Nearly half a century ago, two papers postulated the likelihood of lunar lava tube caves
using mathematical models. Today, armed with an array of orbiting and fly‐by satellites and …

A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and
updated the description of Special Regions on Mars as places where terrestrial organisms …

The presence of liquid water is a requirement of habitability on a planet. Possible indicators
of liquid surface water on Mars include intermittent flow-like features observed on sloping …

By the time eukaryotic life or photosynthesis evolved on Earth, the martian surface had
become extremely inhospitable, but the subsurface of Mars could potentially have contained …

The Antarctic Dry Valleys (ADV) are generally classified as a hyper-arid, cold-polar desert.
The region has long been considered an important terrestrial analog for Mars because of its …

The Martian cryosphere is defined as that region of the crust where the temperature remains
continuously below the freezing point of water. Previous estimates of its present thickness …

Nitrous oxide is a potent atmospheric greenhouse gas that contributes to ozone destruction.
Biological processes such as nitrification and denitrification are thought to drive nitrous …

Water on Mars has been explained by invoking controversial and mutually exclusive
solutions based on warming the atmosphere with greenhouse gases (the “warm and wet” …

Abstract Mars Exploration Rover Opportunity discovered sediments with layered structures
thought to be unique to aqueous deposition and with minerals attributed to evaporation of an …

Thermodynamic conditions suggest that clathrates might exist on Mars. Despite
observations which show that the dominant condensed phases on the surface of Mars are …