Planetary Caves' Role in Astronaut Bases and the Search for Life

Detailed Description
During the 2nd International Planetary Caves Conference, attendees explored Lava River cave, located near Flagstaff, Arizona. This photo was taken using time-lapse photography and the light streak is the result of person walking with a headlamp. Sitting down is USGS scientist Timothy Titus.
Sources/Usage
Public Domain.