686.971 Earth days
1.8808 Earth years
668.5991 sols
Distance from Sun:
1.52 AU
1.850° to ecliptic
5.65° to Sun's equator
1.67° to invariable plane
6,787 km
0.37628 G (1/6 of Earth normal
  • Basalt (primarily)
  • Magnesium
  • Sodium
  • Potassium
  • and Chloride

Mars is a terrestrial planet, and is the fourth planet from the Sun.


The high amounts of iron in its soil causes a red-orange color, which is why it is known as "the red planet". In Roman mythology, Mars was the god of war (taken from Greek mythology, Ares, the god of war) it is thought that the planet received this god's name because of its red color. All investigations of Mars, either with telescopes or with exploration craft came to the same result: Mars is a Barren wasteland, marked by craters, vast dune fields littered with rock outcroppings, and perhaps the largest known volcanoes in the solar system. At the moment the presence of life on mars is unknown though growing evidence suggests a lack of, at the least in present times. not even in its basic form (single celled organisms). However there is evidence that The conditions for life existed on Mars during its formation and early years, when the atmosphere, allowed for by a active magnetosphere was thick enough to allow for liquid water, and perhaps life to survive, now the atmosphere is thinned out (currently about 1% of the pressure on Earth). Today life cannot exist on the surface because that Mars does not have a protective magnetic field to protect against: solar radiation, asteroids, and other stellar particles, this would hinder lifeforms on mars. And the atmosphere is too thin to allow for permanent bodies of liquid water.

Looking for water

Liquid water on Mars cannot exist permanently, as the atmospheric pressure on mars is too low to keep liquid, and exposed ice from evaporating. However liquid water had been observed on mars on occasion, usually evaporating not long after leaking from the martian surface. Mars does, however, have two permanent ice caps; composed of frozen Co2 and water ice on both poles. During the martian summers, some ice sublimates bringing small amounts of water vapor across the northern, and southern hemispheres; along with dust in summer winds. Another reason for lack of life is low temperatures, pressures and no surface water. Surface water is the main ingredient to life, but with so low temperatures (-60°C average) and pressures (1/6 of average Earth pressure), the water is now locked away underground and in the polar ice caps. Away from the caps, water is only present as clouds and fog, but for a short time. As the lack of a magnetic sphere allows solar wind to strip away The Martian atmosphere. The Martian atmosphere is made of frozen CO² gas that is thinner than the Armstrong limit, thus making breathing on mars impossible, while the atmosphere of Venus is mostly CO², but it is mixed with sulfur, creating a powerful greenhouse effect which dramatically heats up the planet. Because of these factors, there only chance of single cell life.

Since 1960, there have been almost forty attempted orbiters and landers sent to Mars. Out of all these, only sixteen where partially, or completely successful. Currently, there are three rovers and three orbiters on Mars. These devices have been sent off on different dates, ranging from April 7, 2001, to as recently as the Mars Science Laboratory rover that was launched on November 26, 2011 and still has not arrived on Mars. Future plans include the launching of the MAVEN (Mars Atmospheric and Volatile Evolution) and several other proposed devices that have not yet been approved.

A day on Mars lasts almost the same as on Earth (slightly more than 24h for one full rotation). Mars has two Natural Satellites: Phobos and Deimos, asteroids captured by mars during the formation of the solar system, both are named after the Greek mythological representations of Fear and Terror.

 The Solar System v·d·e 
Solar System XXVII
The Sun · Mercury · Venus · Earth · Mars · Ceres* · Jupiter · Saturn · Uranus · Neptune · Pluto* · Eris* · Sedna*
Planets · Dwarf planets · Moons: Terran · Martian · Asteroidal · Jovian · Saturnian · Uranian · Neptunian · Plutonian · Eridian
Pluto' * Ceres * Eris * Haumea * Makemake
Small bodies:   Meteoroids · Asteroids (Asteroid belt) · Centaurs · TNOs (Kuiper belt/Scattered disc) · Comets (Oort cloud)
planets with '*' are dwarf's but listed between 'real planets'.
See also astronomical objects and the solar system's list of objects, sorted by radius or mass.
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