linear unit - a unit of measurement of length

light year - the distance that light travels in a vacuum in 1 year; 5.88 trillion miles or 9.46 trillion kilometers

light hour - the distance light travels in a vacuum in one hour; approximately one billion kilometers

light minute - the distance light travels in a vacuum in one minute; approximately 18 million kilometers

light second - the distance light travels in a vacuum in one second; approximately 300,000 kilometers

Astronomical Unit, AU - a unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)

parsec, secpar - a unit of astronomical length based on the distance from Earth at which stellar parallax is 1 second of arc; equivalent to 3.262 light years