Space
The Moon is drifting away from Earth by about 3.8 centimeters a year. We know because scientists bounce lasers off mirrors that Apollo 11 astronauts left there in 1969.
ILLUSTRATION · AIThe Moon is receding from Earth at about 3.8 centimeters a year, a rate measured by bouncing lasers off reflectors that Apollo 11 left on the Moon in 1969.
The Apollo 11 laser reflector is a 46-centimeter square panel holding 100 corner cubes of fused silica. Corner cubes send a beam of light straight back toward its source, so observatories can time a laser pulse's round trip to the Moon and back.
What the lasers found
NASA Goddard reported in 1994 that the measurements show the Moon receding at about 3.8 centimeters per year, and that ocean tides on Earth directly influence the Moon's orbit.
SourcesEvery claim traced
- Tier 2 · Secondary1994
- Tier 2 · Secondary2004
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