Hotter yet is the environment near hydrothermal vents found near fractures in the ocean floor (these fractures occur where new ocean crust is being laid down by the upwelling of hot magma from below). Here, where temperatures up to 195 degrees Fahrenheit exist, a number of unusual creatures have been discovered and among them is a single-celled organism that produces methane and “fixes nitrogen.” This is the biologic process by which nitrogen from the air becomes incorporated into the nutrients necessary for most surface dwelling creatures. Prior to this finding, nitrogen-fixing had not been found to exist in organisms living at temperatures above 145 degrees F.
It is the existence of these many unexpected and remarkable forms of life that give hope to astrobiologists searching for life on other planets where the typical environment may be more extreme than most of Earth’s habitats.
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