Life is probably, possibly going on not on Mars, but under the frozen crust of Enceladus, one of the many moons surrounding the ringed giant Saturn. Nasa’s Cassini spacecraft has picked up the presence of hydrogen plumes emanating from Enceladus. The only plausible source for the plumes, says the journal Science, is a chemical reaction between warm water and rocks on the floor of the liquid oceans existing miles below the frozen surface of Enceladus. And this indicates the possibility of life. But not life as we know it...
If life exists under the crust of Enceladus, a tiny dot about as big as England, it is clearly not the sort of life which includes smartphones, Breaking Bad and Jane Austen. Or Studio Ghibli films and the Humber Bridge. Or wattle and daub buildings. Or even ammonites. This is life (possibly) which consists (perhaps) of single-celled extremophiles, or microbes, which use hydrogen as a source of chemical energy.
Microbes are pretty basic – they haven’t even yet taken the critical step into becoming multiple celled linked clusters, the sort which lived in the primeval “soup” sloshing around on Earth a few billion years ago. So we have a bit of time to wait until our single-celled friends get going on producing something more complex – if they even manage to do so.
Scientists in labs have demonstrated how the building blocks of life manage to get together to make complex, self-replicating molecules, but as Physicsoftheuniverse.com puts it: “The odds of this complicated process arising extemporaneously must be considered vanishingly small.”
I know that finding even tiny single-celled affairs somewhere other than on our planet is important, because if it happened twice, it’s probably going on elsewhere in the universe, and that is very important. But it’s never going to be proven. If we are all still supposing stuff about our own solar system, evidence for anywhere else has still got to be an informed possibility.
Meanwhile, how far away is Enceladus? No scientist is ever going to get there soon. The idea that we might be able to use it as some sort of holiday home and decamp there when Earth has been swallowed up by the sun is the stuff of sci-fi. It is 790 million miles away. It took Cassini 20 years to get to Enceladus and having made its big discovery, the craft has now run out of fuel and is going for self-imposed destruction. This September it will pass through the icy rings of Saturn and be vaporised in a moment.
Not that anyone or anything on Saturn or its multiple moons will notice and care. The fact that there are plumes of hydrogen coming out of Enceladus, and hence the possibility of microbes, only makes the outer reaches of the solar system seem all the more terrifyingly cold and insensible.
Who can find solace in a microbe? I don’t find the notion that there could be blobs bumping around in an ocean under a frozen crust on a rock 790 million miles away comforting. It only makes life on Earth seem even more precious and unique.
Yes, Cassini has provided evidence that life can be supported elsewhere in space, but compared to the riot of sophisticated, complex and glorious existence currently inhabiting the third rock from the sun, it is bleak. It makes me shudder and want to dive back into protecting this world, our world and its continuation. Beam me nowhere, Scotty.