The Ross Ice Shelf in Antarctica is a most inhospitable land. The ice is so thick that until this year, scientists thought that no life could exist beyond that of microbes. But a team of scientists proved everyone wrong when they sank a probe into the sea bottom below the ice and discovered the area full of life with a variety of different organisms including fish.
If life can exist in these types of conditions here on Earth, the possibility that it also exists elsewhere in our solar system increases dramatically. For instance, what could lie beneath the ice of Jupiter's moon Europa or perhaps Saturn's moon Enceladus?
"Discoveries of extreme life here on Earth often provoke speculation about what might lurk in other words," wrote Scientific American's Douglas Fox. "... People asked what this might mean for finding life on distant worlds such as Europa, a moon of Jupiter that very likely harbors an ocean of liquid water beneath a crust of ice."
In a paper published in Nature, the case has now been made that Saturn's moon Enceladus could have what it takes to support life. In 2005, NASA's Cassini spacecraft found evidence of geysers that may have emitted plumes of water. Now, NASA has found what it calls "the first clear evidence" that those plumes could be linked to an active hydrothermal system in the moon "which may resemble that seen in the deep oceans on Earth."
My colleagues and I are optimistic that evidence for life, either elsewhere in our solar system or elsewhere in the universe, may be discovered in the coming decades," Lawrence M. Krauss wrote in the New Yorker in late January.
"There are a host of possible sites where life might have evolved that were long considered unlikely," Krauss wrote. "... On Earth, scientists have had to revise old rules about where and how life can survive. The discovery of so-called extremophiles ... has vastly increased the set of conditions under which we can imagine life existing on this planet."
The search for extraterrestrial life has transformed itself from the realm of science fiction to scientific pursuit. While it may seem like an almost hopeless pursuit as so many factors ensured the development of life here on Earth, these new discoveries have opened the possibility that we may not be alone in our own solar system.
"By considering each of these many factors and imagining the probability of each separately, one can imagine that the combination is statistically very unlikely, or impossible," Krauss wrote of Earth's chances. But that's not so, he said. Rather, recent research and the discovery of these extremophiles indicate how life can sprout in ways scientists never imagined.
If organisms such as a fish can exist here on Earth below a half-mile of ice in an area that is hundreds of lateral miles removed from sunlight, there is no reason that it shouldn't be able to exist under the ice on moons such as Enceladus.
