The green spots that are visible in the new image are also found in red rocks on Earth. They are formed when liquid water seeps through sediment before hardening into rock. Sign up for Chip Chick ...

and greenish spots in the rock, intriguing scientists. On Earth, green spots in red rocks sometimes develop due to microbial activity or decaying organic matter that facilitates iron reduction ...

On Earth, similar green spots are often observed in ancient "red beds" and are typically formed by chemical reactions where ...