The Life Scientific: Robert Ballard

Well, that project

really proved Alvin's value and paved the way for that groundbreaking discovery I mentioned earlier.

In 1977, while diving on the Galapagos Rift, your team discovered a phenomenon that would reframe our understanding of ocean biology, hydrothermal vents.

Talk me through how that came about.

Well, like a lot of discoveries, we bumped into them.

When I was doing my thesis, I had half my committee believed in plate tectonics and the other half did not.

They said, well, I can understand when two plates come together and crash into one another like you have off of India crashing into China.

But how do you make a mountain when you pull plates apart? And my co-scientist on the expedition was a geophysicist.

He said, it's a cooling curve.

When the lava first comes out and forms the new lithosphere, the new crust, it's swollen with heat energy.

It's a blister.

But as it moves away from its site of genesis, it gets denser.

So he went out in the Atlantic and said, I'm going to drop a heat probe into the bottom, and I'm going to tell you in advance what the temperature is.

And sure enough, all along that mountain range, the temperature was exactly what he predicted, except at the very axis.

And he said, how can you be 99% right? There must be hot springs.

So when we went out to the Galapagos Rift, we wanted to find what we call the Delta T, the missing heat.

So we went looking for hot springs.

We went down and looked out our window and there were these giant tube worms and clams and complete ecosystem.

It was like an oasis in the Sahara Desert.

And we realized when we got the first clam, it was a giant clam, And their whole body was full of chemosynthetic, what we call extremophiles, that can ingest this fluid, which has poisonous hydrogen sulfide in solution, will oxidize it in total darkness and create a replica of photosynthesis in the dark.

And this really opened the ballgame.

Because before that discovery, we thought we lived in the Goldilocks of the solar system, not too close to the sun, not too far away.

All of a sudden, we realized that you could have life elsewhere, even within our

own solar system.

I mean, that's fascinating because, as you say, these creatures that were living down by these hydrothermal vents, too deep in the ocean for any sunlight to carry out photosynthesis, but they're carrying out this chemosynthesis.