(NASA/GSFC/Arizona State University)

American flags planted on the moon by Apollo astronauts are still standing, still casting shadows.

NASA sent six crews to land on the moon between 1969 and 1972. New photos from NASA's Lunar Reconnaissance Orbiter show all flags standing except the one posted by Apollo 11. That was not a surprise; astronaut Buzz Aldrin had reported he saw the flag blown over by the exhaust from their ship's engine as they left the lunar surface.

"Personally I was a bit surprised that the flags survived the harsh ultraviolet light and temperatures of the lunar surface, but they did," Mark Robinson, the principal investigator for the Lunar Reconnaissance Orbiter Camera (LROC), said in a blog post. Robinson suggests in his blog that the flags are most likely badly faded.

The images taken by the LROC are the sharpest ever taken in space, according to NASA.

Lunar Reconnaissance Orbiter was launched in June 2009. It circles the moon, often from altitudes of less than 20 miles, exploring the moon's environment to prepare for future expeditions.