♂Mars
The blazing "Red Planet." Home to the Solar System's tallest volcano and deepest canyon, and humanity's next destination.
- Distance from Sun
- 1.52 AU (about 227.9 million km)
- Diameter
- 6,779 km (0.53× Earth)
- Orbital period
- 687 days
- Rotation period
- 24.6 hours
- Moons
- 2 (Phobos, Deimos)
Science
The scienceMars looks red because of the iron oxide (rust) on its surface, earning it the name "the Red Planet." It boasts the tallest volcano in the Solar System, Olympus Mons (about 22 km high, 2.5 times Everest), and the longest canyon, Valles Marineris (about 4,000 km long). Cold and dry today, its dried-up riverbeds and river-delta deposits reveal that rivers and lakes once flowed there, making it the focus of missions searching for signs of life. Its two moons, Phobos and Deimos, mean "fear" and "rout" in Greek.
Name & Myth
The story behind the nameBecause it shines a blood-red color, Mars was given in the West the name of the god of war (the Greek Ares). And so its two moons were named for Fear and Rout, the companions that follow the war god. In East Asia, its red glow and seemingly irregular motion led it to be called "Hyeong-hok-seong," "the bright, bewitching star that leads people astray," and it was regarded as an ill omen. Matched to Fire among the Five Elements, it was called "Hwa-seong," the Fire Star.