Nick Lane

Hydrogen, oxygen, these are all elements that are very, very common in the universe.

So you're going to keep on getting this same kind of chemistry everywhere.

We know that there are, from discoveries of exoplanets in recent years, if you extrapolate how many we've not seen yet, the number of wet rocky planets or moons in, say, the Milky Way, is probably in the order of 20, 30, 40 billion of them.

I mean, I'll take a punt here.

I would expect that if you've got these same kind of conditions on a wet, rocky planet, you're going to be producing these same kind of vents because it's the same chemistry that's going to happen.

You're going to be dealing with hydrogen.

No, the vents are produced by a mineral called olivine, which again is really common in interstellar dust.

And the mantle of the Earth is made of this mineral called olivine.

And it will react with water.

And when it reacts with water, it's slow.

If you were to put a lump of olivine in a bucket of water, you'll not see very much.

But if you're dealing with the pressures down at the bottom of the ocean and warmer temperatures and so on, you're producing bucket loads of hydrogen gas in alkaline fluids.

So that's what these hydrothermal vents are.

So any wet rocky planet will produce these vents.

There's evidence for them on Mars from the early days of Mars when there were oceans on Mars.

There's evidence now on moons, the icy moons Enceladus and Europa.

You know, this is going on in our own solar system right now.

I mean, my view would be yes.

Any rocky planet would have a decent, yes.

And if you're starting with CO2 and hydrogen, what I'm saying is the metabolism is thermodynamically favored chemistry.