The Carina nebula by ESO | CC BY
The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is a group that “builds and operates a suite of the world’s most advanced ground-based astronomical telescopes.” With those telescopes they produce some absolutely amazing photographs and videos, all of which are released under a CC BY license. Check out their visual of the week for some particularly stunning photographs.
Eso on Wikipedia :
http://en.wikipedia.org/wiki/European_Southern_Observatory
Computerhotline, good point. And Wikimedia Commons is another way to view many of the ESO images — http://commons.wikimedia.org/wiki/Category:European_Southern_Observatory_Images
Note that the liberal CC BY license permitted Wikimedia Commons to use the ESO images, and note Wikimedia Commons’ very careful copyright/license notice/explanation.
Mike : Of course.