Science Fiction Writer
ROBERT J. SAWYER
Hugo and Nebula Winner

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Nebula Award-winning science-fiction writer Robert J. Sawyer writes and presents a weekly science column for the Canadian Broadcasting Corporation's CBC Radio One.

The columns, which have the umbrella title Science FACTION: Commentaries from the Cutting Edge of Science, are produced by Barbara Saxberg in Toronto, and syndicated to local CBC Radio stations across Canada.

Host: On Earth, life began in the seas, and so if you're looking for life in outer space, you should start by searching for water. Here's science-fiction writer Robert J. Sawyer with a look at a watery world that's very close to home ... Robert J. Sawyer: Life started here on Earth in a primordial soup — a mixture of water and organic chemicals, fueled by energy in the form of light from our sun.

Any other place with life in our solar system will probably require that same recipe: liquid water with a dash of organic chemicals — plus sunlight.

Unfortunately, of the nine planets in our solar system, only our own wonderful Earth has liquid water. So does that mean there's no other life in the solar system?

Perhaps not — because there's more to our solar system than just the sun and planets.

For one thing, seven of the planets have moons — in some cases, dozens of them. In total, there are eighty moons in our solar system.

Unfortunately, seventy-nine of them — including our own, the one we call the moon — have no liquid water.

But one, a moon of Jupiter named Europa, is entirely covered by a vast ocean of liquid water.

Sound Effect: Surf crashing

Great! All we need to get life, then, is to add some organic chemicals and solar radiation to this watery stock.

There's just one problem: the ocean covering Europa has a frozen crust of ice sealing it in. It's as if we had the pot full of water ready to make soup, but there was a glass lid on top preventing us from adding any ingredients.

Ah, but moons are deeply affected by the planets they orbit: those planets tug on them constantly with their gravity, producing tidal stresses. We don't see any visible signs of such stresses on our own moon, because it's just a solid hunk of rock. But on Europa, the stresses caused by its mother planet — giant Jupiter — are very much in evidence.

Music: "Jupiter" (from Holst's The Planets)

Indeed, Jupiter's tides cause cracks to constantly appear in the icy crust over Europa's ocean. Those cracks open wide, forming fissures down to the liquid water below — and through those fissures, light from our sun gets in.

Sound Effect: Ice cracking

But that's still not enough to make the soup called life: water plus solar energy equals nothing more exciting than hot water. We still need organic chemicals — complex carbon compounds — to produce life.

Mighty Jupiter to the rescue once again! Its gravitational pull is constantly dragging in comets — and comets are essentially dirty snowballs, polluted by organic chemicals.

Many comets — such as Shoemaker-Levy 9, which made headlines a few years ago — crash directly into Jupiter. But often enough Europa gets in the way, and the comets crash into it, instead.

Thank of it as spatial delivery! The missing ingredients for life — carbon compounds — come pouring down out of Europa's sky in the form of comets. And when those organic chemicals make it through the fissures Jupiter's gravity has opened up in Europa's icy crust, then — voilà! — all our ingredients come together in one place: water, organic chemicals, and light from the sun.

So, there might well be life in the oceans of Europa — NASA is working on sending a probe there to find out for sure. And some of those life forms might even now be looking up through one of those cracks in the ice, spotting our blue planet Earth, and wondering if maybe ... just maybe ... life might exist on that watery world, too.

Sound Effect: Lapping waves.

I'm Robert J. Sawyer.

More Good Reading

Other "Science FACTion" commentaries for CBC Radio
"2020 Vision" scenarios for Discovery Channel Canada
Media backgrounder on Rob Sawyer

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