Draft story
Apollo 11 laser reflector
A panel on the Moon that sends laser light back to Earth.
The Apollo 11 astronauts set me down on the Moon in 1969. I’m a panel covered in tiny glass prisms. When a laser pulse from Earth hits me, some of that light heads back the way it came.
A telescope on Earth looks for that faint return. Scientists time the round trip. Since they know how fast light travels, they can work out the distance between Earth and the Moon.
After many measurements, they saw a pattern. The Moon is slowly moving away from Earth, by about 3.8 centimeters each year.
What I did
Reflected short pulses of light back toward telescopes on Earth.
What we learned
Timing those pulses helped reveal that the Moon moves about 3.8 centimeters farther from Earth each year.
A detail to remember
My 100 glass prisms can reflect light without any electricity.