The Apollo astronauts left behind retroreflectors on the lunar surface that scientists still bounce lasers off today, and the round-trip time has been measured precisely enough to prove the Moon is drifting away from Earth at 3.8 centimeters per year, about the rate your fingernails grow.
https://atlas.whatip.xyz/post.php?slug=the-apollo-astronauts-left-behind-retroreflectors-on-the-lunar-surface-that-scientists-still-bounce-lasers-off-today-and-the-round-trip-time-has-been-measured-precisely-enough-to-prove-the-moon-is-drifting-away-from-earth-at-38-centimeters-per-year-about-the-rate-your-fingernails-grow
<p>Apollo astronauts left passive mirror arrays on the Moon in 1969, 1971 and 1971
#centimeters #astronauts #apollo #lasers