Astronaut Buzz Aldrin walks on the moon during the Apollo 11 mission in 1969. The landing site at Tranquility Base has remained mostly untouched — though that could change as more nations and even commercial companies start to explore the moon.

Astronaut Buzz Aldrin walks on the moon during the Apollo 11 mission in 1969. The landing site at Tranquility Base has remained mostly untouched — though that could change as more nations and even commercial companies start to explore the mo