Life hangs in the balance

SOMEWHERE or other, out there in the universe, do you suppose there’s an alien version of Professor Brian Cox, currently appearing on the alien equivalent of BBC Two? Wouldn’t it be exciting if there were? Or at least I think it would.

And if there is indeed an alien Prof. Cox, do you suppose his latest TV series is about to ponder the biggest question of all – namely, whether or not there’s another planet like his, capable of sustaining life?

That’s what our own Prof. Cox is doing tonight.

In episode two of UNIVERSE (BBC2, 9pm), Brian (I’m going to call him Brian from now on, otherwise it becomes a bit of a mouthful) explains how far our search for a “second Earth” has broadened in recent years.

“In my adult lifetime,” he tells us, “we’ve gone from a universe that could have been devoid of planets beyond our own solar system to a universe that we know is teeming with places that we can search for life.”

Effectively what he’s saying is that if David Bowie were alive today and wanted to re-write Life On Mars, he’d probably ask instead if there’s life on 51 Pegasi b (an extrasolar planet discovered in 1995) or on Kepler-36b (first spotted in 2012). From a lyrical perspective, obviously both these rewrites would have sounded dreadful – on a par, I’d imagine, with much of his 1987 album Never Let Me Down – but the question they’d have posed would have been a valid one.

Well, up to a point. Kepler-36b, which is 1,533 light years away, is a world which “at first glance might seem quite familiar”, a new class of planet dubbed a “super Earth”.

But on closer inspection, it’s not that super.

A big snag is that one of its hemispheres permanently faces the “parent star” (the planet’s equivalent of our own sun), while the other permanently faces away from it. So one half of this plant is stupidly hot (molten ground, rivers of lava, that kind of thing), while the other is freezing cold and constantly dark.

Overall, think of Iceland but a bit more extreme.

Also, Brian points out, this planet has “a gigantic, gaseous companion”.

(I can already predict my wife’s witty reaction when she hears that line).

So that’s no good either. Brian’s hunch is that, while we now believe there may be “around 20 billion potentially Earth-like worlds”, the odds on all the vital life-supporting factors falling into place are still slim.

Even slimmer are the chances of them staying in place long enough for any life form to become fully civilised like ours.

Meanwhile, on THE REPAIR SHOP (BBC1, 8.30pm), they’re mending a butter churn.