by Hal Clement
“All right.”
“Hold it!” It was Gene, of course. “If visibility goes down too far, how do you keep track of direction?”
“You can be observed and guided from the jet,” the computer pointed out. There could have had been no insult intended in its use of “you” rather “she”, but Belvew felt snubbed just the same.
“I’ve started,” was Maria’s only comment.
A human being fully equipped with environment gear can make a standing broad jump of four or five meters on Titan, if he doesn’t care which way up he lands. A walker reasonably careful about keeping helmet upward and at least one foot fairly near the ground will take nearly a second to make a one-meter stride. This is about four kilometers an hour, considerably less than the speed of a healthy young adult on Earth. This is not in spite of the gravity on the satellite, but because of it. There were now few healthy young adults on Earth, and still fewer on Titan, but Maria could make reasonable speed by her colleagues’ standards.
By the time Ginger had finished laying the seismic detectors, therefore, Maria was nearing what Seichi had described as the west edge of the “cloud.” By this time she felt sure, and had reported, that it consisted of solid particles far too small to see individually, but large enough to settle fairly quickly even here. They now formed a layer two or three centimeters deep under her feet, hiding the smog sediment which might have extended for as much deeper, or a whole meter, or fifty meters, or not been there at all. Its thickness, they now knew, varied widely over Titan’s surface. It had been moved—drifted?—extensively, settling very slowly as ultrafine dust. Even Titan’s negligible winds could move it easily until it finally caked in the methane rains.
The most reasonable guess at the white stuff’s identity was water ice, but no one had suggested a plausible origin for it. This was only partly because of earlier experience with other white powders observed to freeze on wings.
Ginger, her run finished, was flying perhaps imprudently low along the west edge of the cloud, but could make out no real details. It was Maria who got the first good enough look at the source to feed hungry imaginations.
She could not, afterward, deny that there had been some warning. A gradually increasing roar which she had unthinkingly attributed to Theia, and a steady, faint quivering of the surface underfoot which she soon tuned out should have alerted her.
Almost suddenly, within the space of a few steps, she found herself seeing the familiar near-orange sky in all directions overhead. The dense white fog now reached only to her shoulders, swirling gently around her body in what passed for a high wind here; thinner, more transparent fluff still reached several meters above her, but she could see a horizon of sorts. A few meters ahead, beyond the drifting white, the ground showed in its usual smog color, about the same tint as the sky but much darker except where bare patches of ice were exposed. None of the “pools” was in sight.
Her eyes had just registered that the surface ahead was lower than the one she was walking on when her feet made the same discovery. She stepped over the edge of another fault.
The fall would have been only about a meter if she had simply fallen. Instead, she was hurled upward by a blast of wind; not violently and not far before starting down, but she made an almost complete back somersault, landing mostly on her shoulders on a bare patch of ice. Her helmet took some of the impact, and for a moment she felt a terrifying chill which was fortunately subjective.
She brought herself upright with a push of her left hand and looked around.
She had left the vision-hampering cloud. Westward, as she had seen before stepping over the edge, the bare ground extended to the crater wall half a kilometer away. To the east was a smooth vertical step a meter or so high, whose face was almost totally hidden by roiling streams of white which spewed, also vertically, from a narrow crack at its base. Maria started to approach it, remembered the upward kick, became conscious of the roar, and stopped to report before getting any closer.
“I’m out of the cloud, Ginger. Can you see me? There’s another fault here, open, with something blowing up at its edge. It’s the cloud source, I’d say. My best guess is still ice dust, but we need labs here pronto.”
“I’m a couple of minutes north of the rim, too far to see you. I still have labs aboard; I left only one at the new patch. How many should I drop?”
“I’d say two—one just inside the cloud, one on my side of the edge. There’s a fair amount of snow, if that’s what the white stuff is, on the ground to the east; it shouldn’t take long to get samples. This side looks like ordinary titan, but we’d better make sure.” The commander stopped talking and listened.
“Coming around, five hundred up . . . I see you. I’ll slow down as much as I can. The labs don’t have parachutes—should I land and plant them properly?”
“Take a chance with them from where you are,” Belvew advised. “They’re more replaceable than Theia.”
The commander agreed, adding, “Don’t get down too close to stall—any kind of stall—and don’t get below five hundred. There’s an updraft at the fault strong enough to pick me up. Drop to the west; that’s into what wind there is and will take a little from the impact’s horizontal component, at least.”
“All right.” The commander watched the jet bank overhead and thunder eastward over the whiteness. Its deeper sound, she now realized, could easily be distinguished from the whistle of gas from the crevice. After dwindling for a minute it swung back, heading not exactly toward her but a little to her left.
“I don’t suppose there’s much chance of damaging you with either of these,” the pilot said conventionally, “but let’s plan for a clear miss.”
“I could dodge, or shelter near the cliff, but thanks for the thought. Are you dropping on this pass?”
