Collection: NASA Great Images in Nasa Collection
Title: Buzz Aldrin on the Moon

Collection: NASA Marshall Space Flight Center Collection
Name of Image: Apollo 17 Astronaut Cernan Adjusts U.S. Flag on Lunar Surface

Collection: NASA Great Images in Nasa Collection
Title: Dr. Robert Goddard at Clark University

An awesome resource. Nasa has started a flickr page for all of their photos in the Public domain. The collection provides a “comprehensive online compilation of (the agency’s) vast collection of photographs, historic film and video.”

(Source: itsnicethat.com)