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The Red Planet

Fourth Planet of the Solar System

Proper NameMars
Orbital Period687 days
Mean Distance from the Sun227.9 million km
1.52 AU
Rotation Period24.6 hours
Diameter6,794 km
Mean Surface Temperature-53°C
MoonsDeimos, Phobos
NotesThe fourth major planet from the Sun, Mars is distinctive for its red-orange colouration, broken only by icy white at the poles. Its diameter is only about half that of Earth.
The Martian North Pole

The broken and icy north polar region of Mars. Prominent against the whiteness is the dark gouge of the Chasma Boreale, the North Canyon.

The cold desert world of Mars lies further from the Sun than Earth. Considerably smaller than our own planet, Mars' atmosphere consists mainly of carbon dioxide.

Size Comparison of Mars

Mars has a diameter a little more than half that of Earth. Nonetheless, because it has no oceans, its total land surface is similar to that of our own planet.

The Valles Marineris

A view down into the Valles Marineris, an immense complex of valleys more than 4,000 kilometres in length, running between the volcanic plains of Tharsis and the densely cratered landscape of Chryse.

Map of Mars' western hemisphere
Map of Mars' eastern hemisphere

Key features on the western (top) and eastern (bottom) hemispheres of Mars.

Mars and its moons, Phobos and Deimos, shown to scale.


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