Hydro-thermal Vents

Source: http://www.whoi.edu/page.do?pid=83497&cl=70453&tid=5122
This video shows the importance of Hydro-thermal vents in the world and explain how they are formed.

Source: http://oceanservice.noaa.gov/facts/extreme.html

This is a picture of extremophile bacteria found near the vents that could plausibly survive on other planets.

Source: http://adcp.whoi.edu/main/topic/hydrothermal-vents

This is a picture of a "black smoker" vent taken during a WHOI research dive