About 4.5 billion years ago, a Mars-sized object, named Theia, slammed into a proto-Earth to create the Moon.
LONDON — A long-lost planet that helped create the Moon may have formed much closer to the Sun than scientists once thought, according to new research. Scientists have discovered that Theia, the ...
The moon is Earth's only natural satellite, a rocky celestial body that orbits our planet at an average distance of about 384 ...