This map shows the abundance of water ice around the northern polar regions on Mars. Purple and blue indicate lots of water, while yellow and red indicate drier regions. The ice-rich region at the North Pole is the North Polar Ice Cap on Mars. Other areas have smaller amounts of ice buried a few inches beneath the soil. The Mars Odyssey Orbiter spacecraft detected gamma rays from hydrogen atoms in the water molecules in 2002 to make this map.
Image courtesy of NASA/JPL/UA.