Learn with the astronauts on ESA's underground training course CAVES as instructor Jo de Waele introduces astronauts to the karst geology that form caverns and caves.

This is part three of the five-part lecture that was given during ESA's CAVES 2013 training course offering an overview of the environment the astronauts would explore. ESA astronaut Paolo Nespoli, Canadian astronaut Jeremy Hansen, Russian cosmonaut Aleksei Ovchinin, Japanese astronaut Satoshi Furukawa and NASA astronauts Mike Barratt and Jack Fischer were present at the lecture.

CAVES stands for Cooperative Adventure for Valuing and Exercising human behaviour and performance Skills. The two-week course prepares astronauts to work safely and effectively in multicultural teams in an environment where safety is critical -- in caves.

Held each year, CAVES teaches astronauts to explore the underground system of the Sa Grutta caves in Sardinia, Italy, as a team, delving deep underground to perform scientific experiments as well as chart and document their activities.

Video 3: How do caves form by the action of water? What does the shape of a cave tell us about its formation? What are the main prerequisites for a cave to form? What are the three phases of speleogenesis (cave formation)? How long does it take to form a cave? Is a cave formed by dissolution or erosion?

ESA­­­­--V. Crobu & S. Sechi