Earth’s early history is marked by massive collisions with other objects, including planetesimals.
One of the defining events in our planet’s history, the formation of the Moon
likely resulted from one of these catastrophic collisions when a Mars-sized protoplanet crashed into Earth.
. That’s the Giant Impact Hypothesis, and it explains how the collision produced a torus
of debris rotating around the Earth that eventually coalesced into our only natural satellite.
New research strengthens the idea that Theia left some of its remains inside Earth.
The Giant Impact that created the Moon occurred in the Hadean eon
The Hadean is the first of Earth’s four eons and spans from the Earth’s formation about 4.5 billion years ago up to
about 4.03 billion years ago when it was succeeded by the Archaean eon.
Earth was a magma ocean for about the first 50 million years.