(ORDO NEWS) — An international team of researchers has found signs of a relatively recent flow of liquid water in meteorites that have been falling to Earth in recent times. In their scientific work, the group describes the study of meteorites of the class of carbonaceous chondrites that have fallen to the surface of our planet over the past century, and the associated findings.
Many scientists believe that water was brought to the early Earth with meteorites. This hypothesis is difficult to test because the meteorites discovered so far do not contain water, and because chemical reactions that may have included cometary water took place millions of years ago. In this new work, researchers led by Simon Turner of Macquarie University, Australia, looked at the problem from a different angle – they studied the isotopes in the material of meteorites that have fallen to Earth over the past one century.
Previous studies have shown that many, if not all, meteorites of the carbonaceous chondrite class formed about 4.5 billion years ago and are fragments of larger parent asteroids. To study the history of water movement in “newly arrived” meteorites, Turner and his group decided to pay attention to the distribution of uranium and thorium in samples – while the compounds of the first of these elements present in meteorites are water-soluble, the compounds of the second practically do not dissolve in water. Based on logic, the analysis of the distribution of the isotopes of uranium and thorium makes it possible to track the movement in the meteorite matter of water formed as a result of the melting of ice – if any. In addition, both isotopes have short half-lives, which means
After studying 9 different meteorites, Turner and colleagues found the changes they predicted in the distribution of uranium and thorium. According to the conclusions made by the authors, this indicates the movement of liquid water in meteorites, which occurred no later than about 1 million years ago. Therefore, the finds indicate that meteorites could deliver water to the Earth not only during the period of its formation, but even in the relatively recent past, the work notes.
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