ice is about eight times as enriched with deuterium as water in Earth's oceans. This means that Mars has lost a volume of water 6.5 times as large as that stored in today's polar caps. The water for a time may have formed an ocean in the low-lying Vastitas Borealis and adjacent lowlands (Acidalia, Arcadia and Utopia planitiae). Had the water ever all been liquid and on the surface, it would have covered 20% of the planet and in places would have been almost a mile deep. This international team used ESO’s Very Large Telescope, along with instruments at the W. M. Keck Observatory and the NASA Infrared Telescope Facility, to map out different isotopic forms of water in Mars’s atmosphere over a six-year period. Gallery See also References External links http://seg.org/podcast/Post/4604/Episode-10-Remote-sensing-on-Mars Podcast describing the use of SHARAD radar data to explore the ice caps https://sharad.psi.edu/3D/movies/SHARAD_PB3D_depth_20161223.mp4 High-resolution movie showing the interior of the north polar ice cap in 3D, as determined with SHARAD radar data https://sharad.psi.edu/3D/movies/SHARAD_PA3D_depth_20170105.mp4 High-resolution movie showing the interior of the south polar ice cap in 3D, as determined with SHARAD radar data Extraterrestrial bodies of ice Ice caps Polar regions of Mars Water on Mars