Historical observations Mars

1 historical observations

1.1 ancient , medieval observations
1.2 martian canals
1.3 spacecraft visitation

historical observations

in 2005, radar data revealed presence of large quantities of water ice @ poles , @ mid-latitudes. mars rover spirit sampled chemical compounds containing water molecules in march 2007. phoenix lander directly sampled water ice in shallow martian soil on july 31, 2008. on september 28, 2015, nasa announced presence of briny flowing salt water on martian surface.

the history of observations of mars marked oppositions of mars, when planet closest earth , hence visible, occur every couple of years. more notable perihelic oppositions of mars, occur every 15 or 17 years , distinguished because mars close perihelion, making closer earth.

ancient , medieval observations

the ancient sumerians believed mars nergal, god of war , plague. during sumerian times, nergal minor deity of little significance, but, during later times, main cult center city of nineveh. in mesopotamian texts, mars referred star of judgement of fate of dead . existence of mars wandering object in night sky recorded ancient egyptian astronomers and, 1534 bce, familiar retrograde motion of planet. period of neo-babylonian empire, babylonian astronomers making regular records of positions of planets , systematic observations of behavior. mars, knew planet made 37 synodic periods, or 42 circuits of zodiac, every 79 years. invented arithmetic methods making minor corrections predicted positions of planets.

in fourth century bce, aristotle noted mars disappeared behind moon during occultation, indicating planet farther away. ptolemy, greek living in alexandria, attempted address problem of orbital motion of mars. ptolemy s model , collective work on astronomy presented in multi-volume collection almagest, became authoritative treatise on western astronomy next fourteen centuries. literature ancient china confirms mars known chinese astronomers no later fourth century bce. in fifth century ce, indian astronomical text surya siddhanta estimated diameter of mars. in east asian cultures, mars traditionally referred fire star (火星), based on 5 elements.

during seventeenth century, tycho brahe measured diurnal parallax of mars johannes kepler used make preliminary calculation of relative distance planet. when telescope became available, diurnal parallax of mars again measured in effort determine sun-earth distance. first performed giovanni domenico cassini in 1672. parallax measurements hampered quality of instruments. occultation of mars venus observed of october 13, 1590, seen michael maestlin @ heidelberg. in 1610, mars viewed galileo galilei, first see via telescope. first person draw map of mars displayed terrain features dutch astronomer christiaan huygens.

martian canals

by 19th century, resolution of telescopes reached level sufficient surface features identified. perihelic opposition of mars occurred on september 5, 1877. in year, italian astronomer giovanni schiaparelli used 22 cm (8.7 in) telescope in milan produce first detailed map of mars. these maps notably contained features called canali, later shown optical illusion. these canali supposedly long, straight lines on surface of mars, gave names of famous rivers on earth. term, means channels or grooves , popularly mistranslated in english canals .

influenced observations, orientalist percival lowell founded observatory had 30 , 45 cm (12 , 18 in) telescopes. observatory used exploration of mars during last opportunity in 1894 , following less favorable oppositions. published several books on mars , life on planet, had great influence on public. canali independently found other astronomers, henri joseph perrotin , louis thollon in nice, using 1 of largest telescopes of time.

the seasonal changes (consisting of diminishing of polar caps , dark areas formed during martian summer) in combination canals led speculation life on mars, , long-held belief mars contained vast seas , vegetation. telescope never reached resolution required give proof speculations. bigger telescopes used, fewer long, straight canali observed. during observation in 1909 flammarion 84 cm (33 in) telescope, irregular patterns observed, no canali seen.

even in 1960s articles published on martian biology, putting aside explanations other life seasonal changes on mars. detailed scenarios metabolism , chemical cycles functional ecosystem have been published.

spacecraft visitation

once spacecraft visited planet during nasa s mariner missions in 1960s , 70s, these concepts radically broken. results of viking life-detection experiments aided intermission in hypothesis of hostile, dead planet accepted.

mariner 9 , viking allowed better maps of mars made using data these missions, , major leap forward mars global surveyor mission, launched in 1996 , operated until late 2006, allowed complete, extremely detailed maps of martian topography, magnetic field , surface minerals obtained. these maps available online; example, @ google mars. mars reconnaissance orbiter , mars express continued exploring new instruments, , supporting lander missions. nasa provides 2 online tools: mars trek, provides visualizations of planet using data 50 years of exploration, , experience curiosity, simulates traveling on mars in 3-d curiosity.