More than three billion years ago, the surface of Mars was flooded with liquid water on a periodic basis. The exact location of these flows remains a mystery, as they may have evaporated, become trapped in minerals, seeped underground, or been preserved in ice caps. In order to find out, American scientists analyzed data from the InSight lander and simulated the properties of rocks in the Martian crust. Seismic measurements helped researchers from the Scripps Institution of Oceanography and the University of California, San Diego and Berkeley, led by Vashan Wright, discover water that is missing on Mars. Based on their calculations, the water is located in fractured igneous rocks between 11.5 and 20 kilometers deep. There is an entire ocean there, with a thickness ranging from one to two kilometers if it were located on the surface.