Scientists were shocked to see the marks made by the lander's airbags scraping across the surface.

They expected the ground to crack or break but instead it rumpled up and folded, as if it was wet.

This means there might be liquid water on - or just below - Mars' surface, which could mean that at one time lakes and oceans existed there.

And if water is found in the soil on Mars then the chances of finding life on there is massively increased.

Very salty water

Scientists think that if water does exist there it would have to be very salty to stop it from freezing or evaporating.