Mars Planet

 Astronomy

   Mars

   Planet

  

   How far is Mars from Earth?

   What is the size of Mars?

   What do Mars and Earth have in common?

   What is the temperature on Mars?

   When did Viking 1 and Viking 2 land on Mars?

   Should humans inhabit space on Mars?

   Mars, the fourth planet in the solar system in terms of distance from the Sun, and the seventh planet in size and mass.  This is the most noticeable reddish thing in the night sky from time to time.

   Mars

   A particularly quiet view of Mars (Thrace Side), a collection of images taken in April 1999 by the Mars Global Surveyor spacecraft.  The dark mound surrounding the Arctic cap and the Vestatus borealis is visible in the upper part of the world.  Clouds of white water ice surround the most prominent volcanic peaks, including Olympus Mons near the western limbs, Alba Petra to its northeast, and the Thracian volcanic line to the southeast.  Near the equator east of the height of Thrace can be seen a huge gash marking the valley system Wallace Mariners.

   Sometimes called the Red Planet, Mars has long been associated with war and slaughter.  It is named after the Roman god of war.  Until 3,000 years ago, Babylonian astronomers called the planet Nergal their god of death and plague.  The two moons of the planet, Phobos (Greek: "fear") and Demos ("terror") were named after the two sons of Iris and Aphrodite (in Greek mythology the counterparts of Mars and Venus, respectively).

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   Planetary data for Mars

   * The planet needs more time to return to the same position in the sky than the sun, as seen from Earth.

   Average distance from the sun 227,943,824 km (1.5 AU)

   The eccentricity of the orbit is 0.093

   The tilt of the orbit is 1.85 طرف towards the lunar eclipse

   Year of Mars (Revolutionary Period) 686.98 Earth Days

   Visual Intensity Average Opposition at .02.01

   Mean synodic period * 779.94 Earth days

   The average orbital speed is 24.1 kilometers per second

   The radius of the equator is 3,396.2 km

   North Pole radius 3,376.2 km

   South Pole radius 3,382.6 km

   Surface area 1.44 × 108 km2

   Mass 6.417 x 1023 kg

   Average density 3.93 g / cm3

   Average surface gravity 371 cm / sec2

   Escape speed 5.03 km / s

   Duration of rotation (cidral day of Mars) 24 hours 37 minutes 22.663 seconds

   Mars means solar day (civil) 24 hours 39 minutes 36 seconds.

   Tilt the equator toward 25.2

   Average surface temperature 210 K (82 ° F, −63 ° C)

   Normal surface pressure 0.006 bar

   Number of known moons 2

   In recent times, Mars has attracted people for more important reasons than its blasphemous appearance.  This planet is the second closest to Earth after Venus and is usually easier to observe in the night sky because its orbit is outside the Earth.  It is also the only planet whose solid surface and atmospheric reflections can be seen through telescopes from Earth.  A centuries-long study by ground observers spread through spacecraft observations since the 1960s has revealed that Mars resembles Earth in many ways.  Like Earth, Mars has clouds, winds, about 24 hours a day, weather patterns, polar ice caps, volcanoes, valleys and other familiar features.  Interesting indications are that billions of years ago, Mars was much more like Earth than it is today, with dense, warm climates and abundant water - rivers, lakes, floodplains and perhaps oceans.  By all accounts, Mars is now a sterile, frozen desert.  However, close photographs of the black lines on the slopes of some of the crater during the spring and summer of Mars suggest that at least a small amount of water may flow seasonally over the planet's surface, and below the South Pole cap.  This is indicated by the radar reflection from a possible lake.  Water may still be present as a liquid in safe areas below the surface.  The presence of water on Mars is considered a major problem because life, as it is now understood, cannot exist without water.  If microscopic life forms ever appeared on Mars, there is still a long way to go before they can survive in these hidden waters.  In 1996, a team of scientists reported what they concluded as evidence of ancient microbial life in a piece of meteorite coming from Mars, but most scientists disagreed with their interpretation.  ۔

