|The Big Bang occurred a little less than ____ billion years ago.
|The Moon is about ____ miles from the Earth.
|There are ____ planets in the Solar System.
|The Sun is about ____ times larger than the Earth.
|About ____ planets have been discovered in the Milky Way.
|Mercury and Venus have no moons. Mars has ____ moons.
|Saturn and Jupiter have about ____ moons each.
|Neptune is about ____ astronomical units (AU) from the Sun.