Book 6, Question 3
Why Do Tides Go in and Out?
The Moon tugs on Earth's oceans, and the water bulges toward it. Earth turns under those bulges. So a beach sees the bulge as high tide, and the water line rises and falls.
From the book
Page from A Million Whys Book 6
More fun facts
- The Moon's gravity pulls the oceans into bulges, one on the side of Earth nearest the Moon and one on the far side.
- Tides rise and fall as Earth's land spins through those bulges of water.
- Twice a month, when Earth, the Sun and the Moon line up, extra high tides called spring tides happen.
- During spring tides, the low tides are extra low too.
- High tides do not line up exactly with where the Moon is in the sky.
Sources: NASA Science, NASA Science, NOAA
Questions kids ask
What are spring tides?
Extra high and extra low tides that happen twice a month when Earth, the Sun and the Moon line up.