Earth

Earth (or the Earth) is the third planet from the Sun, and the densest and fifth-largest of the planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is the home planet of us humans.

History
Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. Earth was initially molten due to extreme volcanism and frequent collisions with other bodies.

Estimates of the age of the Moon range from 4.5 Ga to significantly younger. A leading hypothesis is that it was formed by accretion from material loosed from Earth after a Mars-sized object with about 10% of Earth's mass, named Theia, collided with Earth. It hit Earth with a glancing blow and some of its mass merged with Earth. Between approximately 4.1 and 3.8 Ga, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon and, by inference, to that of Earth.