Measuring Distances in Space

The distance between the Earth and the Sun is approximately 150 million kilometers, or one astronomical unit (AU). Scientists use astronomical units to measure and describe distances in space. Another measurement is called a light-minute, which is the distance light travels in one minute, or approximately 18 million kilometers.

The dimensions of our solar system are vast. The four inner planets are much closer to the Sun than the four outer planets. There are numerous orbiting comets found beyond the planets in the outer solar system.