(The Moon is currently about 384,000 km or 60 Earth radii away from Earth, which is about fifteen times further away than it was when it first formed.) The Moon probably couldn't have formed closer than 3 Earth radii because tidal forces from the Earth would just pull it apart again, and it is unlikely that the impact could have ejected material ...
About 78% of Earthâs atmosphere is made up of nitrogen. Credit: NASA We might commonly think of Earth as having an oxygen-dominated atmosphere, but in reality the molecule makes up only a fifth of our air.
Venus has an atmosphere much denser than Earths, while Mars has an extremely thin atmosphere. All the gas giant planets (Jupiter, Saturn, Uranus, Neptune) have significant atmospheres, as their name implies! Even Pluto, which is not officially a planet anymore, has an atmosphere.