Ability to do work, which is the ability to exert a force causing displacement of an object.

The force by which a planet or other body draws objects toward its center.

The region around a planet dominated by the planet's magnetic field.

A colorless, transparent, odorless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.

A colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light.

The process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.

An object that orbits a planet or something else that is not a star

The range of distance with the right temperatures for water to remain liquid.

Extends from the top of the troposphere to about 50 km (31 miles) above the ground.