Blue Mars(199)

They shot over the asteroid belt, slightly out of the plane of the ecliptic, passing over several of the hollowed-out little worlds, no doubt, though it was hard to tell; inside the rock potatoes shown on the ship’s screens there might be rough shells like finished mines, or towns landscaped into beautiful estates; societies anarchic and dangerous, or settled by religious groups or utopian collectives, and painfully peaceable. The existence of such a wide variety of systems, coexisting in a semianarchic state, made Zo doubt that Jackie’s plans for organizing the outer satellites under a Martian umbrella would ever succeed; it seemed to her that the asteroid belt might serve as a model for what the entire solar system’s political organization would become. But Jackie did not agree; the asteroid belt was as it was, she said, because of its particular nature, scattered through a broad band all around the sun. The outer satellites on the other hand were clumped in groups around their gas giants, and were certain to become leagues because of that; and were such large worlds, compared to the asteroids, that eventually it would make a difference with whom they allied themselves in the inner system.

Zo was not convinced. But their deceleration brought them into the Jovian system, where she would have a chance to put Jackie’s theories to the test. The ship ran a cat’s cradle through the Galileans to slow down further, giving them close-ups of the four big moons. All four of them had ambitious terraforming plans, and had started to put them into action. The outer three, Callisto, Ganymede, and Europa, had similar initial conditions to deal with; they were all covered by water ice layers, Callisto and Ganymede to a depth of a thousand kilometers, Europa to a depth of a hundred kilometers. Water was not uncommon in the outer solar system, but it was by no means ubiquitous either, and so these water worlds had something to trade. All three moons had large amounts of rock scattered over their icy surfaces, the remnants of meteoric impact for the most part, carbonaeous chondrite rubble, a very useful building material. The settlers of the three moons had, on their arrival some thirty m-years before, rendered the chondrites and built tent frameworks of carbon nanotube similar to that used in Mars’s space elevator, tenting spaces twenty or fifty kilometers across with multilayered tent materials. Under their tents they had spread crushed rock to create a thin layer of ground— the ultimate permafrost— in some places surrounding lakes they had melted into the ice.

On Callisto the tent town built to this plan was called Lake Geneva; this was where the Martian delegation went to meet with the various leaders and policy groups of the Jovian League. As usual Zo accompanied the delegation as a minor functionary and observer, looking for opportunities to convey Jackie’s messages to people who could discreetly do something about it.

This particular meeting was part of a biannual series the Jovians held to discuss the terraforming of the Galileans, and so a good context for Jackie’s interests to be expressed. Zo sat at the back of the room next to Ann, who had decided to sit in on the meeting. The technical problems of terraforming these moons were big in scale, but simple in concept. Callisto, Ganymede and Europa were being dealt with in the same way, at least at the beginning: mobile fusion reactors were out roaming their surfaces, heating the ice and pumping gases into early hydrogen/oxygen atmospheres. Eventually they hoped to create equatorial belts where gathered rock had been crushed to create ground over the ice; atmospheric temperatures would then be kept near freezing, so that tundra ecologies could be established around a string of equatorial lakes, in a breathable oxygen/hydrogen atmosphere.

Io, the innermost of the Galileans, was more difficult, but intriguing; rail-gun launchers were firing large missiles of ice and chaldates down to it from the other three big moons; being so close to Jupiter it had very little water, its surface made up of intermixed layers of basalt and sulfur— the sulfur spewing out onto the surface in spectacular volcanic plumes, driven by the tidal action from Jupiter and the other Galileans. The plan for Io’s terraformation was more long-term than most, and was to be driven in part by an infusion of sulfur-eating bacteria into hot sulfur springs around the volcanoes.

All four of these projects were slowed by the lack of light, and space mirrors of tremendous size were being built at Jupiter’s Lagrange points, where the complications of the Jovian system’s gravitational fields were reduced; sunlight would be directed from these mirrors to the equators of the four Galileans. All four moons were tidally locked around Jupiter, so their solar days depended on the length of their orbits around Jupiter, ranging from forty-two hours for Io to fifteen days for Callisto; and whatever the length of their days, they all received during them only four percent as much sunlight as the Earth. But the truth was that the amount of sunlight hitting the Earth was stupendously excessive, so that four percent was actually a lot of light, when it came to visibility— seventeen thousand times as much as the full moon on Earth— but not much heat, if one wanted to terraform. They therefore were cadging light any way they could; Lake Geneva and all the settlements on the other moons were located facing Jupiter, to take advantage of the sunlight reflected from that giant globe in the sky; and flying “gas lanterns” had been dropped into the upper atmosphere of Jupiter, clusters of them igniting some of the planet’s helium3 in points of light that were too brilliant to look directly at for more than a second; the fusion burns were suspended before electromagnetic reflecting dishes that put all the light out into the planet’s plane of the ecliptic. Thus the banded monster ball was now made an even more spectacular sight by the achingly bright diamond dots of some twenty gas lanterns wandering its face.