Alcoves as Havens From a Harsh Martian Environment.

Future missions to Mars will undoubtedly be directed toward sedimentary terrains in search for evidence of past life and geologic history. Astronauts will need to find shelter from harsh surface conditions. Natural underground voids provide a readily adaptable habitat for crews to shelter from radiation. Naturally formed caves would be desirable habitat sites, but thick deposits of limestone or other soluble rocks in which karst topography would form have not been identified by current observations. Alcoves, arched recess in steep escarpments, should be widely distributed across the planet and provide an adaptable shelter for astronauts operating on the surface of Mars. Alcoves provide a more stable thermal environment, a reduced radiation environment, shielding from macro‐ and micro‐meteorite impacts, and protection from atmospheric disturbances. Plain Language Summary: Future Mars explorers will face a hostile environment that includes high radiation, extreme temperatures, and high windstorms. Establishing safe living quarters for prolonged stays presents problems like those of early man on Earth. The choices are whether to bring a suitable structure; to build a structure; or to find and adapt underground facilities. Of these choices, finding natural shelters requires less transported materials and less expenditure of energy than surface shelters. Lava tunnels may be useful, but future explorers will require safe quarters in the areas of Mars where sedimentary rocks are common, which will be important exploration targets to determine the geologic history of Mars. Caves in sediments on Mars may be difficult to find, but alcoves may be present. Unlike caves, alcoves have large openings at the surface in rock escarpments. Early humans used alcoves as natural shelters. Even as construction techniques developed, structures were placed within alcoves for additional protection. The Mesa Verde alcoves and pueblos in Colorado are examples of the adaptation of terrestrial alcoves for protected sites. Similarly, future astronauts to Mars could adapt shelters within alcoves as bases for operation. The earliest shelter could be as simple as a sealed tent containing a suitable atmosphere and pressure erected in an alcove. Key Points: Sedimentary rocks on Mars will be a high‐priority target for astronauts as they will reveal much of the geologic historyAlcoves provide potential habitats for future explorers on MarsAlcoves provide protected environments and possible water sources for primitive lifeforms on Mars [ABSTRACT FROM AUTHOR]