<http://www.jpl.nasa.gov/images/pia07118-north-polar-layers/#webpage>
<http://schema.org/description>
"NASA's Mars Global Surveyor shows an exposure of finely-detailed layers in the martian north polar region. The north polar ice cap, which is made up of frozen water, is underlain by a thick sequence of layers."
<https://www.jpl.nasa.gov/images/pia07118-north-polar-layers/>