by Hal Clement
“And that, I think, is that. I want to go back to Earth and get a new spectrograph. I’ll have to do all my work over again, blast it; I forgot to remove my plates from the machine before we closed the circuit.”
1956
DUST RAG
It has been said before that the little things in life are what count. The big things about living on another world are easy to predict; it’s the petty nuisances . . . that are deadly!
“Checking out.”
“Checked, Ridge. See you soon.”
Ridging glanced over his shoulder at Beacon Peak, as the point where the relay station had been mounted was known. The gleaming dome of its leaden meteor shield was visible as a spark; most of the lower peaks of Harpalus were already below the horizon, and with them the last territory with which Ridging or Shandara could claim familiarity. The humming turbine tractor that carried them was the only sign of humanity except each others’ faces—the thin crescent of their home world was too close to the sun to be seen easily, and Earth doesn’t look very “human” from outside in any case.
The prospect ahead was not exactly strange, of course. Shandara had remarked several times in the last four weeks that a man who had seen any of the moon had seen all of it. A good many others had agreed with him. Even Ridging, whose temperament kept him normally expecting something new to happen, was beginning to get a trifle bored with the place. It wasn’t even dangerous; he knew perfectly well what exposure to vacuum would mean, but checking spacesuit and air-lock valves had become a matter of habit long before.
Cosmic rays went through plastic suits and living bodies like glass, for the most part ineffective because unabsorbed; meteors blew microscopic holes through thin metal, but scarcely marked spacesuits or hulls, as far as current experiences went; the “dust-hidden crevasses” which they had expected to catch unwary men or vehicles simply didn’t exist—the dust was too dry to cover any sort of hole, except by filling it completely. The closest approach to a casualty suffered so far had occurred when a man had missed his footing on the ladder outside the Albireo‘s air lock and narrowly avoided a hundred and fifty foot fall.
Still, Shandara was being cautious. His eyes swept the ground ahead of their tracks, and his gauntleted hands rested lightly on brake and steering controls as the tractor glided ahead.
Harpalus and the relay station were out of sight now. Another glance behind assured Ridging of that. For the first time in weeks he was out of touch with the rest of the group, and for the first time he wondered whether it was such a good idea. Orders had been strict; the radius of exploration settled on long before was not to be exceeded. Ridging had been completely in favor of this; but it was his own instruments which had triggered the change of schedule.
One question about the moon to which no one could more than guess an answer in advance was that of its magnetic field. Once the group was on the surface it had immediately become evident that there was one, and comparative readings had indicated that the south magnetic pole—or a south magnetic pole—lay a few hundred miles away. It had been decided to modify the program to check the region, since the last forlorn chance of finding any trace of a gaseous envelope around the moon seemed to lie in auroral investigation. Ridging found himself, to his intense astonishment, wondering why he had volunteered for the trip and then wondering how such thoughts could cross his mind. He had never considered himself a coward, and certainly had no one but himself to blame for being in the tractor. No one had made him volunteer, and any technician could have set up and operated the equipment.
“Come out of it, Ridge. Anyone would think you were worried.” Shandara’s careless tones cut into his thoughts. “How about running this buggy for a while? I’ve had her for a hundred kilos.”
“Right.” Ridging slipped into the driver’s seat as his companion left it without slowing the tractor. He did not need to find their location on the photographic map clipped beside the panel; he had been keeping a running check almost unconsciously between the features it showed and the landmarks appearing over the horizon. A course had been marked on it, and navigation was not expected to be a problem even without a magnetic compass.
The course was far from straight, though it led over what passed for fairly smooth territory on the moon. Even back on Sinus Rods the tractor had had to weave its way around numerous obstacles; now well onto the Mare Frigoris the situation was no better, and according to the map it was nearly time to turn south through the mountains, which would be infinitely worse. According to the photos taken during the original landing approach the journey would be possible, however, and would lead through the range at its narrowest part out onto Mare Imbrium. From that point to the vicinity of Plato, where the region to be investigated lay, there should be no trouble at all.
Oddly enough, there wasn’t. Ridging was moderately surprised; Shandara seemed to take it as a matter of course. The cartographer had eaten, slept, and taken his turn at driving with only an occasional remark. Ridging was beginning to believe by the time they reached their goal that his companion was actually as bored with the moon as he claimed to be. The thought, however, was fleeting; there was work to be done.
