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

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

The Andromeda galaxy is over 2 million light-years away from us.

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

A black hole in the center of the M87 galaxy in the constellation Virgo, which is 50 million light-years away, has been calculated to have a mass equal to that of 3 billion Suns!

Out of all the exoplanets found by Kepler, this distant world – located 300 light-years from Earth – is most similar to Earth in size and estimated temperature.

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

The planet Sakura is 4.7 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.

The nearest star is about four and half light-years away from the earth.