A large reservoir of water has been discovered on Mars.
The Mars InSight Lander, which landed on the Red Planet in 2018, had a seismometer which recorded four years of vibrations from within the planet.
Analysis of the data has made scientists believe that there are large reservoirs of water deep within the Martian crust.
Frozen water is present at the Martian poles and water vapour has been detected in the atmosphere. This is the first time that a possible source of liquid water has been identified.
It is believed that in the past, Mars used to be a wet planet, similar to Earth, but it has been a desert for the past three billion years.
Scientists have long speculated that there could be life on Mars, with the most likely environments now being deep underground, close to the liquid water.