4 Things Armstrong and Aldrin Left Behind

When Neil Armstrong and Buzz Aldrin departed the moon, they left more than 100 things behind. In honor of the 50th anniversary of the Apollo 11 lunar landing this weekend, Florida Today has a list of seven of the most interesting. A sampling:

• Tributes: A patch from the Apollo 1 mission, commemorating the three astronauts who died when a fire broke out in the command module during a training exercise, was left on the moon as well as medals honoring the fallen Russian cosmonauts Vladimir Komarov and Yuri Gagarin.

• Messages: Leaders from 73 countries offered up messages of hope, goodwill, and peace, which were inscribed microscopically around the edge of a silicon disc the size of a half-dollar coin. The disc reads "From Planet Earth, July 1969," in the center. As PBS reports, Armstrong and Aldrin almost forgot to leave it behind, and did so at the last minute, throwing it from the ladder as they were climbing into their spacecraft.
• Experiments: The Early Apollo Scientific Experiment Package, a collection of science experiments including one that monitored the effects of lunar dust on equipment, was left behind. Just one experiment from Apollo 11 is still active; it involves special mirrors used to help measure the distance between the Earth and the moon and track the moon's orbit.
• Human waste: Along with other trash and gear that was left behind due to the landing module's weight limitations, the astronauts left behind their waste bags. An estimated 96 bags of human waste have been left on the moon by the six Apollo missions.

Click for the full list, or you can check out NASA's catalog of human-made items left on the moon here. (More Apollo 11 stories.)