Up until about ten years ago, scientists thought they had a pretty good picture of how the moon and Earth came to co-exist. Then more precise measurements blew it all wide open, and scientists are still struggling to reconcile them.
As part of that effort, a team including UChicago cosmochemist Nicolas Dauphas performed the largest study to date of oxygen isotopes in lunar rocks, and found a small but measurable difference in the makeup of the moon and Earth.
Published March 28 in Science Advances, the research proposes that Earth acquired the majority of its water during the main stage of its growth—which counters a popular theory.
The most widely accepted theory of the origin of the Moon speculates that a giant object smashed into the proto-Earth at just enough velocity that part of both bodies broke off and formed the moon. The Earth has a little of the moon and the moon has more of the Earth, but they’d be mostly different objects. Early measurements—many taken by the late UChicago geochemist Robert Clayton—did not have sufficient precision to tell the Moon and Earth apart.
Read more at University of Chicago
Image: Meteorites such as these carbonaceous chondrites are thought to have delivered water to the Earth--but an outstanding question is when. A new study points to the early incorporation of water in the growing Earth. (Credit: Image courtesy Nicolas Dauphas)