Mean distance of the Earth from the Sun is called the "Astronomical Unit" (1 AU). Astronomical unit is about 149 598 000
kilometers or 92 955 888 miles.
A Greek philosopher Aristarchus (living around 300 BC) made one of the
earliest attemps to estimate the sizes and distances of the Sun and the Moon. He estimated that the Sun was 20 times further away
than the Moon. Today with more precise measurements we know that the real distance of the
Sun is actually about 400 times that of the Moon. The closest star to the Earth (other than the Sun) Proxima Centauri is
about 300,000 times further than the Sun. So distances in the universe are truly huge!