This image, originally posted to Flickr, was reviewed on 22:03, 30 April 2014 (UTC) by the administrator or reviewerww2censor, who confirmed that it was available on Flickr under the stated license on that date.
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]