Blue Mars(33)
• • •
Sabishii was located on the western side of a five-kilometer-high prominence called the Tyrrhena massif; south of Jarry-Desloges Crater, in the ancient highlands between Isidis and Hellas, centered at longitude 275 degrees, latitude 15 degrees south. A reasonable choice for a tent-town site, as it had long views to the west, and low hills backing it to the east, like moors. But when it came to living in the open air, or growing plants out in the rocky countryside, it was a bit high; in fact it was, if you excluded the very much larger bulges of Tharsis and Elysium, the highest region on Mars, a kind of bioregion island, which the Sabishiians had been cultivating for decades.
They proved to be severely disappointed by the loss of the big mirrors, one might even say thrown into emergency mode, an all-out effort to do what they could to protect the plants of the biome; but it was precious little. Sax’s old colleague Nanao Nakayama shook his head. “Winterkill will be very bad. Like ice age.”
“I’m hoping we can compensate for the loss of light,” Sax said. “Thicken the atmosphere, add greenhouse gases— it’s possible we could do some of that with more bacteria and suralpine plants, right?”
“Some,” Nanao said dubiously. “A lot of niches are already full. The niches are quite small.”
They settled in over a meal to talk about it. All the techs from Da Vinci were there in the big dining hall of The Claw, and many Sabishiians were there to greet them. It was a long, interesting, friendly talk. The Sabishiians were living in the mound maze of their mohole, behind one talon of the dragon figure it made, so that they didn’t have to look at the burned ruins of their city when they weren’t working on it. The rebuilding was much reduced now, as most of them were out dealing with the results of the mirror loss. Nanao said to Tariki, in what was clearly the continuation of a long-standing argument, “It makes no sense to rebuild it as a tent city anyway. We might as well wait, and build it in open air.”
“That may be a long wait,” Tariki said, glancing at Sax. “We’re near the top of the viability atmosphere named in the Dorsa Brevia document.”
Nanao looked at Sax. “We want Sabishii under any limit that is set.”
Sax nodded, shrugged; he didn’t know what to say. The Reds would not like it. But if the viable altitude limit was raised a kilometer or so, it would give the Sabishiians this massif, and make little difference on the larger bulges— so it seemed to make sense. But who knew what they would decide on Pavonis? He said, “Maybe we should focus now on trying to keep atmospheric pressures from dropping.”
They looked somber.
Sax said, “You’ll take us out and show us the massif?”
They cheered up. “Most happy.”
• • •
The land of the Tyrrhena massif was what the areologists in the early years had called the “dissected unit” of the southern highlands, which was much the same as the “cratered unit,” but further broken by small channel networks. The lower and more typical highlands surrounding the massif also contained areas of “ridged unit” and “hilly unit.” In fact, as quickly became obvious the morning they drove out onto the land, all aspects of the rough terrain of the southern highlands were on view, often all at once: cratered, broken, uneven, ridged, dissected, and hilly land, the quintessential Noachian landscape. Sax and Nanao and Tariki sat on the observation deck of one of the Sabishii University rovers; they could see other cars carrying other colleagues, and there were teams out walking ahead of them. On the last hills before the horizon to the east, a few energetic people were fell-running. The hollows of the land were all lightly dusted with dirty snow. The massif was centered fifteen degrees south of the equator, and they got a fair bit of precipitation around Sabishii, Nanao said. The southeast side of the massif was drier, but here, the cloud masses pushed south over the ice in Isidis Planitia and climbed the slope and dropped their loads.
Indeed, as they drove uphill great waves of dark cloud rolled in from the northwest, pouring over them as if chasing the fell-runners. Sax shuddered, remembering his recent exposure to the elements; he was happy to be in a rover, and felt he would need only short walks away from it to be satisfied.
Eventually, however, they stopped on a high point in a low old ridge, and got out. They made their way over a surface littered with boulders and knobs, cracks, sand drifts, very small craters, breadloafed bedrock, scarps and alases, and the old shallow channels that gave the dissected unit its name. In truth there were deformational features of every kind to be seen, for the land here was four billion years old. A lot had happened to it, but nothing had ever happened to destroy it completely and clean the slate, so all four billion years were still there to be seen, in a veritable museum of rockscapes. It had been thoroughly pulverized in the Noachian, leaving regolith several kilometers deep, and craters and deformities that no aeolian stripping could remove. And during this early period the other side of the planet had had its lithosphere to a depth of six kilometers blasted into space by the so-called Big Hit; a fair amount of that ejecta had eventually landed in the south. That was the explanation for the Great Escarpment, and the lack of ancient highlands in the north; and one more factor in the extremely disordered look of this land.