Friday, May 13, 2016

Mars the Red Planet

The planet Mars is similar to Earth in the sense it has ice caps, desert plains, mountain ranges, volcanoes, and canyons.The planet has captivated astronomers and science fiction writers for years. This planet was named after the Roman God of war probably because of its red color.NASA intends to do a Mars landing with astronauts. This has the possibility of being bigger than the Mars Pathfinder Mission in 1997. Mars is a terrestrial planet. Its physical size is smaller than Earth. The magnetic fields on Mars are weak compared to other planets. This was discovered by examining residual magnetism in older rocks. There is a possibility that it was stronger at one time. There is also speculation that a planetary disaster caused Mars to become the dry and dusty place it is now. Some how it was initiated by the loss of the magnetic filed when the iron core froze. Then the solar winds changed the planet. The diameter is 6,780 km with a mass 0.11 times Earth. One is about 687 Earth days. Internally the planet consists of solidified iron core, rocky crust, and a silicate mantle.Mars seems to be the best candidate for terraforming. At the moment it is beyond human technological ability, but in the future it could be a reality. More needs to be known about Mars for such an ambitious project to take place. Humanity has gather for now, a sizable portion of knowledge on the red planet.
       Mars has an atmosphere composed of carbon dioxide, nitrogen, and argon. Carbon dioxide is estimated to be about 95.7%  and nitrogen 2.7 % of the total atmosphere. Argon is only 1.6% of the atmosphere of Mars. Besides a harsh atmosphere, dust storms can be intense. The air of  Mars is thin and has enough density to form weather. The accumulation of high winds exacerbate the sands of Mars. The red sand covers the majority of the surface, which means dust storms can be both regional or planet wide. The atmosphere does contain diminutive amounts of oxygen, carbon monoxide, and even water vapor. Spectroscopy was helpful in discovering the nature of the Martian atmosphere, before the rise of spacecraft. The surface temperature can be 70k cooler than that of Earth. Mars has a high level of ultraviolet radiation making it hard for life to develop or thrive there. Solar winds can go up to supersonic speeds creating an environment of violent weather.

The atmosphere seems inhospitable, but the surface also is a difficult place. There is no vegetation or water. Water could have existed at one time on the planet according to the findings of the Viking orbiters. What they found were runoff channels and outflow channels.Runoff channels are large in length extending hundreds of kilometers on Mars.They are located in the southern hemisphere. The runoff systems are similar to the structure of rivers on Earth. The valley networks as some astronomers refer to them reveal a Mars that was once warmer and possessed a thicker atmosphere.
The outflow channels indicate that there was intense flooding.These structures appear at the equatorial region.        
       The red planet's surface is frozen rock desert surrounded by dunes and craters. Mars has volcanoes and canyons throughout the planet. Mars is a terrestrial planet of the inner solar system. The great part of Mars being close to Earth is that  surface features can be recognized as small as 100 km across. The suns rays still effect observation and topographical information is difficult to extrapolate. Mars's  surface can also be effected by seasonal changes. This is from the axial tilt of the planet and the unique nature of its orbit. The polar caps increase or decrease in size depending on the season. During the summer they decrease due to rising temperature. The polar ice caps are frozen carbon dioxide. This can be referred to as "dry ice." Water ice mixed in produce a swirling pattern, which indicates the direction of the winds. Mars does have some differences in structure in both its northern and southern hemispheres.The northern hemisphere contains mostly volcanic plains. These structures were probably formed by eruption of lava from surrounding volcanoes. Volcanic rocks are prevalent. The cratered highlands are native to the southern hemisphere. The craters could be the result of incoming meteoroids. The plains of the north are less cratered, which may mean that it is younger compared to the south. Astronomers estimate that the craters in the south are 4 billion years old and the the ones in the north are 3 billion years old.
      Mars is unique due to the fact it has enormous volcanoes. They are thought to be the largest documented in the solar system. The largest seen is known as Tharsis bulge and Olympus Mons . Olympus Mons is 700 km in diameter and stands at a height of 25 km. These volcanoes are on particular hot spots on the Martian mantle.Smaller volcanoes can be located in the northern plains. It is not lucid that these volcanoes are active. It appears in some observations that some have erupted only in the last few million years.Examining the caldera of Olympus Mons reveals the age of volcanic structures. The large central pit has five rings. The are remnants of the summit collapse, which was induced from eruptions of reservoir magma. The youngest ring has been estimated to be 140 million years old. Lava is believed to erupt through fissure on the side of Olympus Mons as far back as 20 million years ago. The volcanoes of Mars probably were active 100 million years ago. The shield volcanoes as they are classified are not the result of plates. The reason volcanoes on Mars achieved immense height is due to the nature of surface gravity. It is low, which results in lava weighing less and it can accumulate easier. The structure is dependent on how much weight it can support. Mars has a surface gravity value of 0.38 g that allows for volcanoes to be 2.5 times as high. 
        Mars also contains a vast canyon system. It makes the Grand Canyon look miniature in comparison. The most notable is the Valles Marineris canyon system. It was discovered in 1971 by the Mariner Probe 9. The valley began as a narrow slit in the crust. Tharsis Rise generated intense pressure. Water was at one time present allowing for erosion and the creation of sedimentary rocks. The absence of water ice may have caused landslides which caused valleys to increase in width. Mars becoming devoid of water and moisture 3 billion years ago caused major geological changes. There are also networks of basins as well. The recognizable structures include the ophir chasma and aureum chaos. The Ophir Chasma is located in the north side of a series of basins, which is at the center of the main canyon complex. Landslips could have possibly destroyed higher grounds in between canyons, that led to the formation of  Ophir Chasma and Aureum Choas. Mars has been geologically active for millions of years. 

