A new study claims that a mineral found in Mars' dust called ferrihydrite, which forms in the presence of cool water, is likely what gives the planet its reddish hue.

A new study in the journal Nature Communications reveals that Mars is red for very much the same reason it may have once been home to life — namely, that it was a wet planet. This is in line with research from last year that detailed how Mars was covered in bodies of water in its distant past.