Scientists may have found a truly strange space rock. This stone, which looks like a meteorite, has a composition very close to the rocks formed in the depths of the ocean. So they think the rock broke off from Earth, flew through space for maybe thousands of years, and then came back to Earth.
Meteorite was found in the Maghreb and purchased in Morocco in 2018. The meteorite was named “Northwest Africa 13188” and weighs 646 grams. Its chemical composition is dominated by two minerals, plagioclase and pyroxene, which make up about three-quarters of the meteorite. On top of that, the team looked at the rock’s isotopic composition, specifically oxygen.
The chemical properties of elements are defined by the number of protons in their nuclei and, as a result, the number of electrons in the orbital of the nucleus in question. However, they can also exist in lighter or heavier variants depending on the number of neutrons present in the nucleus.
Oxygen is no exception. Nearly all oxygen is O-16 (having eight protons and eight neutrons), but there is a small proportion of O-17 and O-18 in nature. Because different celestial bodies have different proportions of these, scientists can use it like a fingerprint to track where an object came from. Minerals and isotopic composition indicate that this rock belongs to Earth.
But that’s not the whole picture. The rock has a well-developed fusion crust, typical of meteorites. It seems hard, if not impossible, to fake it. But what makes it really important as a meteorite is the density of isotopes of beryllium, helium, and neon, which is consistent with a rock that has been exposed to cosmic rays for 10,000 years.
For now, researchers are doing more detailed isotope analysis to better understand what happened to it and how it left Earth in the first place. By the way, it should be noted that the rock is called “boomerang meteor”, although it is not official.
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