Mars

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Status: In Progress  |  Genre: Non-Fiction  |  House: Booksie Classic
Mars

Submitted: October 27, 2018

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Submitted: October 27, 2018

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Mars
Mars is called the red planet because of the red colour we see in images from space that show the result of iron rusting. Rocks and soil on the surface of Mars contained a dust composed mostly of iron and small amounts of other elements such as chlorine and sulhpur. The rocks and soil were eroded by wind and the dust was blown across the surface by ancient volcanoes. Recent evidence points to the very fine dust also being spread across the planet by water, backed up by the presence of channels and ducts across the surface of Mars.

The iron within the dust reacted with oxygen, producing a red rust colour, while the sky appears red as storms carried the dust into the atmosphere. This dusty surface, which is between a few millimetres and two metres deep, sits above hardened lava composed mostly of basalt. The concentration of iron in this basalt is much higher than that on Earth, contributing to the red appearance of Mars.

 

Mars is the fourth planet from the Sun, orbiting at a distance of 1.52 AU once every 687 days. It is our neighbour in the solar system, orbiting just outside the Earth's orbit, and it is a small planet – the second smallest in the solar system after Mercury, measuring 53% of an Earth-width in diameter. In the night sky, Mars appears with a distinctly red color, which is apparent even to the unaided eye. This is the result of a high abundance of iron oxide – better known as rust – in its soil.  Through a telescope, Mars's surface is a dull red color, though its polar regions often appear to have a markedly whiter hue. Its surface features appear as subtle dark markings on its surface, whose brightness contrasts are often easier to see with the help of color filters.  Mars rotates on its axis once every 24.5 hours, meaning that each day on Mars – commonly termed a sol – is only slightly longer than a day on Earth.  Mars has two small moons, Phobos and Deimos, which were discovered by Asaph Hall in 1877; they are named after the sons of Mars in Greek mythology.  Both are very small – less than 25 km across – and are very challenging objects to observe as they orbit very close to Mars.  It is unlikely that they formed at the same time as Mars. They are probably in fact asteroids which have been captured into orbit around the planet. Phobos orbits so close to Mars that it feels strong tidal forces which will probably rip it apart within the next 50 million years.

Space missions to Mars have been frequent.  This large number can primarily be attributed to Mars' proximity to the Earth, putting it within comparatively easy reach for interplanetary probes, as well the interest of its solid and possibly habitable surface returning with useful data.  Mars lies close to the Earth in the solar system, its distance from the Earth varies dramatically over this 780-day cycle.  When the two planets are next to one another in their orbits – the moment when Mars appears at opposition, their separation can be less than 0.4 AU, astronomical units miles kilometer.  By contrast, when the two planets are opposite one another in the solar system – the moment when Mars appears at solar conjunction – their separation can exceed 1.6 AU.  As a consequence, the size of Mars's disk , gas, plasma,  particles changes dramatically: at solar conjunction it is a small and distant speck measuring no more than six arcseconds across, while at opposition it measures up to four times that size. As Mars passes opposition, when it is closest to the sun and closer to earth. In orbit, its distance from the Earth changes most rapidly. As the Earth overtakes it, the two planets are only alongside each other for a couple of weeks. The Earth need only be a few degrees ahead of or behind Mars for the separation of the two planets to be significantly larger than at the moment of opposition. The chart below shows how Mars suddenly glides close to the Earth, before receding back to its usual distance just as quickly. The closer Mars is to the Earth, the larger it appears. Mars is closest to the Earth when at opposition.

Season variation.  As seen from the Earth, the variation in the distance of Mars from the Sun appears exaggerated by the fact that the Earth remains at an almost constant distance from the Sun, not far away. Mars's elliptical orbit gives rise to a much larger relative change in its distance from the Earth than it does in its relative distance from the Sun.

This elliptical revolving path means that Mars's closest approaches to the Earth do not always bring it to exactly the same distance from the Earth. When an opposition occurs at any given time of year, Mars – by the definition of an opposition – must lie immediately alongside the part of the Earth's orbit where the Earth is found at that time of year. For example, whenever Mars comes to an opposition in late August, it is always at roughly the same point along its orbit, next to where the Earth lies every year in late August. It so happens that this point is very close to the position where Mars makes its closest approach to the Sun – its perihelion. This also brings it closer to the Earth than is possible at any other time, and it may briefly come within a distance of 0.4 AU of us.  When Mars comes to opposition in August, we get much closer views of its surface and it appears considerably brighter than when it comes to opposition in February.


