Europa Strike(42)
Forested Areas: 10%; Plain, Savannah, or Veldt: 5%;
Other: 4%; No polar ice caps or extensive glaciation evident; No appreciable seasonal snowfall save at extreme elevations; Cloud cover: Approximately 50%;
Albedo: 0.26; Mean surface referent temperature: 39° C.
Atmosphere
Pressure: 515 mm Hg = .678 bar
Composition: N2 74.97%; O2’ 22.43% (partial pressure O2 = 15.2%); Ar, 1.54%; H2O,.1-2.1% (mean 1.0%);
CO2: 466 ppm; Ne, 59.7 ppm; He, 7.87 ppm;
Other: ‹ 7 ppm
The facts and figures scarcely embraced a world, however. Chiron—the world, inevitably, had been named after the centaur in Greek myth who’d been the teacher of Aesclepius the Healer—was mostly desert and arid mountain, with scattered, shallow seas and vast salt flats indicating that those seas once had been larger. The atmosphere was thin, though the oxygen levels were high enough that the PPO2 would have allowed humans to breathe on the surface without artificial assistance. The world was scarcely inviting by human standards, however. Though slightly farther from its primary than Earth was from Sol, Chiron circled a star almost half again as bright than Earth’s sun. The base temperature was 37 degrees, considerably warmer than humans liked it—though the polar regions and higher elevations were temperate, and in winter might even see a few, brief snowfalls.
And, in human terms, the scenery was spectacular. The colors were all gold and red, the result of a chlorophyll analogue that colored the vegetation in reddish and yellow hues. More heat and faster rotation than Earth meant more powerful storms. A more energetic sun, stronger magnetic field, and faster rotation meant more spectacular auroras illuminating the night. And there was always Alpha Centauri B, the second component of the double sun system, which every eighty years came within eleven astronomical units—not enough to add more than a few degrees to the planet’s base temperature, but close enough to shine even in the daytime sky as a brilliant orange-white beacon, and to cast light enough at night to read by easily.
At the moment, B was approaching periastron, 35 AU out. The orange star had apparently truncated A’s fledgling solar system early in its history—Alpha Centauri A possessed only three planets, the outermost a small gas giant just 1.9 AU out. Any outer worlds must have been flung into interstellar space billions of years ago by the perturbations of the dual-sun complex. B had a miniature solar system of its own as well, two worlds—a gas giant the size of Neptune, and an airless Mercurian rock.
But so much had been observed twelve years ago by Farstar and other telescopic efforts from Earth’s solar system. A. What had attracted human interest in Alpha Centauri A II had been the Chironian Ruins.
They were scattered across the arid surface of the world like the salt encrustations along the shores of the dying seas—tens of thousands of square kilometers of them, remnants of cities constructed with truly cyclopean magnificence, smashed and blasted and tumbled-down, now, in an all-encompassing devastation suggesting apocalypse on a planetary scale.
Farstar and the other Sol-system telescopes had mapped large parts of those labyrinthine ruins, though that was an ongoing task that would take another century at least to complete. Those distant eyes could not peer through earth, rock, and fallen masonry, however, nor could they see through the towering thunderheads that frequently obscured the Chironian coastal regions. A closer inspection was necessary, and that was Ad Astra’s primary mission.
Sam Too had in one sense divided herself, her awareness, in two. The main part of her consciousness continued to reside within the Ad Astra as it orbited Chiron, circling the golden world once every 200 minutes.
However, she was also in close laser and radio communications contact with Oscar, one of three ranger probes carried in external cradles slung from the Ad Astra’s spine. With the other two probes in reserve, Oscar had been deorbited hours earlier, dropped into a meteoric entry vector that had scratched white fire across the Chironian night and now, hours later, was down in the general vicinity of a particular landmark called the Needle.
While a small part of Sam Too’s awareness was now resident in the computers on board Oscar, what was there was capable of only about 1012 cps and was not in any way self-aware. Most of Sam remained with the Ad Astra, maintaining the linkage even when the spacecraft dropped below Oscar’s horizon by a constellation of communications satellite strung along the ship’s orbital path like beads on a string.
An important principle of sensory psychology insisted that it didn’t matter how long the data input path was, whether it was the few inches of the human optic nerve leading to the brain, or a lasercom-and-relay sat connection across thousands of kilometers. Through the teleoperational link, Sam was there as Oscar picked its way across the rubble-strewn landscape. She could see the play of golden light across the thunderheads on the eastern horizon, as Alpha A rose in dazzling yellow splendor, feel the hot, thin breeze, hear the shriek of Oscar’s jets.