ENTRANCE TO ENTRANCE: A HUNT FOR ASTROBIOLOGICAL ANALOG SITES IN WIND CAVE

In order to understand the pathways by which life could be sustained in the Solar System, extreme environments on Earth are often used as accessible analog systems. With protection from radiation and isolation from harsh conditions, planetary caves could provide habitable environments on other planets and moons.

Within the Solar System, icy moons, such as Europa and Enceladus, have interstitial lakes containing organic molecules where building blocks for life are thought to exist. Titan’s methane cycle may create caves that are karstic in nature, carved in the organic rich dunes of the surface. Finally, data from Mars presents the possibility of life being harbored in lava tubes. Calcite deposits found on Mars are evidence of ancient waters once existing on the surface of the planet. Evidence of past and present water stores a record of the terrains formation and current potential for life.

The complex nature and varied environments of Wind Cave in Wind Cave National Park provides the opportunity to study many analog environments in a single setting. Ancient lakes with low concentrations of organics but rich biodiversity of life represent some of the purest waters on Earth. Zebra calcites store a record of the water that helped create the cave millions of years ago, while currently forming flowstones provide a glimpse into what may be happening on Titan. Chirt dwelling biofilms provide a test bed for looking for microbes in the regolith of Mars.

By studying analog areas in the cave which resemble our solar system, the minimum conditions by which life can be established in extreme environments can be examined. The isolated biomes and environments of Wind Cave provide a unique opportunity to study organisms in a low-nutrient environment that is both mostly isolated from the external realms, yet remains within human reach. Comparing Wind Cave analogs to features throughout the Solar System expands our understanding of where life might exist outside of Earth.