The NWA 7034 meteorite, nicknamed Black Beauty, has fascinated geologists since it was discovered in the Sahara Desert in 2011.
Scientists announced Tuesday that they had found the crater from which the oldest known Martian meteorite to Earth was originally launched, a discovery that could provide clues as to how our own planet formed.
The NWA 7034 meteorite, nicknamed Black Beauty, has fascinated geologists since it was discovered in the Sahara Desert in 2011.
It fits easily in the hand, weighing just over 300 grams (10.6 ounces) and contains a mix of materials including zircons, dating back nearly 4.5 billion years.
“This makes it one of the oldest rocks studied in the history of geology,” Sylvain Bouley, a planetary scientist at the University of Paris-Saclay in France, told AFP.
His journey dates back to the childhood of the solar system, “about 80 million years after the planets began to form,” said Bouley, who co-authored a new study of the meteorite.
The distribution of 90 million craters on the surface of Mars obtained from the crater detection algorithm. The colors indicate the size of the crater and its intensities are related to the density of the crater on the surface. Blue spots and ray patterns are associated with younger, larger craters formed on the surface. The red circle points to the Karratha crater that has ejected the Black Beauty meteorite. Credit: Lagain et al, Curtin University
Tectonic plates long ago covered the ancient earth’s crust, meaning “we have lost this primitive history of our planet,” Bouley said.
But Black Beauty could offer “an open book about the first moments of a planet,” he added.
To open this book, a team of researchers from Curtin University in Australia set out to find the original meteorite house on Mars.
They knew it was probably an asteroid that hit the red planet that sent Black Beauty shooting into space.
The impact “was strong enough to eject rocks at a very high speed, more than five kilometers (three miles) per second, to escape Martian gravity,” said Anthony Lagain de Curtin, lead author of the study in Communications of naturehe told AFP.
This crater should be massive, at least three miles in diameter.
The problem? The marked surface of Mars has about 80,000 craters at least as large.
Following the clues
But researchers had a clue: by measuring Black Beauty’s exposure to cosmic rays, they knew she was evicted from her first home about five million years ago.
“So we were looking for a crater that was very young and big,” Lagain said.
Another clue was that its composition showed that it had suddenly warmed up about 1.5 million years ago, probably due to the impact of a second asteroid.
The team then created an algorithm and used a supercomputer to track images of 90 million craters taken by a NASA satellite.
This reduced it to 19 craters, allowing investigators to rule out the remaining suspects.
They discovered that Black Beauty was unearthed from its first home by an asteroid that impacted about 1.5 billion years ago, forming the 40-kilometer Khujirt crater.
Then, a few million years ago, another asteroid struck not far away, creating the 10-kilometer Karratha crater and shooting Black Beauty into Earth.
The southern hemisphere region of Mars is rich in potassium and thorium elements, as is Black Beauty.
Another factor was that Black Beauty is the only highly magnetized Martian meteorite.
“The region where Karratha was found is the most magnetized on Mars,” Lagain said.
Known as the Terra Cimmeria-Sirenum province, it is “a relic of the first crustal processes on Mars and therefore a region of great interest for future missions,” the study said.
Bouley noted a “bias” in the missions currently planned on Mars in favor of the search for signs of water and life.
But to understand how planets form for the first time would answer some fundamental questions, Lagain said, including “how the Earth became such an exceptional planet in the Universe.”
Machine learning identifies the crater that ejected the famous Martian rock. More information: Anthony Lagain, The first processes of the crust revealed by the ejection site of the oldest Martian meteorite, Communications of nature (2022). DOI: 10.1038 / s41467-022-31444-8. www.nature.com/articles/s41467-022-31444-8
© 2022 AFP
Citation: Scientists find the original home of the oldest Martian meteorite (2022, July 16) recovered on July 16, 2022
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