   Since at least the end of the 19th century, Mars has been considered the most hospitable place for both local life and human exploration and habitat in the extraterrestrial solar system.  At the time, speculation was rife that the so-called canals of Mars - the complex system of long, straight-line lines that very few astronomers claimed to have seen in telescopic observations - were the creation of intelligent creatures.  Climate change in the planet's appearance, which is attributed to vegetation spreading and retreating, has added to the evidence required for biological activity.  However, these canals later turned out to be deceptive, and climate change did not dampen public interest in the possibility of geographical, scientific, and the possibility of life on Mars and the planet, rather than biological.

   During the last century, Mars has gained a special place in popular culture.  From H. G. Wells and Edgar Rice Burroughs to Ray Bradbury in the 1950's and Kim Stanley Robinson in the 90's, Martin Canal's rise to prominence has been a movement for generations of fiction writers.  Mars has also been a central theme in radio, television, and film, perhaps the most infamous case being the radio play production of Orson Wales' HG Wales novel War of the World, which drew thousands of immature listeners on the evening of October 30, 1938.  Persuaded  Creatures from Mars were invading the earth.  The mysticism of the planet and many real mysteries continue to be the impetus for both scientific research and the human imagination.

  

   Learn about the Martian Revolution on Earth.

   Find out how long a year is on Mars.

  

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   Mars is the fourth planet to emerge from the sun.  It revolves around the sun at an average distance of 228 million kilometers (140 million miles), or about 1.5 times the distance of the earth from the sun.  Due to the relatively long orbit of Mars, the distance between Mars and the Sun ranges from 206.6 million to 249.2 million kilometers (128.4 million to 154.8 million miles).  Mars orbits the Sun once every 687 Earth days, which means its year is almost twice as long as Earth's.  At its closest point, Mars is less than 56 million kilometers (35 million miles) from Earth, but when the two planets are in opposite directions to the solar system, it is reduced to about 400 million kilometers (250 million miles).  Is.

   The easiest way to observe Mars is when it and the Sun are in opposite directions in the sky - that is, in the opposite direction - because it then rises high in the sky and shows a completely bright face.  Conflicts occur almost every 26 months.  Conflicts can occur in different places in the orbit of Mars.  The best things to see are when the planet is closest to the sun, and similarly to the earth, because Mars is then the brightest and largest.  Close opposition occurs almost every 15 years.

   Mars rotates on its axis once every 24 hours and 37 minutes, making a day on Mars a little longer than a day on Earth.  Its axis of rotation is about 25 ° inclined towards its orbital plane, and as far as the Earth is concerned, tilt gives rise to the seasons on Mars.  The year of Mars consists of 668.6 solar days of Mars called Souls.  Due to the elliptical orbit, southern temperatures are lower (154 on Mars) and warmer than northern (178 on Mars).  The situation is slowly changing, however, as 25,000 years from now, northern summers will be shorter and warmer.  In addition, the tilt of the axis, or tilt, is slowly changing over a time scale of about one million years.  Oblivion can occur near zero during the current period, when Mars has no weather, up to 45, when the climatic differences are extreme.  In 100 million years, obliqueness can reach up to 80%.

   Seasons of Mars

   Mars weather, the result of a 24.9 جھ tilt of the planet towards its orbital plane.  At this time, southern summer occurs when the long orbit of Mars brings it closer to the sun.  As the seasons change, the polar caps alternate and shrink.  At its maximum size, the southern cap extends approximately 5 times toward the equator than the northern cap.

  

   Mars is a small planet, only larger than Mercury and slightly larger than Earth.  It has an equatorial radius of 3,396 km (2,110 mi) and an average polar radius of 3,379 km (2,100 mi).  The mass of Mars is only one-tenth of the Earth's value, and its gravitational speed of 3.72 meters (12.2 feet) per second on the surface means that the objects on Mars weigh about one-third of their weight on Earth's surface.  There is more.  Mars has only 28% of the Earth's surface area, but because more than two-thirds of the Earth is covered by water, the Earth's surface area can be compared.  For additional orbital and physical data, see Table.

