Mars’ oldest meteorite traced to strange double impact crater
Researchers have used artificial intelligence (AI) to trace the oldest known Martian meteorite to its precise place of origin, and the results could help uncover conditions on our planet solar system‘s planets were as they were in their very first days.
The 11-ounce (320-gram) meteorite, officially named Northwest Africa 7034 but commonly known as the “Black Beauty,” is believed to have impacted Earth about 5 million years ago. After being found in the Sahara desert in 2011, its age has been dated at almost 4.5 billion years – making it the oldest Martian meteorite ever found on Earth.
Scientists believed the meteorite was hurled to Earth after a powerful asteroid impact struck Mars, ripping open portions of the planet’s crust and hurling it into space. Now, using a machine learning algorithm to identify and catalog 94 million craters on Mars, researchers have traced Black Beauty’s origin to a small crater within a crater on Mars’ southern hemisphere. The scientists named the crater Karratha after the Australian mining town where many of the oldest rocks on earth were found. They published their findings in the journal on July 12 nature communication (opens in new tab).
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“Finding the region where the ‘Black Beauty’ meteorite originated is crucial because it contains the oldest fragments of Mars ever found, which are 4.48 billion years old, and similarities between the very old Martian crust, which is around 4.53 billion years old and present continents”, lead author Anthony Lagain, a planetary scientist at Curtin University in Perth, Australia, said in a statement. “The region we are identifying as the source of this unique Martian meteorite sample represents a true window into the earliest environment of the planets, including Earth, which our planet has lost as a result plate tectonics and erosion.”
To identify the meteorite’s origin, the researchers fed images of 94 million Martian craters captured by the Mars Reconnaissance Orbiter’s context camera into a machine-learning algorithm. The AI compared the size and distribution of the craters to the material properties of the scattering meteorite – which has some of the highest potassium and thorium concentrations of any Martian meteorite found on Earth and is one of the most strongly magnetized. This narrowed the list of possible craters to 19, one of which caught the team’s eye because it closely matched the Martian impact chronology and meteorite properties.
By examining the impact crater, scientists found that Black Beauty was sent to Earth thanks to two asteroid impacts. The first – which slammed into Mars about 1.5 billion years ago and formed the 40-kilometer-wide Khujirt Crater – violently ripped Black Beauty and other rocks out of the Martian crust and sent them up into the atmosphere before they reappear rained down on the surface of the red planet. Then, after a 5 to 10 million year hiatus, a second impact sent Black Beauty through space toward Earth, leaving behind Karratha Crater inside Khujirt Crater.
The results suggest that the rocks were once part of Mars’ primordial crust — the red planet’s original crust that formed shortly after its magma ocean cooled and solidified. When plate tectonics destroyed the earth’s primordial crust and the original crust of the moon Buried under thousands of feet of lunar dust, the crater is particularly exciting for scientists wanting to study how the bodies of our solar system formed.
Not only was the algorithm able to pinpoint the ejection sites of other Martian meteorites, the researchers say they plan to adapt their algorithm to conduct similar searches across the moon mercury.
“This will help unravel their geological history and answer burning questions that will help future studies of the solar system, such as the Artemis program to send humans to the moon by the end of the decade, or the BepiColombo mission, going into orbit around Mercury in 2025,” said co-author Gretchen Benedix, a planetary scientist at Curtin University, in the statement.
Originally published on Live Science.
Mars’ oldest meteorite traced to strange double impact crater Source link Mars’ oldest meteorite traced to strange double impact crater
