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Our obsession over Mars is a result of its closet 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 reddish color of Mars' surface that lead to its name- Mars was the Roman god of war. When it is at its closest, Mars is only a mere 34,600,000 (55,700,000 kilometers away). Venus is the only planet which comes closer to us.
To add to the possibility of life, conditions on Mars are more like those on Earth than conditions on any other planet. (Fortunately or unfortinuately, we still would not survive on Mars.) While Earth's surface temperature ranges from -126.8 degrees Fahrenheit to 136 degrees Fahrenheit, Mars' temperature rarely rises above 32 degrees Fahrenheit. There is no visible water running on its surface, but scientists believe it may have existed millions of years ago and now exists frozen under the polar caps or surface. Mars' surface is characterized by three distinctive regions- bright areas, dark areas, and polar caps.
The bright areas cover about two-thirds of Mars' surface. They contain limonite, a reddish rust-brown mineral, that give Mars its red color. They are very dry, resembling our deserts with dust, sand, and rocks.
Covering one-third of Mars' surface, the dark area, called maria (seas), changes colors depending on the season Mars. During the Martian fall and winter, the maria may turn so light that they disappear. During the spring and summer, it becomes dark. Typically, the dark areas look greenish-gray or bluish gray. Astronomers believe these color changes are because of the wind. They believe that the wind will blown sand around, covering and uncovering parts of Mars' surface. In 1877, Giovanni V. Schiaparelli noticed many lines criss-crossing Mars' dark area. He called these lines "channels", but when it was translated from Italian to English, it became "canal". This lead to the misconception that Mars actually had canals running through its maria. Many people took that to mean Mars was inhabited.
The polar caps on Mars take up a small area near its north and south pole. From Earth, these caps look white, leading scientists to believe there may be large quantities of water frozen there. Like the maria, the polar caps change with the seasons. During the spring and summer, when Mars is tilted towars the sun, the polar caps evaporate and shrink. During the fall and winter, they freeze again and grow larger. The evaporation during the summer and spring may actually be providing water vapor in Mars' atmosphere.
Besides the three regions, Mars also has numerous craters from the impact of past meteorites. The surface also has canyons, gorges and features that resemble dry riverbeds. This provides further support to the belief that Mars once had water flowing on it. Volcanos are also present on Mars, mainly on near the eqautor. These volcanos are much larger the largest volcano on Hawaii. In fact, the largest volcano on Mars is twice the size of Mount Everest, the tallest mountain on Earth.
Another 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.