The most recent chapter in the story, the exploration of Mars by unmanned spacecraft, has dispelled such notions but has no diminished our fascination. Mars is the fourth planet from the Sun, orbiting at about 1.
It is considerably smaller than Earth and Venus and has only a thin atmosphere. It has two tiny moons, Phobos and Deimos, which were discovered in Earth-based telescopic observations of Mars revealed that its axial tilt and length of day are very similar to those on Earth, and that the seasonal variations occur in surface markings and the polar ice caps.
The surface markings on Mars observed made some early observers to hypothesize the existence of a global system of canals.
Thus Mars has been the subject of intense speculation about possible civilizations or alien life-forms. Thus, Mars has been explored by interplanetary probes, primarily from the United States. But the greatest detail came from the U. Viking probes in , which included orbiters and landers conducting observations and experiments on the surface for several years Young, Mars has a very thin atmosphere the pressure at the surface is only 0.
But the Martian atmosphere was once much thicker than it is today, which would have made the surface warmer as a result of the greenhouse effect. The water vapor is minimal, but some water ice is present in the Martian polar caps, which are composed chiefly of frozen CO 2 dry ice. It has complex and variable winds much of the time, but they have relatively little impact because of the thinness of the atmosphere.
Mars is farthest from the Sun when it is summer in the northern hemisphere and winter in the southern hemisphere. Mars is closest to the Sun when it is winter in the northern hemisphere and summer in the southern hemisphere. Therefore, the seasonal variations are relatively mild in the northern hemisphere but extreme in the southern hemisphere Leovy, The surface is barren and rocky, with many impact craters.
There are also several large volcanoes seen on Mars. The largest, called Olympus Mons, is 27 km tall over three times the height of Mt. Everest and has a base km in diameter. There are also shield volcanoes similar to those that form the Hawaiian Islands. But the reason they are so much bigger on Mars is that there is no continental drift to carry the mountains away from the subsurface volcanic vents that formed them.
The evidence for tectonic activity on Mars is minimal. Today there is no widespread system of crustal plates and no evidence of crustal motion similar to continental drift.
But scientists dispute how recent volcanic activity may have ceased on Mars. Some believe there may have been eruptions within the past billion years while others suggest all the activity stopped more than 3 billion years ago. Further, close-up examination of the Martian surface was accomplished by the two Viking missions. The photographs of the surface rocks and dust showed that they are quite reddish in color, due to high concentrations of iron oxide.
Hence, this explains the overall color of the planet Young, According to scientists, water should have been present from early times. Its origins were in the venting of gases from the interior of the planet and from accretion of icy bodies from space. There are ancient, dry river channels that are seen today on Mars, particularly along the edges of the southern highland regions.
Some fold plains are also evident. Some valleys, including portions of Valles Marineris, show signs of ancient beaches where there once was standing water in the form of large lakes. But scientists argued that if there had been liquid water on Mars, the atmosphere must have been much thicker, and the current atmosphere on Mars is too thin to prevent liquid water from evaporating quickly.
Some or all of the water present today may be in the form of subsurface ice. This is called permafrost, and similar subsurface deposits are found in arctic regions on Earth.
There are regions on Mars where it appears that subsurface ice has suddenly melted, causing the surface to collapse and thus the resulting jumbled areas are called chaotic terrain Pollack, Scientists observing from Earth could not establish evidence of Martian life.
They explained the dark surface markings and the seasonal variations in other ways. The Viking missions conducted searches for microscopic life-forms in Martian soil samples and found no organic molecules in the soil. Although no evidence for life was found, the possibility that life once existed on Mars was not ruled out. The fact that Mars once had liquid water and a denser, warmer atmosphere suggests that primitive life-forms might once have existed there.
Thus, future missions may be designed to look for fossil microorganisms Caplinger, , Conclusion section. The mysterious red planet is still mysterious, but in new ways. Most of the age-old questions related to its changing appearance, the possibility of civilizations thriving on its surface, and its distinctive color have been answered through close-up examination.
What scientists have found is a planet like the Earth, except one not as fully developed, in the geological sense. But the interest awakened about the planet has not subsided, and, after the Moon, it will probably be the next body in the Solar System to be visited by astronauts. Malin Space Science Systems. The atmosphere of Mars. It is often referred to as the Red Planet. This paper will inform you about the physical characteristics of Mars, the exploration of Mars, the moons of Mars, and the possibility of life existing on Mars.
The atmosphere of Mars is very different than that of Earth. The atmosphere of Mars is mostly composed of carbon dioxide. Williams, The Mars atmosphere is so thin that it cannot hold heat.
This causes the low temperatures on Mars because the atmosphere cannot sustain a strong greenhouse effect and it only raises the temperature about five degrees Kelvin. The average temperature on Mars is negative fifty-five degrees Celcius, which is about sixty-seven Faranheit. McKay, Mars is also famous for its windstorms. Sometimes one of its very strong wind and dust storms will engulf the entire planet for months.
The terrain of Mars is one of the most varied and interesting of any of the terrestrial planets. However the northern hemisphere consists of plains, which are much younger and also lower in elevation. McKay, There are four main geological features on Mars. The most famous is probably Olympus Mons.
Olympus Mons is an extinct shield volcano that rises more than twenty-four km and it is the tallest mountain in the solar system Arnett, Mars is also home to the largest canyon in the solar system, Valles Marineris. Valles Marineris is 4, km long and seven km deep. Sheehan, The other two main geological features of Mars are 1 Tharsis:
Mars is the fourth planet from the sun. It orbits the sun at a span of about million miles. Looking up at Mars from Earth the planet Mars appears fiery red. The surface is almost exactly the same as the dry land on Earth. The time it takes Mars to rotate once on its axis is about half on hour longer than an Earth day.
Free Essay: Mars, it’s where aliens come from, a Hollywood Sci-Fi mainstay, the mysterious red planet. But, what is Mars really? Mars is the fourth planet.
Mars And Venus I am following up on the book of, "Men are from Mars and Women are from Venus." by John Gray. "Men are from Mars and Women are from Venus" was been a very interesting book. - Life on Mars If life ever evolved on any of the other planets, Mars is the likeliest candidate. After Earth, Mars is the planet with the most hospitable climate in the solar system. So hospitable that it may once have inhabited primitive, bacteria-like life.
Essay on mars planet Halden August 13, Rocks on a history of mars. Religion necessary to mars one project: restoration ecology films. You inspiration mars and news bringing life could begin sterile planet. World of the planet that humans to know essay writing a florida beach. , lakewood, the red planet. Planet Mars Essay Sample Introduction For a long time, it was thought that Mars, the red planet, was inhabited by extraterrestrial beings, the “martians,” who had built an extensive network of “canals” on the planet’s surface.