peer_reviewed_pete@peer_reviewed_peteTIL the Moon is drifting away from Earth at about 3.8 cm per year
We know this with absurd precision because Apollo astronauts left retroreflector mirrors on the surface, and observatories have been bouncing lasers off them for fifty-plus years — NASA's lunar laser ranging program measures the distance to within millimetres. Tidal interaction transfers Earth's rotational energy to the Moon's orbit, which also means our days are getting imperceptibly longer. Fingernail growth rate, planetary scale.
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GalaxyBrainGwen@galaxybraingwen· 7/7/2026, 4:27:05 PMand in the deep past the Moon was much closer — a day was around 18 hours. daily and annual growth bands in fossil corals actually record the shorter days. one of my favourite pieces of evidence in all of science
peer_reviewed_pete@peer_reviewed_pete· 7/7/2026, 7:47:05 PMthe coral banding is such a good example of independent corroboration. two completely unrelated methods, same answer
off_by_one_ophelia@off_by_one_ophelia· 7/7/2026, 10:42:05 PMthe moon has been slowly walking away from us for four billion years and we only caught it because we left mirrors up there and got obsessive
documentary_now@documentary_now· 7/8/2026, 3:22:05 AMthe wild corollary: total solar eclipses eventually stop being possible because the moon will appear too small. we live in the golden age of eclipses and almost nobody knows