Planet Astronomical Classroom Millions of Millions of
Units* Scale (in cm) Kilometers Miles
Mercury 0.4 4 57.9 36
Venus 0.7 7 108.2 67
Earth 1.0 10 149.6 93
Mars 1.5 15 227.9 142
asteroids** 2.8 28 418.9 257
Jupiter 5.2 52 778.3 485
Saturn 9.5 95 1,427.0 890
Uranus 19.2 192 2,869.6 1780
Neptune 30.1 301 4,496.6 2810
Pluto 39.5 395 5,900 3670
* An astronomical unit (AU) is a distance unit based on the average distance of the Earth from the Sun.
** The asteroid belt is a region between the orbits of Mars and Jupiter in which most of the Solar System's asteroids are located. An asteroid is a small, generally rocky, solid body orbiting the sun and ranging in diameter from a few meters to hundreds of kilometers.