I would use meters because well thats the only other choice to choose from!
The parsec is 3.26 light years. Astronomers measure distances to remote galaxies in megaparsecs--millions of parsecs. This is about the longest commonly used length metric.
meters or kilometers.
Distances are measured in metres.
Kilometers
There are MANY units used to measure distances both in Metric and in English types. We use Feet and Yards to measure distances in the US. The academic field often uses metric units like meters and kilometers to measure distances. For larger or massive distances there are the units of miles (English) and Kilomiters (Metric) and then in space we have the Astonomical Unit (Distance from earth to Sun) and the Light Year for the biggest distances. And there are the smaller measures of inches and millimeters.
kilometers
You measure long distances with miles.
You measure long distances with miles.
It depends on what you are trying to measure. Long distances usually are measured in miles. Survey distances usually are measured in feet.
For long distances, kilometers are used. A kilometer is about 0.6 miles.
kilometers :D viva mexico!!
You don't, miles are not a unit in the metric system. All distances are measured in metres. Prefixes are used for multiples or fractions of a metre. Distances that used to be measured in miles would, today, be measured in kilometres.