ly
What is a Light Year?
Length Unit
Definition
A light-year is the distance that light travels in one year in a vacuum, equal to approximately 9.461 trillion kilometers or 5.879 trillion miles.
Popular Light Year Conversions
Most common conversions from Light Years
1 ly = 9,460,730,472,580,800 m Light Year to Meters 1 ly = 9,460,730,472,580.8 km Light Year to Kilometers 1 ly = 946,073,047,258,080,000 cm Light Year to Centimeters 1 ly = 9,460,730,472,580,800,512 mm Light Year to Millimeters 1 ly = 5,878,625,373,183.61 mi Light Year to Miles 1 ly = 10,346,380,656,803,150 yd Light Year to Yards
History
The term 'light-year' was first used by German astronomer Friedrich Bessel in 1838 when he measured the distance to the star 61 Cygni.
Common Uses
- Measuring distances between stars
- Describing galaxy sizes
- Astronomical research
- Science education
Fun Facts
The nearest star (Proxima Centauri) is about 4.24 light-years away
The Milky Way galaxy is about 100,000 light-years across
Light from the Sun takes about 8 minutes to reach Earth
All Light Year Conversions
Light Years to Meters ly → m Light Years to Kilometers ly → km Light Years to Centimeters ly → cm Light Years to Millimeters ly → mm Light Years to Miles ly → mi Light Years to Yards ly → yd Light Years to Feet ly → ft Light Years to Inches ly → in Light Years to Nautical Miles ly → nmi Light Years to Micrometers ly → μm Light Years to Nanometers ly → nm