Editing Giant-impact hypothesis (section)

=={{anchor|Theia}}Theia==
{{main|Theia (planet)}}
The name of the hypothesised [[protoplanet]] is derived from the mythical [[Greek mythology|Greek]] [[Titan (mythology)|titan]] [[Theia]] {{IPAc-en|ˈ|θ|iː|ə}}, who gave birth to the Moon goddess [[Selene]]. This designation was proposed initially by the English geochemist [[Alexander Halliday|Alex N. Halliday]] in 2000 and has become accepted in the scientific community.<ref name="eapsl176" /><ref name="jrasc97_6_299" /> According to modern theories of planet formation, Theia was part of a population of Mars-sized bodies that existed in the Solar System 4.5 billion years ago. One of the attractive features of the giant-impact hypothesis is that the formation of the Moon and Earth align; during the course of its formation, Earth is thought to have experienced dozens of collisions with planet-sized bodies. The Moon-forming collision would have been only one such "giant impact" but certainly the last significant impactor event. The [[Late Heavy Bombardment]] by much smaller asteroids may have occurred later{{snd}}approximately 3.9 billion years ago.