Hydrothermal Origins of Life Theory
Until 1977 scientists believed that all forms of life ultimately depended on the Sun for energy. With the 1977 discovery of the first hydrothermal vent, (Geysers that billow out from the sea floor.) and the teeming, diverse arrays of life surrounding its base Astrobiologists are now believe that life on Earth might have originated in the sulphurous base of hydrothermal vents.
Vent ecosystems are the only system on Earth that we know of where life can thrive in the complete absence of sunlight offering an alternative way for life to meet its fundamental need for energy. They depend on microbes that tap into the geyser water’s chemical energy – energy originating from within the Earth itself.
Amino acids, the building blocks of life from which many of the primitive molecules required to jump-start life form from, could have occurred within these hydrothermal vents. Vent environments minimize oxygen and radiation, which can damage primitive molecules. Along with geothermally-heated mineral-rich water these molecules could have been thrown up into cooler waters where life may have originated
Astrobiologists have struggled for years to define the range of conditions in which “life as we know it” could exist. The discovery of hydrothermal vent ecosystems expanded that range. They were the first discovery of life as we don’t know it and suggest this is a realistic and possible scenario.
The ability of life to tap such geothermal energy raises interesting possibilities for other worlds like Jupiter’s moon Europa, and ancient Red planet Mars.
Europa is squeezed and stretched by gravitational forces from Jupiter and neighbouring Galilean satellites. Its icy surface has, gradually, broken up and reformed into icebergs, but the core is considered molten. Tidal friction heats Europa’s interior possibly enough to maintain beneath the icy surface, the solar system’s biggest ocean where active hydrothermal vents are believed to exist. Astrobiologists theorize that much like the hydrothermal vents at the bottom of Earth’s oceans the ones in Europa’s dark seas be similar enough to provide all of the ingredients needed to support life.
NASA is planning to send a probe to Europa within the next 20 years, which will penetrate the ice layer in search of water and vent debris. Work carried out on Earth suggests that if basic ingredients for the origins of life are there, there is a chance of discovering vent-based life forms,