Light Year is unit for all astronomic distances
The distance to measure star from the Earth is done by Light Years.
AU is not used to measure the distances on earth, because a astronomical unit is a unit of measurement equal to the distance between Earth and Sun. So that's why you cannot use Au for measure the distances on Earth.
An Astronomical Unit is the distance between Earth and the Sun and is used as a measurement unit for measuring the distances of other objects from Earth.
We measure distances between celestial objects (such as suns, planets, and galaxies) by a unit of measurement called "AU" which stands for, Astronomical Unit. One AU is the equivalent to 93 million miles, which is roughly the distance from earth to the sun. Let's compare that to the next closest star to us, Alpha Centauri, which is 4.4 light years away, or about 271,930 AUs! Distances are Immense.
I have usually seen them quoted in kilometers.
A light year is the distance light travels in a year. That is roughly 6,000,000,000,000 miles (six trillion miles). Thus such a unit is used only to measure the largest distances, those between stars and galaxies.
AU is not used to measure the distances on earth, because a astronomical unit is a unit of measurement equal to the distance between Earth and Sun. So that's why you cannot use Au for measure the distances on Earth.
An Astronomical Unit is the distance between Earth and the Sun and is used as a measurement unit for measuring the distances of other objects from Earth.
Kilometers
au
We measure distances between celestial objects (such as suns, planets, and galaxies) by a unit of measurement called "AU" which stands for, Astronomical Unit. One AU is the equivalent to 93 million miles, which is roughly the distance from earth to the sun. Let's compare that to the next closest star to us, Alpha Centauri, which is 4.4 light years away, or about 271,930 AUs! Distances are Immense.
Light years or parsecs
another unit for measuring distances is AU (Astronmical Unit)
To measure the distance of stars you have to measure by light years.
Because it is a large number, suitable for large distances. Astronomers also like to use the unit Parsec.
a Lightyear, around 1013 kilometres.
The unit of measurement that would be best for measuring the distance from the North Pole to the equator is kilometers (km) or nautical miles (nmi). These units are commonly used to measure long distances and are suitable for measuring the Earth's surface.
Use "Astronomical UNit" or AU when discussing distances within the solar system. Use "light year" when talking about the distances between stars.