Weather in Space

The Moon

How often do ocean tides occur on Earth?

During a 26-hour period, each point on Earth’s surface moves through a series of two high tides and two low tides—first high, then low, then high again, then low again. The length of the cycle is the sum of Earth’s period of rotation, or the length of its day (24 hours), and the Moon’s eastward orbital movement around Earth (two hours).


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