The ancient volcanoes of Mars.

Elysium Planitia is the second largest volcanic region on Mars. It is located on a broad dome that is 1,700 by 2,400 kilometers (1,060 by 1,490 miles) in size. The volcanoes Hecates Tholus, Elysium Mons and Albor Tholus can be seen going from north to south (top to bottom) in this image. Hectas Tholus is 160 by 175 kilometers (100 by 109 miles) in size with a caldera complex 11.3 by 9.1 kilometers (7 by 5.7 miles) in size. Elysium Mons is the largest volcano in this region. It has base dimensions of 420 by 500 by 700 kilometers (260 by 310 by 435 miles) and rises 13 kilometers (8 miles) above the surrounding plains. Its summit caldera is about 14.1 kilometers (8.8 miles) in diameter. Albor Tholus measures 160 by 150 kilometers (100 by 93 miles) with a summit caldera of 35 by 30 kilometers (22 by 19 miles). Its northwest flanks have been partially buried by lava flows from Elysium Mons. 

Olympus Mons is the largest volcano known in the solar system. It is classified as a shield volcano, similar to volcanoes in Hawaii. The central edifice of Olympus Mons has a summit caldera 24 kilometers (15 miles) above the surrounding plains. Surrounding the volcano is an outward-facing scarp 550 kilometers (342 miles) in diameter and several kilometers high. Beyond the scarp is a moat filled with lava, most likely derived from Olympus Mons. Farther out is an aureole of characteristically grooved terrain, just visible at the top of the frame.

The Majestic Olympus Mons This 3D image of Olympus Mons was created using the USGS color Mars mosaic and Mars digital elevation model. The final image shows Olympus as it would be seen from the northeast. It is possible that volcanoes of such magnitude were able to form on Mars because the hot volcanic regions in the mantle remained fixed relative to the surface for hundreds of millions of years.

Olympus Mons, 1998 Olympus Mons is a mountain of mystery. Taller than three Mount Everests and about as wide as the entire Hawaiian Island chain, this giant volcano is nearly as flat as a pancake. That is, its flanks typically only slope 2° to 5°.

Olympus Mons Caldera Mosaic This high-resolution image shows the Olympus Mons caldera located 24 kilometers (15 miles) above the surrounding martian plains. The caldera is about 80 kilometers across with walls that are 2.4 to 2.8 kilometers deep. Calderas are produced when the roof of the magma chamber collapses due to removal of magma by voluminous eruptions or subterranean magma withdrawal.


Ascraeus Mons Summit This complex caldera is composed of several discrete centers of collapse where the older collapse features are cross-cut by more recent collapse events. The lowermost circular floor preserves the last lava flooding event that followed the last major collapse. The southern wall of the caldera has at least 3 kilometers (1.9 miles) of vertical relief with an average slope of at least 26° (from horizontal). The caldera complex truncates several lava flows, indicating that the flows predate the collapse event and that their source areas have been destroyed by the caldera formation. 

Arsia Mons The caldera on Arsia Mons is considerably larger than the calderas on either Ascraeus Mons or Pavonis Mons. However, the last major collapse event on Arsia Mons was followed by a substantial outpouring of lava within the caldera. The caldera rim has been breached on the southwest side while the caldera floor lavas bury portions of the northeast rim. Aligned between these breaks in the caldera is a series of very subdued domes on the caldera floor, perhaps representing localized sources of the lava that flooded the caldera. The flaks of the shield have been deeply eroded near the locations of the breaks in the caldera rim and lava flows extend away from the volcanoes at these embayments.

Apollinaris Patera This view of Apollinaris Patera, shows characteristics of an explosive origin and an effusive origin. Incised valleys in most of the flanks of Apollinaris Patera indicates ash deposits and an explosive origin. On the west side (left), landslides that have shaped its surface also indicate ash deposits. Towards the south flank, a large fan of material flowed out of the volcano. This indicates an effusive origin. Perhaps during its early development Apollinaris Patera had an explosive origin with effusive eruptions taking place later on.

Ceraunius Tholus and Uranius Tholus Ceraunius Tholus (bottom) shows several incised valleys cut into its flanks which indicate that it was easily eroded and probably consists of ash deposits due to explosive activity. The lower flanks of the volcano have been buried beneath the plains material. Ceraunius Tholus is about the size of the Big Island of Hawaii. Uranius Tholus (Top) also shows similar characteristics to Ceraunius Tholus. A major impact crater, just above Ceranius Tholus, postdates the plains material and volcano. However, a prominent delta of probable volcanic material was emplaced within the impact crater at the mouth of a sinuous channel that extends up the flank of Cerauius Tholous to the summit crater.