About six hundred pounds of assorted instruments were attached to the trailer which had been improvised from discarded fuel tanks. The tractor itself could not carry them; its entire cargo space was occupied by another improvisation—an auxiliary fuel tank which had been needed to make the present journey possible. The instruments had to be removed, set up in various spots, and permitted to make their records for the next thirty hours. This would have been a minor task, and possibly even justified a little boredom, had it not been for the fact that some of the “spots” were supposed to be as high as possible. Both men had climbed Lunar mountains in the last four weeks, and neither was worried about the task; but there was some question as to which mountain would best suit their needs.
They had stopped on fairly level ground south and somewhat west of Plato—“sunset” west, that is, not astronomical. There was a number of fairly prominent elevations in sight. None seemed more than a thousand meters or so in height, however, and the men knew that Plato in one direction and the Teneriffe Mountains in the other had peaks fully twice as high. The problem was which to choose.
“We can’t take the tractor either way,” pointed out Shandara. “We’re cutting things pretty fine on the fuel question as it is. We are going to have to pack the instruments ourselves, and it’s fifty or sixty kilometers to Teneriffe before we even start climbing. Plato’s a lot closer.”
“The near side of Plato’s a lot closer,” admitted Ridging, “but the measured peaks in its rim must be on the east and west sides, where they can cast shadows across the crater floor. We might have to go as far for a really good peak as we would if we headed south.”
“That’s not quite right. Look at the map. The near rim of the crater is fairly straight, and doesn’t run straight east and west; it must cast shadows that they could measure from Earth. Why can’t it contain some of those two thousand meter humps mentioned in the atlas?”
“No reason why it can’t; but we don’t know that it does. This map doesn’t show.”
“It doesn’t show for Teneriffe, either.”
“That’s true, but there isn’t much choice there, and we know that there’s at least one high peak in a fairly small area. Plato is well over three hundred kilometers around.”
“It’s still a closer walk, and I don’t see why, if there are high peaks at any part of the rim, they shouldn’t be fairly common all around the circumference.”
“I don’t see why either,” retorted Ridging, “but I’ve seen several craters for which that wasn’t true. So have you.” Shandara had no immediate answer to this, but he had no intention of exposing himself to an unnecessarily long walk if he could help it. The instruments to be carried were admittedly light, at least on the moon; but there would be no chance of opening spacesuits until the men got back to the tractor, and spacesuits go
t quite uncomfortable after a while.
It was the magnetometer that won Shandara’s point for him. This pleased him greatly at the time, though he was heard to express a different opinion later. The meter itself did not attract attention until the men were about ready to start, and he had resigned himself to the long walk after a good deal more argument; but a final check of the recorders already operating made Ridging stop and think.
“Say, Shan, have you noticed any sun spots lately?”
“Haven’t looked at the sun, and don’t plan to.”
“I know. I mean, have any of the astronomers mentioned anything of the sort?”
“I didn’t hear them, and we’ll never be able to ask until we get back. Why?”
“I’d say there was a magnetic storm of some sort going on. The intensity, dip, and azimuth readings have all changed quite a bit in the last hour.”
“I thought dip was near vertical anyway.”
“It is, but that doesn’t keep it from changing. You know, Shan, maybe it would be better if we went to Plato, instead.”
“That’s what I’ve been saying all along. What’s changed your mind?”
“This magnetic business. On Earth, such storms are caused by charged particles from the sun, deflected by the planet’s magnetic field and forming what amounts to tremendous electric currents which naturally produce fields of their own. If that’s what is happening here, it would be nice to get even closer to the local magnetic vertical, if we can; and that seems to be in, or at least near, Plato.”
“That suits me. I’ve been arguing that way all along. I’m with you.”
“There’s one other thing—”
“What?”
“This magnetometer ought to go along with us, as well as the stuff we were taking anyway. Do you mind helping with the extra weight?” Shandara had not considered this aspect of the matter, but since his arguments had been founded on the question of time rather than effort he agreed readily, to the additional labor.
