scientist might have found a truly weird tilt . It look like a meteorite , but its composition is very close to that of rocks that form deep in the ocean . And so , they have proposed a extremist account : that this rock was knocked off the Earth , fly through outer space for perchance thousands of years , and then came back to Earth .

The meteorite was recuperate in the Maghreb and purchased in Morocco in 2018 . It has the designationNorthwest Africa 13188and a mass of 646 grams ( 23 ounces ) . Its chemical musical composition is overshadow by two mineral , plagioclase and pyroxene , which make up about three - quarters of the meteorite . On top of that , the team attend at the isotopic composition of the sway , in particular of oxygen .

The chemic properties of elements are fix by the telephone number of protons in their nucleus and , by consequence , the number of electron that orbit said lens nucleus . But they can come in variants that are eitherlighteror heavier , which depends on the number of neutron that are also present in the nucleus .

Oxygenis no exception . Almost all oxygen is O-16 ( which has eight proton and eight neutrons ) , but there is a tiny percentage of O-17 and O-18 in nature . dissimilar celestial physical structure have different fractions of them , so scientists can use this like a fingerprint to track where an objective is from . The minerals and the isotopic theme spot to this rock being very much an Earthly one .

But that is not the full picture . The stone has a well - developed fusion gall . That is typical of meteorites . It would be unmanageable to fake it , though not unsufferable . But what really sells it as ameteoriteis the concentration of isotope of beryllium , helium , and atomic number 10 that are consistent with a rock candy being exposed to cosmic re for 10,000 years .

“ Therefore , we deliberate NWA 13188 to be a meteorite , launch from the Earth and later re - accreted to its surface . This scenario matches the latest definition of meteorite : ‘ Material launched from a celestial body that achieves an independent orbit around the Sun or some other celestial body , and which finally is re - accreted by the original body , should be considered a meteorite . The difficultness , of course of action , would be in essay that this had happened , but a tellurian John Rock that had been exposed to cosmic ray and had a well - developed unification incrustation should be consider a possible planetary meteorite ' , ” the authors wrote in an abstract presenting the breakthrough .

They are now performing further isotopic depth psychology to better understand what happened to it and how it was capable to leave Earth in the first place .

The enquiry was presented at the 2023Goldschmidt Conferenceon geochemistry .