Earth-Life Science Institute, Japan | 2020 Jun 22
The Earth-Moon system’s history remains mysterious. Scientists believe the two formed when a Mars-sized body collided with the proto-Earth. Earth ended up being the larger daughter of this collision and retained enough heat to become tectonically active. The Moon, being smaller, likely cooled down faster and geologically ‘froze’. The apparent early dynamism of the Moon challenges this idea.The composition of the Moon’s near side is oddly different from that of its far
side, and scientists think they finally understand why. Credits: NASA/NOAA
New data suggest this is because radioactive elements were distributed uniquely after the catastrophic Moon-forming collision. Earth’s Moon, together with the Sun, is a dominant object in our sky and offers many observable features which keep scientists busy trying to explain how our planet and the Solar System formed. Most planets in our solar system have satellites. For example, Mars has two moons, Jupiter has 79 and Neptune has 14. Some moons are icy, some are rocky, some are still geologically active and some relatively inactive. How planets got their satellites and why they have the properties they do are questions which could shed light on many aspects of the evolution of the early Solar System.
The Moon is a relatively cold rocky body, with a limited amount of water and little tectonic processing. Scientists presently believe the Earth-Moon system formed when a Mars-sized body dubbed Theia – who in Greek mythology was the mother of Selene, the goddess of the Moon – catastrophically collided with the proto-Earth, causing the components of both bodies to mix. ...
Early Crust Building Enhanced on the Moon’s Near Side
by Mantle Melting-Point Depression ~ Stephen M. Elardo et al
- Nature Geoscience 13(5):339 (May 2020) DOI: 10.1038/s41561-020-0559-4