The latest find on Jupiters moon Europa offers the potential to really look for life. Its not time to shy away and Nasa needs to rise to the challenge
For a decade now, the Nasa mantra for looking for life in outer space is to follow the water. In the beginning, this was a valid way to identify the places where we should then start searching. Each new discovery of water is automatically paired with a statement that this increases the chance of finding alien life. But in recent years the latest example being the discovery of water this week on Jupiters moon Europa we have been hearing it so often that it is starting to become boring.
When I say life, I dont mean little green men who say: Take me to your leader. Microbes will do because the discovery of single alien microbe would be the greatest advance that science could ever make. We still do not know how life began on Earth. If we could find some elsewhere, we could look to see how similar or different it was from Earth life. Does it rely on DNA, for example? Do its similarities and differences hold clues about how it, and therefore we, were formed?
However, this is where the risk and the fear of failure lies. Despite what you might think from the news stories, water is no guarantee of life. Water is certainly a prerequisite on Earth and there are good scientific reasons for believing water may be essential for life of any description, but there is no guarantee that a watery celestial body will automatically play host to microbes.
Perhaps this is the reason that Nasa has seemed strangely reluctant to take the next step of actually looking for life. Earlier this century, they shied away from the Terrestrial Planet Finder, a telescope designed to look for Earth-like worlds and analyse their atmospheres for traces of life. With their Mars Curiosity rover in 2012, they specifically did not put any life-detecting equipment on board.
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