A hydrosphere is the total amount of water on a planet. The hydrosphere includes water that is on the surface of the planet, underground, and in the air. A planet's hydrosphere can be liquid, vapor, or ice.

On Earth, liquid water exists on the surface in the form of oceans, lakes and rivers. It also exists below ground—as groundwater, in wells and aquifers. Water vapor is most visible as clouds and fog.

The frozen part of Earth's hydrosphere is made of ice: glaciers, ice caps and icebergs. The frozen part of the hydrosphere has its own name, the cryosphere.

Water moves through the hydrosphere in a cycle. Water collects in clouds, then falls to Earth in the form of rain or snow. This water collects in rivers, lakes and oceans. Then it evaporates into the atmosphere to start the cycle all over again. This is called the water cycle.
hydrosphere
Catch a wave, and you're sitting on top of the hydrosphere.

Hydrosphere in Space
Some scientists believe a hydrosphere exists on Europa, a moon of Jupiter, that consists of a frozen outer layer and a giant, liquid ocean underneath it.

aquifer
Noun

an underground layer of rock or earth which holds groundwater.
atmosphere
Noun

layers of gases surrounding a planet or other celestial body.
cloud
Noun

visible mass of tiny water droplets or ice crystals in Earth's atmosphere.
cryosphere
Noun

icy part of the Earth's waterincluding icebergs, glaciers, and ice caps.
Earth
Noun

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

moon of Jupiter.
evaporate
Verb

to change from a liquid to a gas or vapor.
fog
Noun

clouds at ground level.
glacier
Noun

mass of ice that moves slowly over land.
groundwater
Noun

water found in an aquifer.
hydrosphere
Noun

all the Earth's water in the ground, on the surface, and in the air.
ice
Noun

water in its solid form.
iceberg
Noun

large chunks of ice that break off from glaciers and float in the ocean.
ice cap
Noun

area of fewer than 50,000 square kilometers (19,000 square miles) covered by ice.
Jupiter
Noun

largest planet in the solar system, the fifth planet from the Sun.
lake
Noun

body of water surrounded by land.
liquid
Noun

state of matter with no fixed shape and molecules that remain loosely bound with each other.
ocean
Noun

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

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

liquid precipitation.
river
Noun

large stream of flowing fresh water.
snow
Noun

precipitation made of ice crystals.
vapor
Noun

visible liquid suspended in the air, such as fog.
water cycle
Noun

movement of water between atmosphere, land, and ocean.
well
Noun

a hole drilled in the Earth to obtain a liquid or gaseous substance.

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    Writers

    Kim Rutledge
    Tara Ramroop
    Diane Boudreau
    Melissa McDaniel
    Santani Teng
    Erin Sprout
    Hilary Costa
    Hilary Hall
    Jeff Hunt

    Illustrators

    Mary Crooks, National Geographic Society
    Tim Gunther

    Editors

    Jeannie Evers, Emdash Editing
    Kara West

    Educator Reviewer

    Nancy Wynne

    Producer

    Caryl-Sue, National Geographic Society

    Sources

    Dunn, Margery G. (Editor). (1989, 1993). "Exploring Your World: The Adventure of Geography." Washington, D.C.: National Geographic Society.

    Last Updated

    Feb. 9, 2011

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