The Earth's rotation and the gravitational pull of the sun and moon create tides. Because the moon is much closer to Earth than the sun, the moon exerts a much stronger gravitational pull.

The Earth's oceans respond to the moon's gravitational pull by bulging and dipping as the moon rotates around the Earth. As the ocean bulges toward the moon, a high tide is created. The high tide on the side of the Earth facing the moon is called the high high tide. The high tide caused by the bulge on the opposite side of the Earth is called the low high tide. (A low high tide may be understood as the moon's tidal force pulling the planet—not the ocean—toward it.)

Noun

our planet, the third from the Sun. The Earth is the only place in the known universe that supports life.

exert
Verb

to force or pressure.

gravitational pull
Noun

physical attraction between two massive objects.

high high tide
Noun

tide created when the Earth directly faces the moon.

high tide
Noun

water level that has risen as a result of the moon's gravitational pull on the Earth.

low high tide
Noun

tide created when the Earth faces away from the moon.

Moon
Noun

Earth's only natural satellite.

Noun

large body of salt water that covers most of the Earth.

Noun

large, spherical celestial body that regularly rotates around a star.

rotate
Verb

to turn around a center point or axis.

Noun

object's complete turn around its own axis.

Noun

star at the center of our solar system.

tidal force
Noun

gravitational pull exerted by one object, such as the sun or moon, that raises tides on another object, such as the Earth.

Noun

rise and fall of the ocean's waters, caused by the gravitational pull of the moon and sun.