Theia (hypothetical planet)
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Theia is a hypothetical ancient planet in the early Solar System which, according to the giant-impact hypothesis, collided with the proto-Earth around 4.50 billion years ago, with some of the resultin
Artist's depiction of a collision between two planetary bodies, similar to the hypothesized collision between Theia and the proto-Earth.
Full Moon 2010
Giant-impact hypothesis
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The giant-impact hypothesis, sometimes called the Theia Impact, is an astrogeology hypothesis for the formation of the Moon first proposed in 1946 by Canadian geologist Reginald Daly. The hypothesis s
Theia (hypothetical planet)
…Theia ( THEE-uh) is a hypothetical ancient planet in the early Solar System which, according to the giant-impact hypothesis, collided with the proto-Earth around 4.50 billion years ago, with some of the resulting ejected debris re-coalescing to form the Moon. Collision…
Ancient rift valleys – context
Ancient rift valleys – closeup (artist's concept)