You don't really. You can just as well use the SI unit of length - the meter - and express the numbers in scientific notation. But most people prefer the smaller numbers that appear when using light-years or parsecs.
light years
. . they are a convenient unit. Another convenient unit is the parsec.
light years
Yes, astronomers use light-years to measure the distance between stars in space. A light-year is the distance that light travels in one year, which is about 9.46 trillion kilometers or 5.88 trillion miles. This unit of measurement is more practical given the vast distances in space.
Light years or parsecs
light years
Light Years.
Light year or astronomical units
usually the space is measured in light years
you use light years, and other units
To measure the distance of stars you have to measure by light years.
Astronomers use the unit of measure "Light Years" to calculate the distance between pretty much anything in the Universe.
light years
That is correct.That is correct.That is correct.That is correct.
scientists use light-years to measure long distances in space. a light year, (abrviated ly) is the distance light can travel.
. . they are a convenient unit. Another convenient unit is the parsec.
light-years, parsecs, and megaparsecs