Light years - the distance that light would travel in a year, which is approx 9.5 trillion kilometres.
lightyears
The unit of measurement used to measure distances between galaxies is typically the light-year, which is the distance that light travels in one year. This unit is used because of the vast distances involved in intergalactic space.
there are millions of stars in the galaxy
Allan Sandage has written: 'The age of the galactic disk' -- subject(s): Age, Galaxies, Stars 'Hubble Atlas of Galaxies (Carnegie Institution of Washington. Publication)' 'Atlas of galaxies' -- subject(s): Atlases, Cosmological distances, Galaxies, Hubble Space Telescope (Spacecraft), Measurement 'The red-shift' -- subject(s): Spectrum analysis, Nebular hypothesis
They do not use units: they use the fact that stars are not galaxies. For example, you don't use units to measure the difference between children and countries.
Edwin Hubble was famous for measuring the red shift of distant galaxies and interpreting that as evidence of the expansion of the Universe.
We are part of the Local Group. The Local Group contains the Milky Way, two other major galaxies, and dozens of dwarf galaxies. The Local Groups is a group of galaxies which, as galaxies go, are close to us.
Light-years
It shows us the stars and galaxies.
The measurement of my Dad is 6 foot.
they usually use super computers
Imperial measurement is in general use. Engineers, scientists etc use the SI system.