The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2]
It is a work by NASA. Originally uploaded to en.wikipedia by en:User:Serendipodous. For more informations, see the [http://en.wikipedia.org/key/Image:Eris_and_dysnomia2.jpg description page]. ([http://www.nasa.gov/mission_pages/hubble/news/eris.htm