Trappist-1 is located just 39 light-years away from Earth.

The parsec is equal to about 3.3 light-years.

The size of a galaxy may be as little as a thousand light-years across or as much as a million light-years across.

Typically, a space station serviced a locale at least several light-years radially.

The spiral galaxy NGC 3344 is located about 20 million light-years away.

The researchers caution, however that communication with these alien civilizations could be difficult, as the average distance to them would be about 17,000 light-years.

A light-year is a unit of distance. It is the distance that light can travel in one year.

Our solar system is 26,000 light-years from the center of the Galaxy.

A light-year is the distance light travels in one year. It's 9.5 trillion (9,500,000,000,000) kilometers.

Sirius is a binary star system and is about 8.6 light-years distant from our sun.