It comes from the word Greek (atmos) means
“vapour” and (sphaira) means “sphere”
It is a layer of a gases surrounding a planet/earth
or other material body, that is held in place by the
gravity of that body.
It helps protect living organisms from genetic
damages by solar ultraviolet, radiation, solar wind
and cosmic rays
What does it do?
Protects from Sun’s heat and Space cold
*day/night temperature would be extreme
without blanket of gases
Protects from Sun’s harmful rays
*solar (ultraviolet) would destroy all life if not
It composed of:
- fixed by bacteria
and lightning to produce
ammonia used in the
construction of nucleotides
and amino acids.
- used by organisms
- it is the most
abundant noble gas.
is bounded above by the tropopause, a boundary
marked in most places by a temperature inversion
(i.e. a layer of relatively warm air above a colder
one), and in others by a zone which is isothermal
is the lowest layer of Earth's atmosphere
is the second-lowest layer of Earth's
atmosphere. It lies above the troposphere and
is separated from it by the tropopause. This
layer extends from the top of the troposphere
at roughly 12 km (7.5 mi; 39,000 ft) above
Earth's surface to the stratopause at an altitude
of about 50 to 55 km (31 to 34 mi; 164,000 to
The mesosphere is the third highest layer of
Earth's atmosphere, occupying the region
above the stratosphere and below the
thermosphere. It extends from the stratopause
at an altitude of about 50 km (31 mi; 160,000
ft) to the mesopause at 80–85 km (50–53 mi;
260,000–280,000 ft) above sea level.
is the second-highest layer of Earth's
It extends from the mesopause (which
separates it from the mesosphere) at an altitude
of about 80 km (50 mi; 260,000 ft) up to the
thermopause at an altitude range of 500–1000
km (310–620 mi; 1,600,000–3,300,000 ft).
Is the outermost layer of earth's atmosphere
It extends from the exobase, which is located
at the top of the thermosphere at an altitude of
about 700 km above sea level, to about 10,000
km (6,200 mi; 33,000,000 ft) where it merges
into the solar wind.