profile of the Earth’s atmosphere

Atmosphere: layer of air that surrounds the Earth and is composed mainly of nitrogen (78%) and oxygen (21%); its density decreases with altitude.

space probe

Unmanned craft launched in the direction of a celestial body in the solar system for purposes of studying it.

artificial satellite

Observation spacecraft placed in orbit around the Earth.

space shuttle

It orbits at an altitude of about 250 mi.

aurora

Luminous phenomenon that occurs at high altitudes near the Earth’s poles.

shooting star

Luminous trace produced when a meteorite burns up as it enters the Earth’s atmosphere.

airliner

Commercial aircraft that makes regular flights of variable duration, depending on the distance covered; it flies at altitudes of 39,000 feet.

ozone layer

Layer of gas that absorbs a large part of the Sun’s ultraviolet rays.

Mt Everest

The world’s highest peak rises to an elevation of 29,035 feet.

supersonic jet

Aircraft whose cruising speed is faster than the speed of sound; it flies at altitudes of 62,000 feet.

cloud

Fine droplets of water or ice crystals suspended in the atmosphere.

sea level

Average height of seawater observed for a given time (day, month, year); it is used as a reference point to define coastal features and measure land elevations.

troposphere

The most dense layer, which produces most of the meteorological phenomena and where temperatures decrease with altitude.

stratosphere

Highly stable layer of air where temperatures increase with altitude due to the absorption of solar radiation by the ozone layer.

tropopause

The boundary between the troposphere and the stratosphere; its altitude varies depending on the season, ground temperature, latitude and atmospheric pressure.

stratopause

Thin transition layer between the stratosphere and the mesosphere.

mesosphere

The atmosphere’s coldest layer, where temperatures decrease with altitude.

mesopause

Thin transition layer between the mesosphere and the thermosphere.

thermosphere

Layer that absorbs a large portion of solar radiation, leading to a steady increase in its temperature.

thermopause

Thin transition layer between the thermosphere and the exosphere.

exosphere

The outermost region of the atmosphere, where low-density gases disperse into space.

temperature scale

altitude scale

Hubble space telescope

Telescope placed in orbit above Earth’s atmosphere (370 mi), making it possible to observe the universe as never before.