Facts About Mars
Published September 16, 2026 · FactsSeeker
Mars is a rocky world with polar ice, giant volcanoes, and evidence of a wetter past.
Rust gives it a reddish appearance
Iron minerals in surface material oxidize, producing the familiar red color. [1]
It has two small moons
Phobos and Deimos orbit Mars. Both are irregularly shaped rather than round like Earth’s Moon. [1]
Its atmosphere is thin
Most Martian air is carbon dioxide. Surface pressure is far lower than on Earth. [1]
A day is similar to Earth’s
A Martian day lasts slightly longer than twenty-four hours. A Martian year lasts much longer than an Earth year. [1]
Olympus Mons is enormous
Mars contains the solar system’s tallest volcano. Its broad shape reflects repeated volcanic activity. [1]
Water left geological evidence
Ancient channels, minerals, and deposits indicate a wetter past. That does not establish that life once existed there. [1]
A year lasts nearly two Earth years
Mars takes about 687 Earth days to orbit the Sun. Its greater distance makes the journey longer than Earth’s. [1]
Mars has seasons
Its tilted axis produces seasonal changes. Each season lasts longer than the corresponding season on Earth. [1]
A vast canyon system crosses the surface
Valles Marineris stretches for thousands of kilometers. Its scale greatly exceeds that of Earth’s Grand Canyon. [1]
Carbon dioxide dominates the atmosphere
The Martian atmosphere contains mostly carbon dioxide, with nitrogen and argon. It cannot support unprotected human breathing. [1]
Polar caps contain different kinds of ice
Mars has both water ice and frozen carbon dioxide near its poles. Seasonal changes alter the ice cover. [1]
Ancient magnetism remains in rocks
Mars lacks a global magnetic field today. Magnetized crustal areas preserve evidence of a different magnetic past. [1]
Sources & further reading
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Sources checked 2026-09-16. Our approach to facts · Suggest a correction