The woman curled a meter or so of her centipedelike body away from her station, holding position with her last live pairs of climbing legs and bringing her eyes toward Molly. “I think I can manage, thanks. I’ll be sure by about halfway through the next shift and will be very glad of any help you can give, if it proves to be needed then. Thanks for the offer.”
“How about you, Carol?”
“No problems, thanks. I’ll be able to help with Joe’s machines after next shift.”
“Thank you all,” said Joe. “I am personally grateful, of course, and probably should remind all of us that we are a i cam and should all be completely familiar with all procedures and equipment anyway. The process of mutual help will move us in this direction, of course, but any apparatus anyone does not understand by the time we reach Enigma will have to be very familiar before we start work there—understood by everyone. The time taken to achieve this will have to come out of the hours we have on the planet, or i he time before we reach it. The latter seems preferable to me.”
“Good point,” conceded Charley. “I’ll help with your wind-trackers, too, as soon as Molly’s gear is on board here.”
The others expressed agreement, less hastily than the Kantrick, and they waited with their varying levels of patience for the acceleration warning.
Enigma became visible during the next watch, and by the time Molly was back on Con duty, the little world could be seen in some detail. The only trouble was that there were no real details to see. Its surface was largely hidden by a blanket of cloud, though not quite as completely as those of Venus and Titan in her own system. The veil glowed even whiter than that of the former planet in the glare of Arc and its companion. Neither the clouds nor their gaps provided patterns that offered meaning to the Human mind.
That, she reminded herself, was in what she considered proper lighting. The atmosphere—obviously there was one—could be supporting clouds of water or ammonia droplets, solid crystals of either substance, or light-colored dust—really light-colored; salts of alkali or alkaline-earth metals, possibly silica or rutile, but, except for the last, probably nothing from the transition metal part of the table that would absorb what to her was visible light. She shifted her instrument through the spectrum experimentally to see whether any albedo features might show at other wavelengths. There was some streakiness in the ultraviolet that reminded her of Venus in the same range, but interpreting this as wind was probably premature. A little work indicated that the cloud tops were at a temperature of about two hundred Kelvin, moderately comfortable for most of her friends but too cold to narrow down the chemical possibilities for the clouds themselves.
She cut off her screen and sat back to think.
“I tried a Doppler display, Molly.” It was Jenny’s harsh voice; the Rimmore woman was on watch instead of Joe, who was still manufacturing wind-robots. She was as diffident as the Nethneen about interrupting someone at work, but less likely to interpret physical inactivity as mental labor.
“Docs it suggest anything? May I look?” asked Molly.
“I was hoping you would. I think so.” Jenny keyed her monitor controls to the general output circuits, and the other woman shifted hers to take the picture. She had to modify the presentation colors, of course, but this took only a few seconds, and once she had a visible image she could see immediately that the other had some useful information.
“It is wind—I thought it might be from the cloud pattern.”
“I’ve had practice with this,” replied the Rimmore. “There’s one big difference between Ivory and Hrimm, you know. Ivory has decent gravity and general temperature, and even a breathable atmosphere…”
“Yes. There aren’t many people at the School who can walk around on one of its planets with no environment armor. But what’s the difference?”
“Climate—that is, the way weather changes with time. At home on Hrimm, the equatorial and orbital planes are only fifteen degrees apart, and Hrimm rotates in about eighteen hours. Ivory has a forty-degree inclination and a thirty-seven-hour rotation. Air circulation is simply weird, and I did a lot of work on it, both from the surface and from space.”
“Good for you, Jen. There’s some more work to be done here, but I’d guess offhand that this place has seasons. The rotation axis is somewhere near there, the end toward us out of sunlight, the one having winter. Does your world have seasons of that sort?”
“Yes.”
“Then I’d say you’re picking up high-altitude winds from the winter hemisphere to the summer one, running two or three hundred kilometers an hour at the cloud tops. Cool air would be—hey, that doesn’t make sense. High circulation ought to be the other way, shouldn’t it?”
“I would have thought so.” Jenny shifted sinuously at her station, her iridescent scales shimmering through her transparent air-suit.
“Rotation is—let’s see—by my criteria, the northern hemisphere is having summer now. We’ll need more orbit data to see how long it’s been so and how much longer it will be. As I remember size, rotation must be—no, forget that. There’s no way to tell how much of the east-west component of those winds can be credited to the solid planet.”
“Not until we have surface imaging,” agreed Jenny. “There are some old maps available, as I recall the original notes we were given. Radar ones from space; anything students did on the surface in earlier exercises has been sealed, 1 suppose.”
“So Charley insists.” Molly thought for a moment. “We’d better call up the orbit data; we’re going to have to think about seasons here. Surely they haven’t sealed that—it’s information anyone could get in seconds with ordinary navigation equipment.”
“They may expect us to get it from the student crew,” Jenny pointed out, “and sealed it from them.”
Molly nodded absently and played with her console. The other woman followed on her own screen. Both made gestures equivalent to a head nod as the requested information appeared. The Faculty was not expecting them to waste time, it seemed.
“Good,” rasped Jenny. “Very slow rotation—about twenty-three days.” Molly started to glance at the clock, then remembered that the translator would have turned whatever the Rimmore had actually said into her own days. “Nothing to affect our Doppler wind reading seriously. Joe will want this; it will help him plan the initial setup of his air-current monitors.”
“Right,” agreed Molly. “You’d better do the saving—it was your idea, and I’m likely to pick colors he couldn’t distinguish on the display. I’ll be looking for records of surface structure; someone must have given it a going over in radar.”
“We can do that ourselves.”
“Not from here, with any decent resolution. We will if we have to when we get close in.”
“We’d better anyway. Surfaces change,” Molly agreed absently; she was already keying through records for anything there might be about Enigma’s topography. It was a young planet, of course; it had to be—stars like Arc and its companion were too massive and luminous to last more than a million years or two. The surprising thing was that a planet existed at all; material that had not been incorporated into the two stars should still have been in the form of proto-planetary junk, and most of that should by rights be ejected from the binary system before it ever managed to coalesce.
No other planets. Correction: no record of other known planets. Probably a safe datum; from Enigma’s well-lit neighborhood forty-odd astronomical units from Arc, anything of decent size would be clearly visible even against a rich star background. Not even Charley would suggest that such records would have been sealed to make a more complex exercise for future students.