T he story of the red planet, it turns out, may be due for a revision. At one time, experts thought that Mars was covered ...

Mars is a dry, rocky, cold, and dusty planet. Its dust is the key to its iconic red color. Now, scientists say there’s more to the story ( Credit: NASA/JPL/USGS ) ...

Graphic showing how Mars turned from a grey, wet planet into a dusty red planet. From left to right, four steps are illustrated in a single image. First, iron in the planet’s rocks react with oxygen ...