The two robots, working alone and far apart from one another, are struggling on their respective treks along the Red Planet's rough terrain.

NASA's Perseverance rover found strange green spots in Martian rock, potentially indicating a past interaction with liquid water.

Nasa has found shocking “green spots” on Mars. On Earth, those spots can be a mark of the activity of microbes. Nasa cautioned that there is nothing to indicate the same is happening on Mars – but noted that it was an interesting and unexpected feature in the rock that could be an important find on the planet.