The dimensions of the Mariner Valleys are 700 km wide . It is about 8 km deep. The total length is calculated to be 4,000 km. This is an impressive structure that could mean Mars was more than a dusty wasteland.  
        The most debated mysteries is the question of water on Mars. Runoff channels provide a clue. There are systems far in length that twist, connect, and merge. These systems seem similar to river systems of our planet Earth. Geologists have speculated that these are the remains of dried up rivers.Mars could have had an early period of rivers, lakes, and oceans on its surface. There is an opposite perspective. Other astronomers believe that these structures are the product of tectonic forces. The Mars Global Surveyor has revealed what could have been a delta. Findings also suggest that Mars has carbonate layers. This means that oxygen and carbon could have been in ancient oceans . There is a possibility today that Mars's water could be gathered into permafrost. The evidence for a permafrost layer could be the impact crater Yuty. It shows that liquid was in this crater, rather than an impression from other objects. A high temperature impact could have melted the permafrost. The appearance of  ejecta. Around 2002 there was another break through. The Mars Odyssey detected deposits of  water ice crystals. These were mixed with hydrogen and Martian surface layers. Ice appeared to be 50% of Mars's soil . This means that Mars once contained oceans located in polar regions. As more space craft is sent more is revealed about the former environment. 
     Mars has satellites, which are the moons known as Phobos and Deimos. First documented in 1877 , they project little light. The moons are heavily cratered, contain low density, and small. There infinitesimal size makes some astronomers convinced they are asteroids caught by Mars's gravitational force. The Martian moons contents include carbon rich rocks. 

    
Deimos orbits Mars in a total of 30.3 hours. This is at an altitude of 20,040 km. Phobos takes 7.66 hours to orbit. Its altitude is much lower calculated at 5,980 km. There still is debate if these are genuine moons. Further study is needed to determine the true nature of these objects.
     There remains another fascinating question. The possibility of life on Mars. It may have had life in the past. Life used in this context is not Earth centric. Not all life is carbon based that emerged from a liquid water environment. Mars as previously explained is a harsh biome. Liquid water is rare or generally limited. The atmosphere so thin enables high amounts of radiation to enter. Combined with the lack of ozone and magnetism creates a more unbearable environment. There is speculation by scientists that microorganisms could exist. The surface could have microbes that can digest oxygen rich compounds. This may explain why the Viking spacecraft did not detect organisms. The polar ice caps may possess life, but the Viking lander was not sent there. The Mars Pathfinder did not find life either. The Mars Pathfinder to much shock did find some water in the Martian North Pole. The planets of the solar system continue to full of surprises. Conclusions should not be reached until Mars can be explored more extensively. The question of life will still continued to be debated. There have been thousands of exoplanets discovered and some could be Earth like. It is not impossible that there could be life forms on other planets besides Earth. Mars may be what Earth will be like billions of years in the future. Whatever the circumstances of its development, Mars will continue to generate interest in the scientific community.   

Further Reading 

Chaisson, Eric. Astronomy Beginners Guide to the Universe. New York: Pearson, 2010. 

Rees, Martin. 30 Second Astronomy.  New York : Metro Books, 2014. 

Couper, Heather. Space Encyclopedia. New York: DK Publishing, 1999. 


                  


       

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