Mars

Mars is the fourth planet from the sun, and is also known and the Red Planet. Before we started to explore mars, it was the best candidate for harboring extraterrestrial life. One thing that brought attention to Mars is that astronomers thought they saw straight lines crisscrossing on Mars’s surface. This lead people to believe that those straight lines were made by some kind of intelligent beings. A radio broadcast in 1938 convinced enough people to believe it. #1

"For hundreds of years our observations of Mars were restricted by the vast distance separating Earth from the red planet. About once every two years, at its closest approach (called opposition), Mars passes within about 55 million km of Earth and it is then that we are able to capture pictures of maximum resolution with earth-based telescopes. The Hubble Space Telescope now provides us with excellent views from earth-orbit, but until the launching of probes to Mars to collect and relay data back to Earth, much of what was "known" about Mars was based on fuzzy pictures which showed only large scale planetary features and events. Some of the earth-based observations were: orbital and rotational dynamics, atmospheric phenomena, seasonal variations in the polar caps, variations in surface color (which were explained by theories ranging from the presence of vegetation, to water bodies linked by martian-made canals, to variations in surface composition); all of which resulted in a variety of interpretations. Atmospheric pressure and composition, as well as surface temperature, was studied using spectroscopy, but there was much debate about the varied results obtained by different studies. The earth-based observations of Mars paved the way for spacecraft exploration of the planet. So many questions had been raised about Mars and there were so few answers. Did life exist on Mars in the past or present? Was water present on the planet? If so, what form was it in? What was the atmosphere composed of and what were its dynamics? Could Mars be used to tell us more about the evolution of both Earth and our solar system? These were some of the questions which captured the imaginations of scientists from many disciplines, and the answers could only be found by direct observation. Judging by the reaction to the H.G. Wells "War of the Worlds" radio broadcast, the public was not immune to the mysteries of Mars either. Fueled by the curiosities of both the scientific community and the public, on November 28, 1964 at 9:22 EST Mariner 4 was launched and 228 days later it would become the first spacecraft ever to visit the red planet."#5

"Scientists know generally how mars evolved after it formed about 4.6 billion years ago. Their knowledge comes from studies of craters and other surface features. Features that formed at various stages of the planet's evolution still exist on different parts of the surface. Researches have developed an evolutionary scenario that accounts for the sizes, shapes, and locations of those features."#4

Mars has a mass of 7.08 X 1020 tons (6.42 X 1020 metric tons). The latter number would be written out as 642 followed by 18 zeros. Earth is about ten times as massive as Mars. Mars density (mass divided by volume) is about 3.933 grams per cubic centimeters. This is roughly 70 percent of the density of Earth. #4

Mars is a lot like Venus, it is very bright, so it's easily spotted in the night sky. And since it's this way, nobody really knows who exactly discovered it. We do kow it was named after the Roman god af war. thats because of its redish color, which reminded people of blood. #2

Since Mars is so much smaller and less dense than Earth, the force due to gravity at the surface of Mars is only about 38 percent of that on earth. Thus, a person standing on Mars would feel as if his or her weight had decreased by 62 percent. And if that person dropped a rock, the rock would all to the surface more slowly than the same rock of that on Earth. #4  Mariner 4 obtained the first images of Mars in 1964. Mariners 6 and 7 were able to get even more information in 1969. Mariner 9 was the first to orbit Mars. It studied Mars for about a year. It was launched in 1971. Mariner 9 was also the first to find information about Mars' two moons. #3

As time goes on, we keep getting more and more information about Mars. Like in 1965, we were able to capture 22 close up photos of Mars. Those photos were of Mars’s surface and all it showed on the surface was many craters, and naturally made channels. #1

“When viewed without a telescope, Mars is a reddish object of considerably varying brightness. At its closest approach to earth (55 million km), Mars is, after Venus, the brightness object in the night sky. Mars is best observed when it is at opposition and also at it’s closest. Such favorable circumstances repeat about every 15 years when the planet comes to perihelion (its closest approach to the sun) almost exactly at oppositions.”#3 **__ The search for life on Mars. __** “The idea that life could, or even does, exist on Mars has a long history. In 1877 the Italian astronomer Giovanni Schiaparelli claimed to have seen a planet wide system of channels. The American astronomer Percival Lowell then popularized theses faint lines as canals and help them as proof of vast attempt by intelligent beings to irrigate an arid planet, and various other alleged proofs of life on Mars have turned out to be equally illusory.”#1 Scientist have found strong evidence that water once flowed on the surface of Mars. The evidence includes channels, valleys, and gulleys. #1

The average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F). The average temperature on Mars is -63 degrees C (-81 degrees F). #2
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 * __This is what the atomsphere of Mars is made up of.__ Earth compared to Mars. **

 The atomsphere on Mars is about 100 times less dense than the atomsphere that Earth has. But Mars is dense enough to support it's own weather system which includes wind and clouds. Sometimes dust storms can ouccur on Mars. #4.
 * Carbon Dioxide (CO2): 95.32%
 * Nitrogen (N2): 2.7%
 * Argon (Ar): 1.6%
 * Oxygen (O2): 0.13%
 * Water (H2O): 0.03%
 * Neon (Ne): 0.00025 %

Just like all of the other planets do, Mars travels around the sun in an elliptical orbit. But the orbit of Mars is a little bit bigger or stretched out. Mars travels around the sun every 687 days. So a year on Mars at 687 days is much longer than a year on Earth at 365 days. Also just like on Earth, Mars rotates on it's axis from east to west. The solar days on Mars is 24 hours 39 minutes and 35 seconds. That is the time it takes Mars to rotate clear around once.#4

"Mars has two tiny moons, Phobos and Demos. The american astronomer Asap h Hall discovered them in 1877 and named them for the sons of Ares. Both sattellites are irregulary shaped. The largest diameter of Phobos is about 17 miles, Deimos is 9 miles acrossed."#4 figure 2 to the left is just a plain image of mars

site#1- Mars Introduction. 2008. 4 Feb.2009 . site#2- Planet Structure 1997 Windows to the universe .5 Feb. 2009. . site#3- Pos: INFORMATION. 2001. March 5 2009. Thinkquest. <[]>. site#4- NASA-Mars 29 Nov. 2007. NASA. 8 Feb. 2009. < http://www.nasa.gov/worldbook/mars_worldbook.html>. site#5- The history of Mars exploration. 06 Jan. 2005. March 5 2009. .
 * __References__**

figure#1-By James E. Tillman. September 23rd 1997. [|<www-k12.atmos.washington.edu/ k12/mars/index.html>] figure#2-published by Nick Lomb. July 24th 2006. [|<www.sydneyobservatory.com.au/ blog/?p=67>] ||
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