Bewitching, beguiling, and bewildering, Earth’s Moon gleams like a light-reflecting mirror as it glistens high above us–the largest object in our sky on clear dark nights. Even though our Moon is Earth’s closest companion in space–and the only world beyond Earth that we have walked upon–it still has managed to keep many of its secrets to itself. How was our Moon born, and where did it come from? Although the prevailing theory, known as the Giant Impact Model remains the favored scientific scenario of lunar origin, there are other possibilities that can also explain ancient Moon-birth. In February 2018, planetary scientists offered a new explanation for the birth of Earth’s Moon, suggesting that it formed inside the Earth when our primordial planet was a spinning, searing-hot cloud, called a synestia. Click the link miner cloud
A synestia is a doughnut-shaped cloud made up of vaporized molten rock. This recently discovered inhabitant of the Cosmos is thought to take shape when planet-sized bodies catastrophically crash into each other with both high energy and angular momentum. Soon after the discovery of these celestial “doughnuts” in 2017, planetary scientists realized that they may have opened up a new window, revealing the previously unknown secret of Moon-birth. The primordial collisions, that produce a synestia, are so violent that the bodies born from these cosmic crashes melt and partially vaporize–finally cooling off and solidifying to form (almost) spherical planets, such as those in our own Solar System.
This new model, developed by planetary scientists at the University of California, Davis and Harvard University in Cambridge, Massachusetts, resolves several mysteries of lunar formation. A paper describing this study has been accepted for publication in the Journal of Geophysical Research–Planets, a publication of the American Geophysical Union (AGU).
“The new work explains features of the Moon that are hard to resolve with current ideas,” commented Dr. Sarah Stewart in a February 28, 2018 AGU Geospace report. Dr. Stewart is a professor of Earth and Planetary Sciences at UC Davis.
“The Moon is chemically almost the same as the Earth, but with some differences. This is the first model that can match the pattern of the Moon’s composition,” she added.