It has been theorised that Jupiter's fourth largest moon Europa may be able to sustain life within a subsurface ocean that appears to exist under its icy crust. It was previously believed that life could not be sustained without sunlight. However in 1977, lifeforms were discovered in the depths of the Galapagos Rift that proved life doesn't necessarily need sunlight to survive.
The fact is that Europa appears to have heat and liquid water: Two conditions we know are essential for sustaining life. If extraterrestrial life does indeed exist within Europa's under ice ocean, it would be surviving in an environment not unlike the waters under Antarctica and is likely to comprise of micro-organisms.
Europa is now considered to be the Solar System's most likely candidate for extraterrestrial life. The other likely candidates are Mars and Saturn's moon Titan. The idea of life on Europa seemed even more likely when evidence of life on Mars appeared in 1996.
The discovery made in the Galapgos Rift showed that life need not depend on photosyntheses, as previously thought, but can survive due to chemosynthesis. This provides a model for life on Europa as energy generated by tidal flexing and the fact that the water is kept from freezing by Europa's volcanic activity could allow for this chemosynthesis.
It is also theorised that the volcanic activity could provide such energy. Though this would not allow for anything on the scale of a photosynthesis-based ecosystem, life on Europa could exist as micro-organisms gathered around hydrothermal vents. However, this model for life cannot exist if the ocean is too cold or too salty. But it is possible. Life on earth originated in water, after all.
NASA are now launching the Europa-Jupiter System Mission (EJSM) to discover more about what might lie beneath Europa's icy surface.
Europa is now considered to be the Solar System's most likely candidate for extraterrestrial life. The other likely candidates are Mars and Saturn's moon Titan. The idea of life on Europa seemed even more likely when evidence of life on Mars appeared in 1996.
The discovery made in the Galapgos Rift showed that life need not depend on photosyntheses, as previously thought, but can survive due to chemosynthesis. This provides a model for life on Europa as energy generated by tidal flexing and the fact that the water is kept from freezing by Europa's volcanic activity could allow for this chemosynthesis.
It is also theorised that the volcanic activity could provide such energy. Though this would not allow for anything on the scale of a photosynthesis-based ecosystem, life on Europa could exist as micro-organisms gathered around hydrothermal vents. However, this model for life cannot exist if the ocean is too cold or too salty. But it is possible. Life on earth originated in water, after all.
NASA are now launching the Europa-Jupiter System Mission (EJSM) to discover more about what might lie beneath Europa's icy surface.
