12-1 Sci

Troposphere

The lowest layer of Earth's atmosphere where weather occurs and which is about 12 kilometers thick.

Stratosphere

The second layer of the atmosphere that extends from the top of the troposphere to about 50 kilometers; contains the ozone layer.

Mesosphere

The middle layer of the atmosphere, starting at 50 kilometers above Earth's surface and ending at 80 kilometers; protects Earth from meteoroids.

Thermosphere

The outermost layer of Earth's atmosphere, extending from 80 kilometers outward, where temperatures can reach up to 1,800°C.

Ozone

A form of oxygen with three atoms per molecule that is found in the stratosphere and absorbs UV radiation from the sun.

Altitude

The height above the Earth's surface, which affects temperature and atmospheric pressure.

Meteor

A meteoroid that burns up and leaves a glowing trail in the mesosphere, commonly referred to as a shooting star.

Ionosphere

The lower layer of the thermosphere that begins at about 80 kilometers above Earth’s surface and extends to about 400 kilometers.

Exosphere

The upper layer of the thermosphere that extends from about 400 kilometers outward into space.

Temperature Inversion

A phenomenon in the stratosphere where temperature increases with altitude due to the presence of ozone.