Researchers have suggested that an unusual rock recently discovered in North Africa could be the first known “boomerang meteorite” – a space rock that originates from our planet before being ejected into space and then falling to Earth. However, not everyone agrees with the new findings, which have yet to be reviewed.
The meteoriteNamed NWA 13188 and weighing about 23 ounces (646 grams), it was discovered by meteorite hunters in 2018 in an undisclosed part of the Sahara desert in Morocco. No one saw the rock fall to earth, and its composition was found to be very similar to volcanic rocks.
But a group of researchers who recently analyzed the rock now believe it was a terrestrial meteorite, a rock that originated on Earth and flew into space millions of years ago, only to land on our planet. Jerome Gattake, a meteorologist at the University of Aix-Marseille in France, presented his team’s findings on July 11 at an international geochemistry conference in Lyon, France. (Their work has not yet been published in a peer-reviewed journal.)
If the team is correct, NWA 13188 will be recognized as the first official terrestrial meteorite discovered on Earth.
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Researchers believe NWA 13188 is a meteorite because it has a “well-developed fusion crust” — a thin layer of heat-shocked rock on its surface that is a sign that it was partially burned up in Earth’s atmosphere, not seen in volcanic rocks on Earth.
The team also found traces of isotopes (elements with different numbers of neutrons in their nuclei) including beryllium-3, helium-10 and neon-21, indicating the rock was exposed. Cosmic Rays – High energy particles traveling through space at nearly the speed of light. The levels of these isotopes indicate that the rock has been in space for at least 10,000 years, but possibly longer.
There are two scenarios for how the meteorite was once ejected into space: the first is that a large volcanic eruption launched it directly into space, and the second is that it was ejected from the atmosphere by a giant. Asteroid influence Researchers believe the latter explanation is the most likely, as none of the recorded volcanic eruptions were strong enough to launch rocks into space.
Not everyone is ready to classify the rock as a boomerang meteorite.
“It’s an interesting rock,” Ludovic FerrierThe curator of the meteorite collection at Austria’s Vienna Natural History Museum told sister site LiveScience, which was not involved in the new analysis. Space.com. But it “requires further investigation before making such extraordinary claims.” Without being able to trace it to an impact crater or know how old it is, it’s difficult to determine exactly how the rock left or re-entered the Earth, he added.
Others think the rock may have been born elsewhere solar system Although similar to Earth’s rocks. “I think there’s no doubt it’s a meteorite.” Frank Brenker, a geologist at Goethe University Frankfurt in Germany, who was not involved in the new analysis, told Space.com. “Whether it actually came from Earth is debatable.”
The research team is conducting further analysis to determine the rock’s exact age and look for any other clues that might determine how it was removed from Earth.
NWA 13188 may be the first boomerang meteorite discovered on Earth, but it is not the first terrestrial meteorite discovered. In a 2019 study published in the journal Earth and Planetary Science LettersDuring the 1971 Apollo 14 mission, researchers identified an unusual rock from the moon that contained tiny fragments of quartz, feldspar, and zircon, all of which originated on Earth. They suggest that this chunk of rock was ejected from our planet the moon It was very close to our planet billions of years ago.