There is an ocean under Mars.

Two separate teams reading NASA’s InSight seismic data found it. In 2024, the first team found liquid water trapped in fractured rock 11.5 to 20 kilometers down. Enough to cover the whole planet 1 to 2 kilometers deep.

In 2025, a second team found a shallower layer at 5.4 to 8 kilometers. Another 500 to 780 meters of global ocean, sitting in rock pores.

Mars didn’t lose its water to space. It sank. Pressure and heat keep it liquid down there. Unreachable with today’s drilling technology, but real.

The top 5 kilometers of Martian crust appear dry. Below that, the rock is soaked. The discovery also marks another promising place to look for life, if the reservoir can ever be reached.