-- Here is part of the one Apollo experiment still functioning--the array of 100 corner mirrors that Apollo 11 astronauts placed on the moon in July of 1969 to reflect laser pulses from Earth back to Earth. -- Monitoring these pulses makes possible the precise measurement of the distance to the Moon, as described in What Neil and Buzz Left on the Moon. -- To learn more about these corner mirrors, see the Lunar and Planetary Institute's Laser Ranging Reflector and, from the University of California, San Diego, Lunar Reflectors.
