I’ve been listening to the soundtrack for our upcoming planetarium show, “Earth: An oasis in Space”, and it’s gotten me thinking. The show is all about life in the universe, and how liquid water is a key ingredient for life as we know it. This is what makes Earth an oasis- we have buckets of the stuff. But if we find liquid water elsewhere in the solar system, what does that tell us about life elsewhere? “Necessary but not sufficient” is the way my science profs would have put it – but finding places with liquid water would certainly narrow the search for life. (This show opens at the end of June, by the way… you should come see it!)
So here’s the question: why are we so interested in finding life beyond Earth? From NASA scientists to the UFO “true believers” and everyone in between, the idea of finding life elsewhere seems to be almost universally popular. Is it a desire to not be alone in the vastness of space? Is it a hope that aliens will come and save us from all the problems we face on earth, essentially a big cry for Mommy? Is it pure curiosity, that driving force of humanity that has forged our civilization for millennia?
Of course, we’re not all looking for the same sorts of life. Most scientists in the field expect that the most common sort of life we might find out there will be non-technological: slime molds, bacteria, and other primitive forms of life. And ocean life tends to be non-technological, too: you don’t see dolphins or whales building space probes or sending radio signals into space like humans do, despite their obvious intelligence. Even if the universe is teeming with life, most of it will be totally invisible to us until that first astronaut steps off the ladder and pokes it with their finger – and that’s a *really* long way off technology-wise.
There are several places within our own solar system that may have once harbored primitive life: Mars, for example. There are even a couple, like Jupiter’s moon Europa, that may have life currently there right now, just waiting for us to find it. Until then, the search continues… sort of. Listening for aliens via radio will only detect the most advanced civilizations out there, while ignoring the much larger number of worlds with potential primitive life. Space telescopes can find planets with oxygen atmospheres and water vapour as likely candidates, but until we start sending robots or people out into space again, we’re not going to *know*.
This is why some of the long-ranged plans are pretty exciting. NASA and the European Space Agency are thinking about a big mission to the Jupiter system using two spacecraft sometime in the 2020’s. The Europa Jupiter System Mission would determine if any of Jupiter’s moons are habitable worlds – but it’s not funded yet and it’s a long way off. The Mars Science Laboratorywill give Mars another once-over, and be able to do more on-site science than previous missions, including trying to figure out where all the carbon comes from – on Earth, it comes from the actions of life. There are lots of other ideas on the drawing boards for the late 2010’s and 2020’s. Until then, inquiring minds still want to know but are left to wonder.
This is why some of NASA’s upcoming missions are exciting.