THE PLANET MARS
Mars, as we knew it before the present space age, was a world of heroes, creatures, and a fading civilization, which built canals to save its diminishing water supplies. Today, the mysteries of the planet and its canals are gone. Spacecraft images of a red landscape, deserts, craters, huge volcanoes, and a barren lonely world show the real Mars; a planet midway between the Earth and the Moon in size and surface conditions (Dickinson 1998). Mars is also known as the Red Planet and Ares (the god of war), most likely because of its distinct red appearance. Being the second closest planet to Earth and the most probable to harness life, Mars is an exciting planet, which may in fact have a remarkable impact on the future of human exploration.
Mars is smaller then Earth and has an elliptical orbit, which means the distance between Earth and Mars can vary anywhere from 0.37 to 0.68 AU. One result of this elliptical orbit is a rather large temperature variation, which has a major influence on the planets climate. Though the average temperature on Mars is about 218 K (-55 C), Martian surface temperatures range widely from 140 K (-133 C), at the winter pole to almost 300 K (27 C), in the day during summer (Arnett 2003). The atmosphere of Mars is much different then Earthís. The six most common components of the atmosphere are: Carbon Dioxide (CO2): 95.32%, Nitrogen (N2): 2.7%, Argon (Ar): 1.6%, Oxygen (O2): 0.13%, Water (H2O): 0.03%, and Neon (Ne): 0.00025 %. The air on Mars only contains about 0.001 as much water as the air on Earth, but even this small amount can condense and form clouds. The Viking Landerís 1 and 2, which landed on Mars in 1976, recorded that a thin layer of water frost covers the ground each winter on the planet (Hamilton 2001).
There is some evidence that in the past water flowed on the surface of Mars. Physical features bear a resemblance to shorelines, riverbeds, and even islands suggest that great lakes and rivers once covered the planet.
Another interesting condition of the planets surface is the low and varying atmospheric pressure. The barometric pressure tends to vary at each landing site on the Red Planet. Carbon dioxide, the main element of the atmosphere, freezes to form a huge polar cap, alternately at each pole. The carbon dioxide at the poles form a snow cover and when the spring arrives the snow evaporates. All recorded averages of daily pressure by the Viking Landers 1 and 2 were very low, hovering at an average of 7 millibars. This is equivalent to less then 1% of Earths atmospheric pressure (Arnett 2003). Although the pressure is rather low, it is still thick enough to support very strong winds and immense dust storms that can cover the planet for months at a time. The thin atmosphere on Mars produces a slight greenhouse effect, which increases the surface temperature when incoming solar radiation enters, but the atmosphere blocks outgoing thermal radiation. This weak greenhouse effect on the planet is only strong enough to raise the surface temperature by about 5 degrees K.
Not all conditions on Mars are excessively different than our home planet Earth. In space there is no gravity. According to Dr. Victor Schneider, research medical officer for NASA headquarters, humans in zero gravity for long periods of time may develop health problems like bone shrinking and the destruction of bone tissue (1999). Gravity on Earth is 1g, and seeing that the surface of Mars is 0.38g, human beings will more then likely be able to live with no serious side effects. Plants do not need gravity to survive, so they will be able to grown comfortable at such gravity. One day on Mars is rather similar to an Earth day. At the equator of Mars, one day is only 30 minutes longer then an Earth day. Because Mars has a day and night cycle similar to Earth, agriculture would be able to grow without disruption to its natural sun intake. As mentioned, the surface of Mars is a reddish colour. The soil and surface of Mars is covered with rust, which contains vast amount of iron. This soil would be very fertile for agriculture because of the high concentrations of phosphorus, calcium, magnesium, sulphur, iron, manganese, zinc, copper and even a minute amount of water.
The upper 10 centimeters of the Martian soil contains at least 3% water. This is enough to get water out of the soil by heating it up. To the north of the planet, the northern ice cap is mostly made up of water ice, which can be heated up to get liquid water (Chris 2000). What is most interesting about Mars is that it highly possible to terraform with today's technologies and a modest budget. Mar is the only planet we know of where this is possible.
Of all the planets in the Solar System, Mars is by far the only planet we can realistically colonize and make our second home. Mars has much to offer humans, and its natural environment, structure, and location make it possible for us to alter for the success of human colonization. With many similarities to Earth and all the elements needed for life, Mars is a world full of new opportunities and challenges for humans to expand upon. Over the years we have studied the planet and know much about it, now is the time to act. Now is the time for us to plan missions, which will forever change history. It is time to colonize Mars once and for all.