With all those burners and flues, Tycho is heavily industrial — something like Pittsburgh used to be, or the Ruhr cities. And with the same darker social side. They burn the biomass to recover volatiles, before burying the carbon-rich residue. It’s all part of the global scheme to maximize the production of free oxygen, which not many of us understand… But Tycho is one of the few places where the work we’re doing is simple enough for a five-year-old kid to contribute to.

I’ve taken Nadezhda around the place I work, the oxygen fountain at Landsberg. It sounds exotic — the ten-thousand-megaton thermonukes, the controlled energy cascades from Moonseed beds, all of it cracking the lunar regolith for oxygen — but there isn’t much, really, to see.

It can be a little bleak here.

For the foreseeable future, humans are going to be consuming eighty per cent of the lunar biosphere’s net primary production. And that’s a hell of a lot, maybe three times as high as humans ever reached on old Earth.

That means all the arable land surface we make, even most of the plankton in the crater lakes, is going to have to be turned over to crops. Other than humans, only those creatures that can survive in fields and orchards can be permitted. Any that need virgin forest or any kind of undisturbed habitat are going to have to stay in the zygote banks for now.

They tell me it’s going to take all of ten thousand years before we’re stable and self-regulating, before a human will be able to take off her resp mask and walk out of the domes… Still, we’re promised the first trees and grasses under the Copernicus dome before the decade is out. They are concentrating for now on developing the most useful crops: food, like potatoes, bananas, yams, sugar-cane, coconut; but also gourds and bamboo and plants we can use to make tapa cloth, dyes and oil.

It’s a grand vision, for all that. When the full terraforming gets started, the ecologists say it is going to be like the colonization of new volcanic islands, like Hawaii. The few species we release here to this native soil will explode into all the niches they find, over time, and diversify, new plants and animals to complete the colonization of the Moon. No doubt producing a new ecosystem the like of which Earth never saw.

But that will take a million years, they say. I wish I could fast-forward to see it. Morning on the Moon…

Henry checked his recording equipment, balky modern stuff which he didn’t know how to work, and thought about Earth.

It was the great tectonic events, of course, which had done the greatest damage. There had been the great lava flows off the east African coast, six thousand square miles of new basalt spilling in waves across the land, spewing out gases; everyone thought that was a stupendous catastrophe.