Gwynne Dyer: Life, but maybe not as we know it

Gwynne Dyer

ONLY 39 light-years away, astronomers have found seven planets circling a very small "red dwarf" star called Trappist-1. All seven are in or near what we call the "Goldilocks zone": not too hot, not too cold, but just right for water to remain liquid on the planet. So we all speculate once again, but a little more bravely this time, about whether some of these planets might be home to life.

Not only are three of Trappist-1's planets dead centre in the Goldilocks zone; the other four are on the fringes of the habitable zone. And they are all big enough -- from half Earth's size to slightly bigger than our home planet -- to retain an atmosphere for billions of years.

If an intelligent life form evolved on even one of these planets, it could have colonised all seven: they are very close together. The journey would be not much more demanding than a trip from the Earth to the Moon.

So think about that: a seven-world interplanetary civilisation. It may not exist at Trappist-1: we cannot yet assume that life crops up everywhere that the circumstances are suitable for it. But it surely must exist in one or many (or most) of the hundreds of millions of similar star systems that exist in this galaxy alone.

It looks like life is as common as dirt in the universe, which for living creatures like us is infinitely more interesting than a dead universe ruled only by physics and chemistry. Whereas the poor scientists, shackled by their duty to go not one millimetre further than the evidence will currently support, are condemned to say cool, restrained things like: "The discovery of multiple rocky planets with surface temperatures that allow for liquid water make this amazing system an exciting future target in the search for life." (Dr Chris Copperwheat of Liverpool John Moores University, which provided one of the telescopes used in the study.)

But I am a journalist, and I am allowed to speak obvious truths even when the scientific evidence is still falling a bit short. Planets are self-evidently as common as dirt. Life is almost certainly as common as dirt. And even intelligent life must be pretty common in the universe.

Maybe only one planet in a million has intelligent life, you say? Okay, then there are at least 140 million planets with intelligent life in this galaxy alone. And there are at least 100 billion galaxies.

I started reading science fiction when I was quite young -- maybe 10 or 11 -- and my parents knew an old guy a few streets away who was an amateur astonomer, so they sent me along to see him. He showed me his telescope, and pictures he had taken, and even an exercise book where he had done sketches of our own solar system and the entire galaxy with coloured pencils.

But he couldn't tell me whether there were any planets beyond our own system, let alone whether there was life elsewhere in the universe. Nobody knew, and he was being properly scientific in his caution. So I returned to my science fiction, and never went back to see him again.

I am probably now at least as old as that "old guy" was then. We live in a truly marvellous time, when the whole universe is opening up to us, and I wish he could have lived long enough to know what we know now.

And now for the next perplexing question. If life is as common as dirt, and intelligent life only maybe 1000 times less common, then where is everybody? . Meanwhile, a private consortium led by the BoldlyGo Institute and Mission Centaur is working on an orbital telescope that will look for planets around our closest stellar neighbour, Alpha Centauri, only 4.4 light-years (40 trillion kilometres) away.

Gwynne Dyer is an independent journalist whose articles are published in 45 countries.