Liquid Water on Present-Day Mars

摘要

Near-surface environmental conditions on Mars today are generally considered inadequate to permit liquid water to exist in equilibrium with the atmosphere. Mean annual temperatures are about 50-60 kelvin (K) below the melting point. and mean annual surface pressures are very close to the triple point. Yet there are localized regions where, for a few hours of the day at the right time of year. surface temperatures and pressures meet the minimum requirements for the existence of liquid water: pressures and temperatures above the triple point of water but below the boiling point.