NASA Earth Observatory images by Jesse Allen and Josh Stevens, using Landsat data from the U.S. Geological Survey. Caption by Adam Voiland, with information and fact checking by Anja Schmidt (University of Leeds) and John Stevenson (The University of Edinburgh).
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]