|
Atmosphere Mars
The atmosphere of Mars is comparatively
thin and the air pressure on the surface is only
750 Pascal, about 0.75 percent of the average
on Earth. Though, the scale height of the atmosphere
is about 11 km, fairly higher than Earth's 6 km.
The constituents of Mars include
95 percent carbon dioxide, 3 percent nitrogen,
1.6 percent argon, and traces of oxygen and water.
Methane was apparently discovered in the atmosphere
by Earth-based telescopes In 2003, and perhaps
confirmed in March 2004 by the Mars Express Orbiter,
present measurements state an average methane
concentration of about 11±4 ppb by). The
thin atmosphere cannot embrace heat and is the
cause of the lower temperatures on Mars. The presence
of methane on Mars would be very fascinating,
since as an unstable gas it indicates that there
must be a source of the gas on the planet.
Volcanic
activity, comet impacts and the existence of life in
the form of microorganisms such as methanogens are among
possible however as yet unconfirmed sources.
The methane appears to occur in patches, which suggests
that it is being hastily broken down before it has time
to become uniformly distributed in the atmosphere. |
|
In the winter months when the
poles are in continual darkness, the surface gets
so cold that as much as 25% of the entire atmosphere
condenses out into meters thick slabs of CO2 ice.
When the poles are again exposed to sunlight the
CO2 ice sublimates, creating massive winds that
sweep off the poles as fast as 250 mph. These
continuing actions transfer large amounts of dust
and water vapor giving rise to Earth-like frost
and large cirrus clouds.
|
