These huge groups of stars, gas and dust can be many thousands of light years across.

VOA: special.2009.01.20

"Now,if you're on a star about 1,000 light years away, you see earth as it was 1,000 years ago.

VOA: standard.2010.04.16

"Even an optimist like Frank Drake estimates that there would be no more than about in the galaxy, which means that the nearest one is likely to be about 1,000 light years away."

VOA: standard.2010.04.16

He was born in this very light house eighty three years ago.

VOA: special.2010.05.08