   Early telescopic observations

   Mars was a mystery to the ancient astronomers, who were amazed by its seemingly fascinating motion in the sky; sometimes in the direction of the sun and other celestial objects (direct, or progress, motion), sometimes in the opposite direction (  Opposite movement).  In 1609, the German astronomer Johannes Kepler, through his Danish colleague Tycho Bray, used the observations of the planet's high naked eye to experimentally estimate its laws of motion, and thus the modern gravitational theory of the solar system.  Paved the way for  Kepler found that the orbit of Mars is an ellipse with which the planet moves in unequal but predictable motion.  Earlier, astronomers based their views on the old Ptolemaic idea of ​​circular orbits and uniform motion classification.

   The earliest telescopic observations on Mars that showed the planet's disk were made in 1610 by the Italian astronomer Galileo.  In 1659, Huygens made a drawing of Mars showing a large black mark on the planet, now called Syrtis Major.  The polar caps of Mars were first noted in 1666 by the Italian-born French astronomer Gian Dominico Cassini.

   Visual observers later made many important discoveries.  The period of the planet's rotation was discovered by Haggins in 1659, and Cassini measured it in 24 hours and 40 minutes in 1666 - just 3 minutes by mistake.  The weak atmosphere of Mars was first noted by William Herschel, a British astronomer of German descent in the 1780s, who also measured the tilt of the planet's rotation axis and was the first to discuss the seasons on Mars.  In 1877, Asaf Hall of the US Naval Observatory discovered that Mars had two natural satellites.  Telescopic observations have also documented many meteorological and meteorological phenomena occurring on Mars, such as different types of clouds, increasing and contraction of polar caps, and seasonal changes in the color and extent of dark regions.

   The first known map of Mars was made in 1830 by Wilhelm Beer and Johann Heinrich von Mلdler of Germany.  Italian astronomer Giovanni Virginio Schiaparelli created the first modern astronomical map of Mars in 1877, which contained the basis of the name system that is still in use today.  The names on the map are in Latin and are based primarily on the ancient geography of the Mediterranean region.  For the first time, the map also showed signs of a straight line interconnected system over bright areas, which he described as canals (Italian: "channels").  Schiaparelli is usually credited with his first description, but his compatriot Petro Angelo Sichi developed the Canali theory in 1869.  In the late 19th century, American astronomer Percival Lowell set up an observatory in Flagstaff, Arizona, specifically to observe Mars, and produced it.  Extensive maps of the canals of Mars until his death in 1916.

   Mars as seen from Earth.

   For the Earth-based telescope observer, the surface of Mars outside the polar caps is characterized by bright red ocher-colored areas with visible black markings.  In the past, bright areas were called deserts, and the vast majority of dark areas were actually called Maria (Latin: "ocean" or "ocean"; single horse) in the idea that they were covered by water.  ۔  No topography can be seen with ground-based binoculars.  What is observed are changes in the brightness of the surface or changes in the opacity of the atmosphere.

   Mars: The last day of spring

   Mars (Certus Major Side) An image taken by the Hubble Space Telescope orbiting the Earth on March 10, 1997, the last day of the Martian spring in the Northern Hemisphere.  Long acquainted with telescopic observers.  The Arctic cap at the top has lost most of its annual frozen carbon dioxide layer, revealing a small permanent water cap and black collar sand dunes.  Syrtis Major is a large black mark just below the center and east.  Beneath it, on the southern limbs, is the gigantic Impact Basin Heels, which is covered by an elliptical portion of water ice clouds.  Clouds of water ice are also visible on the eastern limbs above the volcanic peaks in the Elysium area.

