The Chinese rover “Zhuzhong” has found evidence that water remained on Mars in liquid form much longer than previously thought. It is believed that Mars was wet at least 3 billion years ago — during the so—called Hesperian period, named after the Hesperides plateau – and later became dry and cold.
The data obtained by the rover suggests that there was water in the Utopia basin at a time when it should have already been dry and cold.