Physical Science - Module 3

Atmosphere

The mass of air surrounding a planet.

Atmospheric Pressure

The pressure exerted by the atmosphere on all objects within it.

Barometer

An instrument to measure atmospheric pressure.

Homosphere

The lower layer of earth’s atmosphere, which exists from ground level to roughly 80 kilometers (50 miles) above sea level.

Heterosphere

The upper layer of earth’s atmosphere, which exists higher than roughly 80 kilometers (50 miles) above sea level.

Troposphere

The region of the atmosphere that extends from ground level to roughly 11 kilometers (7 miles) above sea level.

Stratosphere

The region of the atmosphere that spans altitudes of roughly 11 kilometers to 48 kilometers (30 miles)

Mesosphere

The region of the atmosphere that spans altitudes of roughly 48 kilometers to 80 kilometers (50 miles).

Jet streams

Narrow bands of high-speed winds that circle the earth, blowing from west to east.

Heat

Energy that is transferred as a result of temperature differences.

Temperature

A measure of the energy of random motion in a substance’s molecules.

Thermosphere

The region of the atmosphere between the altitudes of roughly 80 kilometers and 460 kilometers.

Exosphere

The region of the atmosphere above an altitude of roughly 460 kilometers.

Ionosphere

The region of the atmosphere between altitudes of roughly 65 kilometers and 330 kilometers, where the gases are ionized.