“Yes.” The craft swelled in the commander’s field of vision and the thunder of its ramjets made parts of Maria’s suit vibrate. Ginger was not risking a stall even of the pipes, much less the wings, and of course didn’t want to waste mass by using rocket mode. The commander saw the two black dots separate from the hull scarcely a second apart; the pilot seemed to have confidence in her bombing skill. This proved justified. The first lab vanished into the cloud sixty or seventy meters east of the step, and the second struck a little farther from the fault than Maria was standing. It rolled to a stop about fifty meters northwest of her. She moved quickly toward it and watched with relief as it extended its sampling appendages and got to work.
“Someone read those as fast as you can, especially the one in the snow,” she ordered.
“I’m handling it,” came the voice of Cheru Asagewa, who was gradually working his way into Goodell’s former jobs. “It’ll be a few minutes at least.”
“Right. If it’s something weird like the vinyl in the pools let’s find out the first time.” The voice, to the surprise of some, was Ginger’s rather than Gene’s.
“Commander, can you provide more data on this cloud-emitting fault?” queried Status. “It is impossible so far to set up a coherent picture. Specifically, can you judge the width of the opening and flow rate of the escaping gas?”
“I’ll try. It was fast enough to lift me, though not very far. If Ginger will measure the wind, I, or you, may be able to figure out something from how high the stuff rises before it gets blown east.”
“All right. That’ll be a few minutes, too,” replied the pilot. Maria stood still; she was presumably the most visible small surface object in the area, and Ginger might want to use her as a reference marker. Even if she didn’t, moving was becoming hard work; another spell of fatigue was approaching, she could tell. It didn’t matter much; she could examine the fault from where she stood.
“The crack at the foot of the step is very narrow, not more than a millimeter or two,” she reported. “Right where it opens, the cloud is too dense to let me see through it, except in glimpses. A few centimeters higher it thins out, and I can see turbulence in the gas currents.”<
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“What’s the face of the scarp show?” asked Seichi.
“Plain ice up to about seventy-five centimeters, then smog sediment, then a couple of centimeters of white—I suppose the same stuff that makes the cloud. Cheru, when you get a chance walk the lab that’s in the cloud eastward—no, forget it. I’ll pick up the other and put it on the top at the edge.”
Not even Belvew remembered the updraft soon enough. Maria herself was not lifted this time, but felt the trivial weight of the spheroid she was carrying disappear as she was about to place it on the white rim. A moment later she gave a grunt of surprise, which naturally produced a response from Gene.
“What’s happening?”
“More trivia,” was the calm answer. “The lab was lifted out of my hand as I started to put it through the cloud. Now it’s bobbing around in the air about six or eight centimeters above the cliff and about a meter to the right of where I was reaching in. It’s oscillating about ten centimeters each way north and south, about three east and west and about the same up and down. I’ve seen that sort of thing before, of course; I just wasn’t expecting it.”
“What? Oh, Bernoulli effect.” Belvew’s pilot experience responded to the description. “Status, there’s the information you need about the updraft speed. You know the mass, area, and shape of the lab.”
“I will have to assume the gas density is the same as that of the general atmosphere,” the robot pointed out. “It probably is, that far above the vent, if the commander is right about the turbulence. She has just over twenty hours to suit emergency status; she has been using more oxygen than usual.”
No one was particularly surprised at Status’ sudden change of subject. The processor’s top priority was the physical status of the team members.
“Thank you,” Maria acknowledged. “Cheru, should I put the lab in the snow, or leave it where it is while you run a gas analysis.”
“Gas by all means. That’ll let us check Status’ guess. I have some readings from the other lab now, but I don’t understand them all.”
“What’s the trouble?” came several voices.
“The elements in the white stuff are hydrogen and oxygen and nothing else. It should be water, ice I at this pressure, but shows no crystal structure at all. There’s just a diffraction blur corresponding to H-O bond length—”
“How about oxygen-oxygen?” again several voices sounded almost at once.
“It is not hydrogen peroxide. No O-O bonds. I said it showed no structure, like a liquid or a gas.” The chemist’s tone, and even his voice, for a moment took on a surprising similarity to those of Arthur Goodell; once again Maria felt a chill not due to her surroundings.
“You have no ideas right now,” she said, trying to keep any questioning intonation out of her voice.
“Not right now. I’m running the gas check now. Do you need that, or shall I just file it with Status?”
“File it.” Maria made another quick decision. “I should be doing something besides listening. Status, will it be better for me to go back to digging, or should I explore along this new fault? My guess is that it would be better to let you build pictures from the new seismic lines before we run that tunnel any deeper.”
“The fault can be mapped adequately from above,” the processor answered promptly. “The cliff in which we started the tunnel is now partly obscured by the cloud, and it would be valuable to check any of its recent changes. We have reason to believe now that these may be very rapid. I suggest you go back to the east but make no attempt to seek the tunnel itself. You still have the digger, I believe. Rather, bear to the south—”
“Why not the north? Wouldn’t the region of the crater rim give us more information?”
“It probably would, but that would take you farther from any practical landing area, especially if the cloud continues to move eastward. I have just reminded you of the limitations of your suit.”
“You don’t think the information would be worth the risk?”
