Some scientists predict that meteorites delivered water to Earth from the outer solar system throughout its 4.5 billion-year history, and that meteorites may still be bringing water to Earth today, according to a new research paper published in the journal Science, the academic journal of the American Association for the Advancement of Science.
The likelihood that meteorites brought water to Earth early in its history is not a particularly controversial claim; however, this new research suggests that rather than stopping the delivery of water billions of years ago, meteorites might still be delivering water to Earth now. According to the research paper, the researchers studied carbonaceous chondrites, remnants of the building blocks of the solar system, and found that there has been a continuous flow of liquid through them over the past million years.
It is worth noting that carbonaceous chondrites are ancient parent bodies that orbit in the outer solar system beyond Jupiter’s orbit, which have not undergone any disturbances or significant changes since their formation.
In this context, scientists led by Professor Simon Turner from Macquarie University in Sydney, Australia, examined carbonaceous chondrite meteorites collected from around the world to find signs of recent liquid flow, focusing on uranium and thorium isotopes.
Since uranium is soluble in water, it has a high capacity for transporting liquids, but it decays radiatively into thorium, a stable element, and its radioactive signature should disappear within a million years due to radioactive decay. However, this was not the case for some of the meteorites that scientists examined and studied.
According to the research paper, the scientists concluded that the parent bodies present in the solar system still contain water or methane liquids, suggesting that the reason could be the melting of ice in the parent bodies during the very impacts that lead to the creation of meteorites. This, in turn, indicates that meteorites may have been transporting water to Earth throughout our planet's history.