  

   Surface features

   Dark marks cover about one-third of the surface of Mars, mostly in a band between latitudes 10 ° and 40 ° S around the planet.  Their distribution is irregular, and their overall pattern has been seen to change from tens to hundreds of times.  The Northern Hemisphere has only three major features of this year; Oxedilia planetia, Certus Major, and a deep collar around the pole - which were once considered shallow seas or vegetation areas.  It is now known that many dark regions of Mars form and change when winds move black sand around the surface or shake dusty areas.  Many bright areas are dusty areas.  The canals that are so prominent on telescopic observations around the early 20th century are not visible in close-up images of the spacecraft.  They were almost certainly imaginary features that observers thought pushed their telescopes to create objects close to the resolution limit.  Other features, such as "wave of darkness" and "blue haze" described by early observers on the telescope, are now known to result from a combination of changes in viewing conditions and surface reflective properties.

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   Polar region

   For telescopic observers, the most amazing regular changes on Mars are at the poles.  With the onset of fall in a particular hemisphere, clouds form over the corresponding polar region, and a cap made of frozen carbon dioxide begins to grow.  In the north, the small cap eventually extends to 55 ° latitude, and in the south to the large 50 ° latitude.  Hats off in the spring.  During the summer, the North Carbon Dioxide cap disappears completely, leaving only a small cap of water ice.  In the south a small residual cap composed of carbon dioxide ice and water ice stays in the summer.

   Mars Polar Water Ice Cap

   Mars permanent polar water ice cap, in two views obtained by the Global Surveyor of Mars in addition to one Mars summer in the northern summer (March 1999, left and January 2001, right).  The ringing of the bell, measuring about 1,100 kilometers (680 miles), is the dark sand dunes that mark the northern part of the Vestitus Borealis.  The distinctive appearance of the hat reflects the spiral patterns of scorpions and valleys in the underground regions.  The difference in the coverage of summer frosts can be seen by comparing the images.  Although they may appear small, they indicate large annual changes in the summer budget for the polar cap.

  

   The design of seasonal polar hats has been the subject of debate for almost 200 years.  An early hypothesis - that the hats were made of water ice - can be traced back to the English astronomer William Herschel, who assumed that they existed on Earth.  In 1898, George J. Stony, an Irish scientist, questioned this theory and suggested that caps may contain frozen carbon dioxide, but Dutch American astronomer Gerard Kuiper's 1947 discovery of carbon dioxide in the atmosphere.  Until then, there was no evidence to support this view.

   In 1966, American scientists Robert Layton and Bruce Murray published the results of a numerical model of the thermal atmosphere on Mars, which raised a lot of doubts about the hypothesis of water ice.  Their calculations indicated that, under the conditions of Mars, carbon dioxide would accumulate at poles in the atmosphere, and their model of carbon dioxide caps evolved and shrunk, mimicking the observed behavior of the original caps.  The model predicted that seasonal hats were relatively thin, only a few meters deep near the poles and thinner towards the equator.  Although based on the ease of real conditions on Mars, their results were later confirmed by thermal and spectral measurements taken by the twin Mariner 6 and 7 spacecraft when they flew from Mars in 1969.

   Manifestations of a temporary environment

   Early telescopic observers noted instances in which the surface features of Mars were temporarily unclear.  They observed both white and yellow opacity, which were correctly explained by the thick gas and dust, respectively.  Binocular observers also noted the intermittent disappearance of all black markings, usually around southern summer.  Once again, they were interpreted correctly as a result of global dust storms.  Observations of the spacecraft have confirmed that haze, clouds and fog usually cover the surface.

   Mars: Storm

   Large hurricane system at altitude above the Arctic region of Mars, photographed by the Mars Global Surveyor on June 30, 1999.  The "curl" consists mainly of water ice clouds that meet the orange-brown dust rising from the surface with strong winds.  The North Pole cap is seen on the upper left as a spiral pattern of light and deep bands.