Astronomy Picture of the Day

Explanation: After the most famous voyage of modern times, it was time to go home. After proving that humanity has the ability to go beyond the confines of planet Earth, the first humans to walk on another world -- Neil Armstrong and Buzz Aldrin -- flew the ascent stage of their Lunar Module back to meet Michael Collins in the moon-orbiting Command and Service Module. Pictured above on 1969 July 21, the ascending spaceship was captured by Collins making its approach, with the Moon below, and Earth far in the distance. Tomorrow marks the 40th anniversary of the first human moon landing. Recently, NASA's moon-orbiting Lunar Reconnaissance Orbiter sent back the first pictures of most of the Apollo landing sites -- including Apollo 11 -- with enough resolution to see the Lunar Module descent stages left behind.