“No.” The answer was in Status’ calm voice; Belvew, to the surprise of the commander and several others, said nothing.
“All right. Ginger, have you had time to make the wind check? Is it all right for me to move?”
“I wasn’t using you. There are places along the fault where there are fountains, if that’s the word I want—anyway, the stuff isn’t blowing up equally high everywhere, so I had plenty of reference points; and for one component I dopplered on the cliff face. Your wind is seventy-one point one centimeters a second from two-eighty-four absolute.”
“All right. Status, you can fit that in. I’m jumping the face—I’m being careful, Gene—and heading southeast. Ginger, get whatever Status asks for that you can manage without risking the plane. Between its requests, just map. Pete, track me. There’s no profit in my walking around in circles. There must be some radiation that can see through this stuff—after all, I was never out of talk contact.”
“Right, boss. Any reading will take a minute or two; I’ll have to average half a dozen. If you want a direction it’ll take even longer, but I don’t think there’s any chance of losing you.”
“Neither does Status, apparently, or I’d be sent south around the cloud. I won’t need direction for a while; I can look back at my own tracks in the snow and tell whether I’m circling.”
“Have you checked that, or is it theory?” asked Belvew.
“I’m checking it now. It seems to work.”
“Your tracks aren’t being blown out by the wind?”
“Not for as far back as I can see.”
“Which is how far?”
“Twenty or thirty meters. That should improve as I get farther from the source and the cloud thins.”
Gene said nothing to this, but Maria was not the only one who realized how the word “should”, which she had carefully not emphasized, was affecting him. She suspected that Martucci was not the only operator tracking her, and hoped Belvew’s regular work wouldn’t suffer.
On Earth, being lost in a blizzard has been deadly to many explorers of the planet’s mountains and pole caps. It has even killed blissfully ignorant people engaged in casual amusement within a few kilometers of safety. Maria Collos was not ignorant and was well over a billion kilometers from anything like a really safe place, but felt no real terror. She didn’t expect to see Earth again anyway; there had been nothing surprising in Barn Inger’s death, nor in Arthur Goodell’s except his own cooperation with it, or any of the earlier ones. There would be nothing surprising in hers when it came, though she hoped this would not be until she had done something else useful—and learned just a little more.
In any case, while she was immersed in a blizzard and could see nothing but blowing whiteness, she did not consider herself lost. Not just yet. Hiking a hundred meters, turning and looking back to see that her trail was straight, and repeating the process for several kilometers was more boring than immediately useful, but every scientist lives with this. Status’ occasional personal report such as “You now have nineteen hours before emergency status” relieved the boredom but was not otherwise helpful. This was also true of the occasional seismic shocks, two of which in the first hour were violent enough to throw her off her feet.
There had to be something odd going on. The area of the first factory had experienced nothing of this sort in the months since its establishment. Barn Inger’s death had occurred there, but could not be blamed on quakes. Goodell’s had occurred here, in Settlement crater, but there was surely no connection—
No. Definitely none. None that Maria Collos could see, or that anyone else had suggested.
The white dust thinned as she drew farther from its source, and the sky started to show a trace of its natural color, though the wind seemed unchanged. The thickness of the white deposit underfoot, determined by scraping down to the substrate with a boot, had decreased to about a centimeter.
Her back, she suddenly noticed, felt warmer than her front. That was odd; the wind was mos
tly from behind her, and if her suit’s temperature-balancing gear wasn’t on the job her back should be colder. Another trivium—perhaps. There was little else to think about, so she considered the problem for a time.
“Radar spots four more faults on the crater floor in the last hour,” came Yakama’s voice. “All of them nearly north and south, with the high side facing west. The tunnel scarp is now half a meter higher.”
“How about the tunnel itself?” asked Maria.
“Can’t tell. No sign of collapse of the region above it. Maybe you should go back north and see.”
“Status? Relative value of such information?”
“Keep on your present track. Changes around the lake and Arthur’s Pool will probably be more important.”
“Have any been seen?”
“The lake’s area has decreased slightly, a little less than one percent. Arthur’s Pool is changing color; its long-wave reflectivity is increasing.”
“His suit hasn’t reappeared, or anything like that, has it?”
“No. It is a change in the general surface, not just a small spot affecting the average. Ginger could fly there in a few seconds, and report what she can see from near at hand.”
“All right.” the pilot did not wait for confirmation. “Maria, you’re keeping direction well enough; you don’t really need either me or Pete.”
“Have you been watching me too? I thought you were mapping the crater.”
“Between times. It wasn’t just radar that spotted the new faults. Status, I can’t see any difference in the lake, but your memory is better than mine. There’s the usual cumulus above it, but no rain at the moment.”
“Can you see Arthur’s Pool?”
“Yes, but the color seems the same to me. Look, all of you use your screens. The whole floor of this crater is acting up. There’s a scarp to the southwest that certainly wasn’t there when I arrived, and one extending a little way from the south rim spitting white stuff like the one Maria just visited. No wonder you’ve been feeling jolts.”
