Mars

Mars - Rotating Model
Credit: Almond/NASA

Mars is the fourth planet out from the Sun. Sometimes called the Red Planet, it gets its colour from its rusty red rocks and soil. It has two tiny moons called Phobos and Deimos.

Mars has an atmosphere that is much thinner (less dense) than that on Earth. It is primarily made up of Carbon Dioxide (95%) and Nitrogen (3%) gases. Because of its smaller size and mass, the surface gravity on Mars is around 40% of that on Earth.

The surface appears to change from winter to summer. Many years ago, this was thought to be evidence for plants and other life, but it is now known to be enormous dust storms that rage across most of the planet.

Since the arrival of Mariner 4 back in 1964, lots of spacecraft have been to Mars, and some, like the Mars Rover missions in 2003, have even landed on the surface.

Planet Data Sheet show »

Facts and Figures	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune
Orbital Distance (AU)¹	0.38	0.72	1.0	1.52	5.2	9.45	19.2	30.06
Radius (KM)	2,440	6,052	6,378	3,397	71,492	60,268	25,559	24,746
Mass (Earth Masses)²	0.055	0.82	1.0	0.11	318	95.2	14.5	17.1
Year Length (Earth Days)	88	225	365.25	687	11.9 Years	29.45 Years	84.0 Years	164.8 Years
Day Length (Earth Days)	176	117	1.0	1.03	0.41	0.43	0.75	0.67
Surface Gravity (g)³	0.38	0.91	1.0	0.38	2.34	0.93	0.92	1.12
Surface Temperature	-200 to 400 °C	460 °C	-80 to 50 °C	-150 to 20 °C	-110 °C	-140 °C	-190 °C	-200 °C
Number of moons	0	0	1	2	63	60	27	13

Notes: ¹ 1 AU (or Astronomical Unit) = 149,600,000 KM and is the mean distance from the Earth to the Sun
² 1 Earth Mass = 5,980,000,000,000,000,000,000,000 KG : ³ 1 g = 9.8 m/s²

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