Life at the Extremes

Courtesy of the NOAA

 

Hydrothermal vents are home to many species of bacteria, invertebrates and others. These environments exist completely independently of the Sun, and instead rely upon colonies of bacteria that perform chemical reactions on volcanic products.

Models for extraterrestrial life?

So far, the extreme conditions considered here have been those found on our own planet. But environments found elsewhere in the Solar System are much more inhospitable. Could life as we know it survive beyond Earth and what form might this life take? Study of extreme environments has led many experts to believe that extraterrestrial life may resemble the pioneering single-celled extremophiles.

The planet Mars is the most similar to Earth and a favourite candidate for extraterrestrial life. Slightly further from the sun than Earth, it is colder with a surface temperature range of -10 degrees C to -76 degrees C. Beneath the surface, temperatures are likely to be much warmer and liquid water may exist.

Europa is one of Jupiter's largest moons. Surface temperature is an icy -145 degrees C, but 1-10 km underground there appears to be a very deep ocean of liquid water. Scientists believe that the ocean is warmed by volcanic and tidal activity caused by the gravitational pulls of nearby Jupiter and other moons. Some even speculate that there are hydrothermal vents at the bottom of Europa's ocean. If this is the case, life on the moon seems much more likely.

Astronomically speaking, there are only two candidates for extraterrestrial life within our own neighbourhood. But the discovery of planets beyond our own Solar System has re-ignited interest in extraterrestrial life. Such discoveries are accelerating due to advances in detection, and to date over 200 have been documented. At this point in time, we can only speculate about conditions on these worlds, and the life that may inhabit them.

ScienceDaily - Life Cycle Mapped Of Unique Organism In Extreme Environments
http://www.sciencedaily.com/releases/2007/02/070228092550.htm

Astrobiology Web - Life in Extreme Environments
http://www.astrobiology.com/extreme.html