Tharsis Tholus Tharsis Tholus measures about 150 kilometers (93 miles) across and 8 kilometers (5 miles) high. The east and west flanks are indented giving it a strange appearance. One possible cause for its appearance is that when the lava supply drained away, the center of the volcano collapsed. An alternative is that big slump areas carried off portions of the flanks, giving it the broken appearance.

Uranius Patera Uranius Patera is about the size of the Big Island of Hawaii. It is about 3 kilometers (1.9 miles) in height. It has shallow slopes and lava flows. This indicates an effusive origin. The center caldera was formed when lava drained away and the volcano collapsed.

Ulysses Patera This feature is an example of a class of volcanoes that are considerably smaller than the broad shield volcanoes. The summit consists of a single, very circular caldera with a smooth floor that predates the ejecta from two large impact craters. The lower flanks of the volcano, including portions of the impact craters, have been buried by the material that makes up the surrounding plains. This superpositional relationship indicates that the plains were emplaced subsequent to both the volcano and the large impact craters on the volcano. The plains are probably made up of lava supplied from Tharsis Montes that flowed down the sides of the broad uplift associated with the Tharsis shields. Both the plains and the volcano are cut by a graben, indicating tectonic activity subsequent to the emplacement of the plains.

Tyrrhena Patera Volcanoes located within the densely cratered southern highlands have a very different morphology from either the Tharsis or Elysium volcanoes. Tyrrhena Patera has very little vertical relief (< 2 kilometers), resulting in very shallow flank slopes. The flanks of the volcano are deeply eroded with many broad channels that radiate from the summit region. The low relief and easily erodible nature of the flank materials has been interpreted to indicate that the bulk of the volcano is composed of pyroclastic ash deposits. This interpretation implies that the style of eruption for the highland volcanoes like Tyrrhena Patera is significantly different from the repeated effusion of fluid lavas that built up the shield volcanoes.

Hadriaca Patera Much like Tyrrhena Patera, Hadriaca Patera is a deeply eroded feature having little vertical relief. Several impact craters are superimposed on the eroded flanks, indicating a great age for this volcano. A large channel has its source near the southeastern margin of the volcano; the fluid that carved the channel flowed southwest into the interior of the Hellas basin.

Tempe Volcano Volcanic construct on Mars are not all enormous mountains like the Tharsis Montes. This elongate hill surmounted by a linear depression is interpreted to be a product of localized but not extremely voluminous eruptions. If the volcanic material was emplaced by ejection along a ballistic trajectory, this feature may be similar to a terrestrial cinder cone. This feature is aligned with several grabens in the area so that a structural weakness in the crust may have provided the conduit for the volcanic material to reach the surface.

Hellas Mounds Numerous small mounds having summit craters are found in various locations on Mars. The mounds shown here are east of the Hellas basin. These features have been interpreted to be pseudocraters created by localized phreaticexplosions where lava interacts with volatile-rich ground. Most of the mounds are between 400 meters (1,312 feet) to 1 kilometer (.62 miles) across. Many have slotlike summit vents. However, images presently available do not have sufficient resolution to show conclusive evidence of a volcanic origin for the mounds. 


Mars wants water for terrestrial life and to function as a habital planet.  The confirmation that liquid water once flowed on Mars, the existence of nutrients, and the previous discovery of a past magnetic field that protected the planet from cosmic and solar radiation, together strongly suggest that Mars could have had the environmental factors to support life. After the Earth, Mars is the most habitable planet in our solar system. Its soil contains water to extract.  It isn’t too cold or too hot.  There is enough sunlight to use solar panels.  Gravity on Mars is 38% that of our Earth's, which is believed by many to be sufficient for the human body to adapt to.  It has an atmosphere (albeit a thin one) that offers protection from cosmic and the Sun's radiation
The day/night rhythm is very similar to ours here on Earth: a Mars day is 24 hours, 39 minutes and 35 seconds

The average Humans cannot live on Mars without the help of technology, but compared to other planets it's paradise!  There has been evidence of nitrogen oxgen and carbon present essential for life.   Maybe mars weather changes over the years there might be life? Using a spectometer on mars detected water based minerals. With technology today there will be more chances to explore mars or use technology for humans to acclimatize to mars. May be the iron on Mars can be used for something useful to help the planet?


© Copyright 2018 Shirley East. All rights reserved.

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