(also written light minute
) is a unit of length
. It is defined as the distance light
travels in an absolute vacuum
in one minute
or 17,987,547,480 metres
). Note that this value is exact, since the metre is actually defined in terms of the light-second
To give an example, the average distance from the Earth to the Sun (or 1 astronomical unit) is about 8.317 light-minutes.