A new NASA paper provides the most detailed map to date of near-surface water ice on the Red Planet.

PASADENA, Calif. (NASA PR) — So you want to build a Mars base. Where to start? Like any human settlement, it would be best located near accessible water. Not only will water be crucial for life-support supplies, it will be used for everything from agriculture to producing the rocket propellant astronauts will need to return to Earth.