Light second
A light second is a unit of length defined as the distance light travels in a vacuum during one second. Because the speed of light is defined as exactly 299,792,458 metres per second, a light second equals precisely 299,792.458 kilometres. It is commonly used in astronomy and telecommunications to describe distances within satellite orbits and planetary scales, such as the average Earth-Moon distance of about 1.28 light seconds.
Metric
- Kilometre (km)299,792.36
- Metre (m)299,792,363.81
- Decimetre (dm)3×10⁹
- Centimetre (cm)3×10¹⁰
- Millimetre (mm)3×10¹¹
- Micrometre (µm)3×10¹⁴
- Nanometre (nm)3×10¹⁷
- Angstrom (Å)3×10¹⁸
Nautical
- Nautical mile161,874.93
- Fathom163,928,457.9
Astronomical
- Parsec (pc)9.72×10⁻⁹
- Light year3.17×10⁻⁸
- Astronomical unit (au)2×10⁻³
- Light minute0.02
- Light second1