If you're asking about the astronomical unit used for measurement, Kiloparsecs are usually used

If you're asking about the astronomical unit used for measurement, Kiloparsecs are usually used.

The term parsec is derived from PARallax and arcSECond. A parsec is the distance at which one astronomical unit(distance from earth to sun) subtends an angle of one arcsecond. An arcsecond is ##1/60## of a degree, or ##1/(21,600)## of a circle.

Essentially, it is the distance at which the movement of the distance of to the earth is perceived as a shift only ##1/60## of a degree across the sky. To put this into perspective, one parsec is 3.26 light years, 31 trillion kilometers, or 19 trillion miles. A kiloparsec is simply 1,000 parsecs.

Another thing used is a light year. It's the distance light travels in 1 year. And that's a lot. ! light year is just under 9,500,000,000,000 kilometers.