Mars
The Red Planet — Next Frontier
Mars is the most explored planet beyond Earth. Its red color comes from iron oxide (rust) in its soil. Mars hosts Olympus Mons, the tallest volcano in the solar system at 21.9 km, and Valles Marineris, a canyon system stretching 4,000 km. Evidence of ancient river beds suggests Mars once had liquid water. NASA and ISRO both have active missions studying Mars.
Mass
6.42 × 10²³
kg
Diameter
6,779
km
Gravity
3.72
m/s²
Temperature
-65
°C avg
Day Length
24.6
hours
Year Length
687
Earth days
Distance from Sun
227.9
M km
Atmosphere
95% CO₂, 2.7% N₂ — thin, 0.6% Earth pressure
Moons(2)
Phobos
Orbits Mars in just 7.6 hours — rising in the west and setting in the east. It's slowly spiraling inward and will crash into Mars in ~50 million years.
Deimos
The smaller of Mars's two moons. So small that its escape velocity is only 20 km/h — you could throw a ball into orbit.