(ORDO NEWS) — Millions of years ago, an epic journey began from Mars. A giant asteroid crashed into the surface, ripping out pieces of the Martian crust and throwing them into space.
In 2011, one of these pieces of rock was recovered from the Sahara Desert. The trajectory of his flight accidentally brought him to Earth (or Mars deliberately began to throw stones at us).
Nicknamed the Black Beauty for its gorgeous dark glossy hue, the meteorite, cataloged NWA 7034, is believed to be the oldest piece of Mars we have. And now it has been tracked to the exact impact site of the asteroid that launched it.
The team named this impact crater Karratha, after a region in Australia where some of Earth’s oldest rocks can be found. This new geological context for rock – a volcanic mineral made up of various rocks (a bit like a fruit pie) in a so-called breccia – will help compare the formation history of Earth and Mars.
“For the first time, we know the geological context of the only Martian breccia sample available on Earth,” said planetary scientist Anthony Lagine of Curtin University in Australia, who led the international team of researchers.
“Finding the region of origin of the Black Beauty meteorite is very important because it contains the oldest Martian fragments ever found, 4.48 billion years old, and shows similarities between the very old Martian crust of about 4.53 billion years old and modern terrestrial.
The region we have identified as the source of this unique Martian meteorite specimen represents a veritable window into the earliest environment of planets, including Earth, which our planet lost due to plate tectonics and erosion.”
To date, about 300 meteorites from Mars have ended up on Earth (perhaps Mars took offense at them). Consisting of a 320-gram (11 ounce) piece of rock and a couple of rocks, Black Beauty is absolutely one of a kind: in addition to being the oldest piece of Mars we have, it is the only piece of volcanic breccia among them all.
This is believed to be a record of early conditions on Mars – but exactly where on Mars remains a mystery. The Red Planet is positively dotted with impact craters, making finding a meteorite in any of them extremely difficult.
To do this, Lagain and his colleagues used the powerful Pawsey supercomputer research center in Western Australia and an algorithm developed at Curtin University specifically for detecting impact craters. Analyzing the size and spatial distribution of the 90 million craters detected by this algorithm has allowed scientists to determine the origin of Black Beauty.
The results of the study showed that several blows occurred during the formation of Black Beauty. The oldest rock fragments were knocked out of the Martian crust about 1.5 billion years ago from a site marked by the Hujirt crater (40 km across (25 miles)) in the southern hemisphere of Mars.
This material fell back to Mars, where it remained until 5 to 10 million years ago, when the impact that created the Karratha crater lifted it up again, sending it into space on its way to Earth.
Curtin’s previous research found impacts in meteorite zircon crystals dating back to 4.45 billion years ago, suggesting a massive impact then as well. While the site of the alleged impact remains unknown, it appears that some Black Beauty material may have been involved in at least three impacts on Mars.
The results obtained suggest that the region from which the rock was originally ejected may be a relic of the primitive Martian crust and, therefore, be of great interest for future exploration of Mars.
In addition, this work can be used to find out the origin of some of the other meteorites that Mars has ejected onto Earth. This may help to reconstruct the chronology of the geological history of Mars in more detail. It could also affect other heavily cratered bodies in the Solar System, such as Mercury and the Moon.
“We … are adapting the algorithm that was used to determine the Black Beauty’s ejection point from Mars to reveal other secrets of the Moon and Mercury,” says astrogeologist Gretchen Benedix of Curtin University.
“This will help unravel their geological history and answer burning questions that will inform future exploration of the solar system, such as the Artemis program, which will send humans to the Moon by the end of the decade, or the BepiColombo mission, which will orbit Mercury in 2025.”
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