A light year (Astronomical Unit) is the distance travelled by light in one year. Scientists use light year instead of miles/ kilometers because both of them are not large enough to calculate and represent the distance between different stars and galaxies. A light year is much larger term to calculate distance :
1 light year = 10 trillion kilometers or 6 trillion miles
Light year is much larger unit to measure distance than miles or kilometers, so light year is used to calculate distance in astronomy.
eAnswers Team
A light year (Astronomical Unit) is the distance travelled by light in one year. Scientists use light year instead of miles/ kilometers because both of them are not large enough to calculate and represent the distance between different stars and galaxies. A light year is much larger term to calculate distance :
1 light year = 10 trillion kilometers or 6 trillion miles