EARTH

Earth is the third planet from the Sun and the fifth largest in the solar system, notable for being the only known planet to support life. It is an "ocean world" with about 71% of its surface covered by water, and it has a protective atmosphere, a magnetic field, and tectonic plates that drive geological activity. Earth is shaped like an oblate spheroid, rotates on its axis to cause day and night, and orbits the Sun to complete a year.

WATER

THE SOURCE OF LIFE

About 71% of Earth's surface is water-covered, and oceans hold over 96.5% of all water on the planet, which is saline. The remaining freshwater is mostly trapped in glaciers and ice caps (68% of fresh water), with a significant portion stored as groundwater (30.1% of fresh water). A very small percentage is in lakes, rivers, and the atmosphere.