team led by Curtin University in Australia used an artificial intelligence algorithm and the fastest supercomputer in the southern hemisphere, the Pawsey Supercomputing Centre in Perth, Australia. Two tools that allowed them, in less than 24 hours, to map more than 90 million impact craters on the surface of the Red Planet. Among these, 19 credible candidates have been selected as likely to have ejected a fragment of Martian crust into space, a necessary passage to reach the Earth.
By comparing their geological properties with the geochemical characteristics of the meteorite, the researchers were finally able to locate the precise location from which "Black Beauty" was expelled at the time of impact: the Karratha crater. This crater was named for the eponymous city in Western Australia, where the oldest known terrestrial rocks have been found to date. The Karratha crater is thought to have been formed 5 to 10 million years ago. That's when the Martian rock fragment was expelled into space, towards Earth.
"For the first time, we know the geological context of the only Martian impact breccia sample available on Earth, 10 years before the Mars Sample Return mission of NASA returns the samples taken by the Perseverance rover that is currently exploring the Jezero crater," said in a statement Anthony Lagain, who initiated this investigation in reference to the mission that must deliver Martian samples to Earth in 2033. This discovery should allow us to know more about the geological history of Mars and to guide future missions.