Why Is Mars Red?
Mars is red now, but it may have looked like charcoal in the past. CREDIT: NASA/ESA/Hubble Team
Expect to see a lot of red-orange landscapes over the next few weeks, as the Curiosity rover beams back its first photos of the rugged Martian scenery. But why is Mars red, anyway?
The simple explanation for the Red Planet’s color is that its regolith, or surface material, contains lots of iron oxide — the same compound that gives blood and rust their hue. But why does Mars have so much iron, why is that iron “oxidized,” and why does iron oxide look red?