to: Intro, The
Atmosphere, Missions to Mars
Our obsession over Mars is a result
of its close proximity to us. The fourth planet from the sun and third
smallest in our solar system, Mars is the only planet who's surface can
be seen with great detail from Earth. It was the blood red color of Mars'
surface that led to its name- Mars was the Roman god of war. When it is
at its closest, Mars is only a mere 34,600,000 miles (55,700,000 kilometers
away). Venus is the only planet which comes closer to us. Because Mars has been so close to us, it has been studied greatly. As a result, there has been an obsession about the possibility of life on Mars.
One reason why mankind can not
survive on Mars is its thin atmosphere. Mars' atmosphere consists mainly
of carbon dioxide. Nitrogen, argon, oxygen, carbon monoxide, neon,
krypton, xenon, and water vapor make up the remainder. The atmospheric
pressure is around 0.1 pound per square inch, less than one-hundredth of
the pressure on Earth.
Mars' sky contains clouds just like
ours. There are three types of Martian clouds. Pink clouds of dust cover
the most area, but there are also blue clouds that are made up of ice
crystals and white clouds, believed to be made up of water vapor, which
move across the planet. Early fog occurs on Mars just as it does on Earth. They usually tend to form in the valleys of Mars during the morning. However, most of the fog will disappear as the day goes on and the sun rises. Frost is also common on Mars. Each winter, at the Viking Lander 2 site, a thin layer of water frost forms on the ground.
Scientists believe that at one point in time, Mars may have had a denser atmosphere that allowed water to flow on the surface. They point to evidence such as dried up shorelines, gorges, riverbeds, and islands.
MISSSIONS TO MARS:
Mars has been the focus of our attention for a long time. As early as 1965, probes have been sent to study Mars. In July 1965, Mariner 4 took 22 pictures of Mars. While the probe never landed on Mars, the pictures revealed what the surface was like. It also showed that there were NO lifeforms on Mars.
In July and September 1976, Viking Landers 1 and 2 landed on the surface of Mars. The landers conducted many scientific experiments that showed unexpected chemical activities in the soil. However, they failed to prove that microorganisms existed on Mars. These chemical activities are believed to be occuring as a result of the ultraviolet radiation Mars received from the sun. This, combined with the arid environment of Mars, does not support the theory of life on Mars.