- Prof. Vaughan Pratt from Stanford University says the Moon would gradually slow down too, and its distance from Earth would reduce. In time, it would probably just fall onto our planet.
In fact, Earth really is slowing down. In its youth, it spun much faster: a day lasted only 6 hours. The Moon’s gravity causes ebbs and tides that gradually drop the speed of Earth’s motion. NASA calculated that day length increases by 2.3 ms every 100 years. After billions of years, days would become several times longer, and then our planet will, perhaps, stop completely.