Astro Quiz 5: Mars, the Red Planet
Question #5 – Why is Mars called the Red Planet?
Answer: The soil and rocks on the surface of Mars contain iron. Over time, winds and erosion on Mars have caused oxygen to combine with the iron creating iron oxide or, as it is commonly called, rust.
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Mars appears as a red-orange globe with darker blotches and white ice caps visible on both of its poles. Image credit: ESA