Geography and naming of surface features Mars

1 geography , naming of surface features

1.1 map of quadrangles
1.2 impact topography
1.3 volcanoes
1.4 tectonic sites
1.5 holes

geography , naming of surface features




a mola-based topographic map showing highlands (red , orange) dominating southern hemisphere of mars, lowlands (blue) northern. volcanic plateaus delimit regions of northern plains, whereas highlands punctuated several large impact basins.



these new impact craters on mars occurred sometime between 2008 , 2014, detected orbit

although better remembered mapping moon, johann heinrich mädler , wilhelm beer first areographers . began establishing of mars s surface features permanent , more precisely determining planet s rotation period. in 1840, mädler combined ten years of observations , drew first map of mars. rather giving names various markings, beer , mädler designated them letters; meridian bay (sinus meridiani) feature .

today, features on mars named variety of sources. albedo features named classical mythology. craters larger 60 km named deceased scientists , writers , others have contributed study of mars. craters smaller 60 km named towns , villages of world populations of less 100,000. large valleys named word mars or star in various languages; small valleys named rivers.

large albedo features retain many of older names, updated reflect new knowledge of nature of features. example, nix olympica (the snows of olympus) has become olympus mons (mount olympus). surface of mars seen earth divided 2 kinds of areas, differing albedo. paler plains covered dust , sand rich in reddish iron oxides once thought of martian continents , given names arabia terra (land of arabia) or amazonis planitia (amazonian plain). dark features thought seas, hence names mare erythraeum, mare sirenum , aurorae sinus. largest dark feature seen earth syrtis major planum. permanent northern polar ice cap named planum boreum, whereas southern cap called planum australe.

mars s equator defined rotation, location of prime meridian specified, earth s (at greenwich), choice of arbitrary point; mädler , beer selected line first maps of mars in 1830. after spacecraft mariner 9 provided extensive imagery of mars in 1972, small crater (later called airy-0), located in sinus meridiani ( middle bay or meridian bay ), chosen definition of 0.0° longitude coincide original selection.

because mars has no oceans , hence no sea level , zero-elevation surface had selected reference level; called areoid of mars, analogous terrestrial geoid. 0 altitude defined height @ there 610.5 pa (6.105 mbar) of atmospheric pressure. pressure corresponds triple point of water, , 0.6% of sea level surface pressure on earth (0.006 atm). in practice, today surface defined directly satellite gravity measurements.

map of quadrangles

for mapping purposes, united states geological survey divides surface of mars thirty quadrangles , each named prominent physiographic feature within quadrangle. quadrangles can seen , explored via interactive image map below.

the thirty cartographic quadrangles of mars, defined united states geological survey. quadrangles numbered prefix mc mars chart. click on quadrangle name link , taken corresponding article. north @ top; 0°n 180°w / 0°n 180°w / 0; -180 @ far left on equator. map images taken mars global surveyor.






impact topography

bonneville crater , spirit rover s lander

the dichotomy of martian topography striking: northern plains flattened lava flows contrast southern highlands, pitted , cratered ancient impacts. research in 2008 has presented evidence regarding theory proposed in 1980 postulating that, 4 billion years ago, northern hemisphere of mars struck object one-tenth two-thirds size of earth s moon. if validated, make northern hemisphere of mars site of impact crater 10,600 8,500 km (6,600 5,300 mi) in size, or area of europe, asia, , australia combined, surpassing south pole–aitken basin largest impact crater in solar system.

fresh asteroid impact on mars @ 3°20′n 219°23′e / 3.34°n 219.38°e / 3.34; 219.38. these before , after images of same site taken on martian afternoons of march 27 , 28, 2012 respectively (mro)

mars scarred number of impact craters: total of 43,000 craters diameter of 5 km (3.1 mi) or greater have been found. largest confirmed of these hellas impact basin, light albedo feature visible earth. due smaller mass of mars, probability of object colliding planet half of earth. mars located closer asteroid belt, has increased chance of being struck materials source. mars more struck short-period comets, i.e., lie within orbit of jupiter. in spite of this, there far fewer craters on mars compared moon, because atmosphere of mars provides protection against small meteors , surface modifying processes have erased craters.

martian craters can have morphology suggests ground became wet after meteor impacted.

volcanoes

viking 1 image of olympus mons. volcano , related terrain approximately 550 km (340 mi) across.

the shield volcano olympus mons (mount olympus) extinct volcano in vast upland region tharsis, contains several other large volcanoes. olympus mons 3 times height of mount everest, in comparison stands @ on 8.8 km (5.5 mi). either tallest or second-tallest mountain in solar system, depending on how measured, various sources giving figures ranging 21 27 km (13 17 mi) high.

tectonic sites

valles marineris (2001 mars odyssey)

the large canyon, valles marineris (latin mariner valleys , known agathadaemon in old canal maps), has length of 4,000 km (2,500 mi) , depth of 7 km (4.3 mi). length of valles marineris equivalent length of europe , extends across one-fifth circumference of mars. comparison, grand canyon on earth 446 km (277 mi) long , 2 km (1.2 mi) deep. valles marineris formed due swelling of tharsis area, caused crust in area of valles marineris collapse. in 2012, proposed valles marineris not graben, plate boundary 150 km (93 mi) of transverse motion has occurred, making mars planet possibly two-tectonic plate arrangement.

holes

images thermal emission imaging system (themis) aboard nasa s mars odyssey orbiter have revealed 7 possible cave entrances on flanks of volcano arsia mons. caves, named after loved ones of discoverers, collectively known 7 sisters . cave entrances measure 100 252 m (328 827 ft) wide , estimated @ least 73 96 m (240 315 ft) deep. because light not reach floor of of caves, possible extend deeper these lower estimates , widen below surface. dena exception; floor visible , measured 130 m (430 ft) deep. interiors of these caverns may protected micrometeoroids, uv radiation, solar flares , high energy particles bombard planet s surface.