Learn about the layers and features of Mars, the Red Planet, and how they affect its climate and habitability. Find out what elements and minerals make up its surface, interior and atmosphere, and how they compare to Earth's.

Learn about Mars' namesake, potential for life, size, orbit, moons, rings, formation, structure, surface, and atmosphere. See images and videos of the Red Planet and its exploration by NASA missions.

Learn about the main gases, isotopes, and water vapor in Mars's thin and cold atmosphere, and how they vary with season and location. Find out how Mars lost most of its atmosphere and water to space over time.

Mars, fourth planet in the solar system in order of distance from the Sun and seventh in size and mass. It is a periodically conspicuous reddish object in the night sky. Mars is designated by the symbol ♂.

Mars has a thin atmosphere made up mostly of carbon dioxide, nitrogen, and argon gases. To our eyes, the sky would be hazy and red because of suspended dust instead of the familiar blue tint we see on Earth. Mars' sparse atmosphere doesn't offer much protection from impacts by such objects as meteorites, asteroids, and comets.

Information on the composition of the crust of Mars has been obtained from Earth-based 2 and orbital spectra 3, 4, 5, 6, in situ spectral and chemical observations from the Viking and...

Learn about the vertical structure, composition, and circulation of the Martian atmosphere, which is mostly carbon dioxide and dust. Find out how the atmosphere responds to solar radiation, temperature, and seasonal changes on the red planet.

A comprehensive table of physical and orbital parameters of Mars, such as mass, radius, density, gravity, albedo, temperature, and atmosphere. Compare Mars with Earth and see the latest data from Viking 1 Lander.

The Mars InSight lander measured marsquakes and used them to map the crust, mantle, and core of the red planet. The results show that Mars has a thick crust, a single mantle layer, and a large, low-density liquid core.