A short day and a near Moon
The Sun rises every few hours, and the Moon looms far larger than it does now.
- When
- Known to
- ± 150 million years
- Era
- Eoarchean, Archean
Tidal friction has been slowing Earth's spin and pushing the Moon away since the impact that formed it. In the Eoarchean the day is thought to have lasted well under twelve hours and the Moon orbited substantially closer, raising tides far higher than today's. The Moon still recedes about 3.8 centimetres a year, and the day still lengthens by roughly 1.8 milliseconds a century.