This drawing shows a cross-section of the Martian frozen ground.
Click on image for full size
The drawing shows the depth at which water may be frozen into the ground. To have water running on the surface of Mars, this water region must be near to the surface. This may have happened at various times in the history of Mars as the climate warmed.
Shop Windows to the Universe Science Store!
Learn about Earth and space science, and have fun while doing it! The games
section of our online store
includes a climate change card game
and the Traveling Nitrogen game