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Mars is the first planet outside the Earth's orbit, with a year 1.88 Earth years long. It has a very thin carbon dioxide atmosphere, and a mean surface temperature of a chilly -63°C.

    Vital statistics:
  • Mass: 6.4 x 1023 kg = 0.107 Earths/8.8 Moons
  • Diameter: 6779 km = 0.53 Earth's
  • Density: 3.93 tonnes/m3 = 0.713 Earth's density
  • Surface gravity: 3.7 m/s2 = 0.38g
  • Distance from Sun: 207 - 249 million km (227.9 Mkm semi-major axis) = 1.38 - 1.67 AU (Earth-Sun distances)
  • Period of orbit: 687.0 Earth days / 1.88 Julian years
  • Period of rotation: 1.03 Earth days (24.62 h)
  • No. of moons: 2
  • Atmosphere: 0.64 kPa (0.63% Earth's atmosphere), 96.0% CO2, 1.9% argon, 1.9% nitrogen, 0.15% O2, and trace gases, including 210 ppm (parts per million) water vapour.


Mars has two natural satellites, the small moons Phobos and Deimos.

Phobos, moon of Mars
Phobos, moon of Mars

Content © All rights reserved. Created : October 25, 2015 Last updated :December 27, 2015

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Great Scientists

Johann(III) Bernoulli

1744 - 1807

Johann Bernoulli (III) lived and worked in Berlin, where he was director of the Mathematics Department of the Academy of Berlin, and the last noted mathematician of the Bernoulli dynasty of mathematicians.

Johann Bernoulli (III), 1744 - 1807

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