Mars

Mars is the fourth planet from the Sun, and is the seventh largest planet in the Solar System. Although its size and atmosphere are very different, many of its geographical features are similar to Earth's.

Fast Facts

1. Discovered in ancient times
2. First observed through a telescope by Galileo in 1610
3. Earth has launched 38 missions to explore Mars¹
4. Most recent mission: NASA's Mars Phoenix Lander
5. Radius: 3,397 kilometers (53% of Earth's radius)
6. Circumference: 21,344 kilometers
7. Surface area: 144.1 million square kilometers (28% of Earth's)
8. Mass: 6.4185x10²³ kilograms (11% of Earth's)
9. Average distance from the Sun: 227.9 million kilometers
10. 2 moons: Phobos and Deimos²
11. Atmospheric Content:
    1. Carbon Dioxide: 95.32%
    2. Nitrogen: 2.7%
    3. Argon: 1.6%
    4. Oxygen: 0.13%
    5. Carbon Monoxide: 0.008%
    6. Trace amounts of Water, Nitrogen Oxide, Neon, Hydrogen-Deuterium Oxygen, Krypton, Xenon

Family Resemblance

Photos sent by the Mars Phoenix Lander and other past missions have revealed that the geography of Mars is similar to Earth's. Many features resemble riverbeds, gullies, and flood plains.³

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