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The Moon's tidal forces on our planet continue to slow Earth's rotation. Every century, the length of our day increases by about one and a half milliseconds. (To keep up, earthlings invented leap seconds, but that's another story for another afternoon.) Meanwhile, the Moon's orbit is continuing to grow, by about one and a half inches per year, and so the lunar month is getting longer. What's going on is that the Moon is trying to get even and give Earth its own far side. That will happen when Earth's rotation rate has slowed enough to be equal to the Moon's orbital period. The Earth-Moon system will then have achieved a "double tidal lock." This never-invented wresting hold may sound rare, but it's actually common, particularly among double-star systems in our galaxy. Right here in our own backyard, Charon has managed to lock Pluto just as Pluto has locked Charon.By the time the Moon tidally locks Earth, the system will have slowed down so much that the Earth day and the lunar month will both last almost fifty, present Earth days, greatly simplifying the calendar. Long before that, though, the Sun will become a red giant and vaporize the Earth-Moon system. But let's ignore that complication.
Earth's rotation will continue to slow down, and the Moon will continue to spiral away until the Earth day exactly equals the lunar month. At that time, one Earth rotation will last over 1000 hours, which would require 4 million leap seconds per day. No need to panic just yet. You have over a trillion years to think about it.
I prefer Monn!
Dr Eriksson, of the Australia National University in Canberra, explains the evidence as due to variations in the pull of the Moon depending how far or how close the satellite was to Earth in its orbit. He told BBC News Online: "In my mind this represents unambiguous evidence for tides on Earth some 3,200 million years ago, and implies the presence of the Moon in orbit around the Earth at that time." The analysis of the tidal patterns also suggests that the duration of the lunation, the length of the lunar month, was 20 days as opposed to the 27.5 days today.