The 50th anniversary of Apollo 11's Moon landing is shining a spotlight on one of the experiments still being used today.
Astronauts Neil Armstrong and Buzz Aldrin placed a specialized mirror on the lunar surface which would reflect a laser fired by scientists on Earth in order to measure the distance between the two.
“It took about 160 laser shots before they got the first signal, but 50 years later we're still using the same retroreflector. It should have lasted 10 years, that was the requirement,” says Dr. Todd Jaeger, former NASA employee and now global sales director of commercial optics at Heraeus Conamic in the U.S.
The simple experiment has led to our current GPS system.
“It goes into how the atomic clocks worked on the satellite, what correction had to be put into the algorithm,” says Jaeger. “Otherwise, your GPS was accurate to maybe a foot or less for the commercial systems, and by the end of the day the accuracy is off by five miles.”
Every year the Moon spins itself about 3.8 centimeters away from the Earth.
“It has really helped us to not only understand the physics behind this, but to look at old theories like Einstein's theory of relativity, work on the equation to perfect it down to about a millimeter.”