The Universe Below

"When I read this book I was only two years into this new field I was working in. I was impressed by three things. One is that what stimulated this book was the discovery of deep-sea vent communities. This was back in the late 70s. Scientists sent a submersible and discovered that around these deep-sea vents you had riftia tubeworms and crabs and shrimp, and they were all feeding off of bacteria, not requiring photosynthesis. That was a big shock for the biological community. Life was never the same after that. “Anybody with a really good telescope can go search for their own exoplanets, particularly if they’re around red dwarfs.” Another is that he goes back in time, to the voyage of the Beagle and other epic 19th-century expeditions where people were trying to figure out what was deep beneath the ocean. The idea then was that, hidden in the really deep waters, were prehistoric beasts. There was the fishing crew that recovered a Cretaceous coelacanth and made them think there was a domain of animals down there from the Mesozoic. The third interesting aspect is that once the Department of Defense developed submersibles designed to rescue submarine crews from disabled submarines at depth, they were turned into scientific tools. A general in the navy department manipulated the funding so that marine scientists could get access to these tools and explore the deep. It reminded me of the situation I was involved in with the Department of Energy, which was the primary supporter of research into subsurface life. It was the programme that started the investigations anew. Frank Wobber, as programme manager, kept this programme alive for ten years until finally the DoE pulled the plug. It seemed very parallel to our own experience: first exploring a complete unknown, secondly the idea deep life was ancient, thirdly the politics behind big science. Without the Department of Energy, God knows how many decades would have passed before people started thinking subsurface life is something worth pursuing. Because you’re at a higher pressure and low temperature, there are some similarities. But deep-marine ecosystems are complex mixtures of different kingdoms and bacteria, and there’s always oxygen down there and that’s why these organisms exist—because they’re breathing dissolved oxygen. When you go into the subsurface, you’ve got the pressure, you’ve got higher temperatures, and you don’t have the oxygen. So now you’re exploring a different domain of life, where predominantly bacteria live, or any type of multi-cellular animal that can live off tiny amounts of oxygen or by some other means. Those are the main differences between these two domains of life. The initial perceptions as we were going into this field were that the life forms would always be very primitive and their level of activity would always be very slow and that, in order for them to do anything, you’d have to stimulate them to do something. Over the course of my book, you discover that, in fact, these systems are far more complex than we could have imagined and that they’re extremely active and they’re constantly churning over energy and nutrients and carbon. They’re very efficient at recycling all their waste products as well. That’s different from what you see in the deep marine systems, where you have the mass expanse of open space and water and dissolved oxygen and you’re living off whatever’s coming down from above that’s being fed by the photosphere. The subsurface is completely detached from the photosphere of our planet, so the ice ages can come and go, meteorite impacts can evaporate the oceans, but that won’t affect these guys down there, a mile or two underground."