“It still seems to be going very fast to me. And all of this must have happened before the soletta.”

“The thing is,” Jessica said from her desk across the room, “there isn’t any competition at this point. Conditions are harsh, but these are very hardy plants, and when we put them out there, there isn’t any competition to slow them down.”

“It’s an empty niche,” Claire said.

“And conditions here are better than most places on Mars,” Berkina added. “In the south you’ve got the aphelion winter, and the high altitude. The stations down there report that the winterkill is just devastating. But here the perihelion winter is a lot milder, and we’re only a kilometer high. It’s pretty benign, really. Better than Antarctica in many ways.”

“Especially in the CO2 level,” Berkina said. “I wonder if that doesn’t account for some of that speed you’re talking about. It’s like the plants are being supercharged.”

“Ah,” Sax said, nodding.

So the fellfields were gardens. Aided growth rather than natural growth. He had known that, of course— it was a given everywhere on Mars— but the fellfields, so rocky and diffuse, had looked spontaneous and wild enough to momentarily confuse him. And even remembering they were gardens, he was still surprised that they were so vigorous.

“Well, and now with this soletta pouring sunlight onto the surface!” Jessica exclaimed. She shook her head, as if disapproving. “Natural insolation averaged forty-five percent of Earth’s, and with the soletta it’s supposed to be up to fifty-four.”

“Tell me more about the soletta,” Sax said carefully.

They told him in a kind of round. A group of transnationals, led by Subarashii, had built a circular slatted array of solar sail mirrors, placed between the sun and Mars and aligned to focus inward sunlight that would have just missed the planet. An annular support mirror, rotating in a polar orbit, reflected light back to the soletta to counterbalance the pressure of the sunlight, and that light was bounced back onto Mars as well. Both these mirror systems were truly huge compared to the early freighter sails Sax had enlisted to reflect light onto the surface, and the reflected light they were adding to the system was really significant. “It must have cost a fortune to build them,” Sax murmured.

“Oh, it did. The big transnats are investing like you can’t believe.”

“And they’re not done yet,” Berkina said. “They’re planning to fly an aerial lens just a few hundred kilometers above the surface, and this lens will focus some of the incoming light from the soletta, until it heats the surface up to fantastic temperatures, like five thousand degrees—”

“Five thousand!”

“Yes, I think that’s what I heard. They plan to melt the sand and the regolith underneath, which will release all the volatiles into the atmosphere.”

“But what about the surface?”