Mars
The rusty desert world
Mars is a cold, dusty world where iron-rich minerals give the surface its characteristic red color. Ancient river valleys, dry lake beds, and polar ice deposits suggest that liquid water once flowed on its surface.
Read the full Mars guideFacts, distance from Earth and the Sun, temperature, moons, water, surface, atmosphere, rovers, and the search for life on the Red Planet.Drag to rotate
Key facts
- Diameter
- 6,779 km
- Radius
- 3,389.5 km
- Mass
- 6.417e+23 kg
- Gravity (Earth = 1)
- 0.377
- Density
- 3.9335 g/cm³
- Distance from Sun
- 227,900,000 km
- Orbital period
- 687 Earth days
- Rotation period
- 24.62 hours
- Average temperature
- -63°C
- Known moons
- 2
Values are approximate and based on cited sources.
Atmosphere
- Carbon dioxide
- Nitrogen
- Argon
Surface
Dusty red plains, canyons such as Valles Marineris, and the enormous volcano Olympus Mons.
Internal structure
A partly molten iron core, silicate mantle, and thin basaltic crust.
Moons
Phobos
Its extremely low orbit will one day cause it to break apart or crash into Mars.
Deimos
One of the smallest known moons in the solar system.
Exploration missions
Perseverance Rover
The first Mars rover designed to collect and cache carefully documented samples for possible return to Earth.
View missionViking Program
The first fully successful U.S. mission to land and operate on Mars and the first designed to search for life there.
View missionCuriosity Rover
A car-size Mars laboratory studying whether Gale Crater ever offered habitable conditions.
View mission
Sources
- NASA Science — Mars— last verified 2026-01-15