Far out, man

There’s a song by a band named Dreadzone that starts like this: “It’s a mathematical certainty that somewhere among the millions of stars, there is another planet that speaks English.”

Mathematical certainty that there is intelligent life elsewhere in the universe is all very well. As the researchers gazing upon exoplanet K2-18b through the James Webb Space Telescope have discovered, the first question is to define “life”. The researchers have identified tentative traces of dimethyl sulphide and dimethyl disulphide — gases that on Earth are produced only by marine micro-organisms such as phytoplankton.

K2-18b is roughly three times the size of Earth and nine times heavier, and sits in the “Goldilocks zone” of its sun, where temperatures could support water in liquid form, and possibly life itself.

Whatever it may mean — or not — to us frail humans, it is a phenomenal scientific discovery.

In one sense, it’s vindication for those who believe in the Drake equation, named for astrophysicist Frank Drake, who developed a probabilistic theory to estimate the number of civilisations in the Milky Way. The theoretical estimates ranged between 1,000 and 100-million life-supporting planets.

Criticism, naturally, has been robust, for obvious reasons — it’s hard to do a fly-by to check it out. K2-18b is 120 light years or about 1.14-quadrillion kilometres from Earth, too far to send the current US administration for an inspection in loco, though that would raise interesting crowdfunding possibilities.

Our hubris being what it is, we believe that any intelligent life out there must look and be more or less similar to us, when the truth is it’s likely to be plankton.

The last word on civilisation existing somewhere in our universe, then, is left to Calvin and Hobbes, his stuffed (but real to him) philosophical tiger. “The surest sign that there is intelligent life out there,” says Calvin, “is that none of it has tried to contact us.”