“All right. Just a few minutes while I dismount and repack this gadget, and we’ll be on our way.” Ridging set to work, and was ready in the specified time, since the apparatus had been designed to be handled by spacesuited men. The carrying racks that took the place of regular packs made the travelers look top-heavy, but they had long since learned to keep their balance under such loads. They turned until the nearly motionless sun was behind them and to their right, and set out for the hills ahead.
These elevations were not the peaks they expected to use; the moon’s near horizon made those still invisible. They did, however, represent the outer reaches of the area which had been disturbed by whatever monstrous explosion had blown the ring of Plato in the moon’s crust. As far as the men were concerned, these hills simply meant that very little of their journey would be across level ground, which pleased them just as well. Level ground was sometimes an inch or two deep in dust; and while dust could not hide deep cracks it could and sometimes did fill broader hollows and cover irregularities where one could trip. For a top-heavy man, this could be a serious nuisance. Relatively little dust had been encountered by any of the expedition up to this point, since most of their work had involved slopes or peaks; but a few annoying lessons had been learned.
Shandara and Ridging stuck to the relatively dust-free slopes, therefore. The going was easy enough for experienced men, and they traveled at pretty fair speed—some ten or twelve miles an hour, they judged. The tractor soon disappeared, and compasses were useless, but both men had a good eye for country, and were used enough to the Lunar landscape to have no particular difficulty in finding distinctive features. They said little, except to call each other’s attention to particularly good landmarks.
The general ground level was going up after the first hour and a half, though there was still plenty of downhill travel. A relatively near line of peaks ahead was presumably the crater rim; there was little difficulty in deciding on the most suitable one and heading for it. Naturally the footing became worse and the slopes steeper as they approached, but nothing was dangerous even yet. Such crevasses as existed were easy both to see and to jump, and there are few loose rocks on the moon.
It was only about three and a half hours after leaving the tractor, therefore, that the two men reached the peak they had selected, and looked out over the great walled plain of Plato. They couldn’t see all of it, of course; Plato is a hundred kilometers across, and even from a height of two thousand meters the farther side of the floor lies below the horizon. The opposite rim could be seen but there was no easy way to tell whether any of the peaks visible there were as high as the one from which the men saw them. It didn’t really matter; this one was high enough for their purposes.
The instruments were unloaded and set up in half an hour. Ridging did most of the work, with a professional single-mindedness which Shandara made no attempt to emulate. The geophysicist scarcely glanced at the crater floor after his first look around upon their arrival, while Shandara did little else. Ridging was not surprised; he had been reasonably sure that his friend had had ulterior reasons for wanting to come this way.
“All right,” he said, as he straightened up after closing the last switch, “when do we go down, and how long do we take?”
“Go down where?” asked Shandara innocently.
“Down to the crater floor, I suppose. I’m sure you don’t see enough to satisfy you from here. It’s just an ordinary crater, of course, but it’s three times the diameter of Harpalus even if the walls are less than half as high, and you’ll surely want to see every square meter of the floor.”
“I’ll want to see some of the floor, anyway.” Shandara’s tone carried feeling even through the suit radios. “It’s nice of you to realize that we have to go down. I wish you realized why.”
“You mean . . . you mean you really expect to climb down there?” Ridging, in spite of his knowledge of the other’s interests, was startled. “I didn’t really mean—”
“I didn’t think you did. You haven’t looked over the edge once.”
Ridging repaired the omission, letting his gaze sweep carefully over the grayish plain at the foot of the slope. He knew that the floor of Plato was one of the darker areas on the moon, but had never supposed that this fact constituted a major problem.
“I don’t get it,” he said at last. “I don’t see anything. The floor is smoother than that of Harpalus, I’d say, but I’m not really sure even of that, from this distance. It’s a couple of kilos down and I don’t know how far over.”
“You brought the map.” It was not a question.
“Of course.”
“Look at it. It’s a good one.” Ridging obeyed, bewildered. The map was good, as Shandara had said; its scale was sufficient to show Plato some fifteen centimeters across, with plenty of detail. It was basically an enlargement of a map published on Earth, from telescopic observations; but a good deal of detail had been added from photographs taken during the approach and landing of the expedition. Shandara knew that; it was largely his own work.
As a result, Ridging was not long in seeing what his companion meant. The map showed five fairly large craterlets within Plato, and nearly a hundred smaller features.
Ridging could see none of them from where he stood.
He looked thoughtfully down the slope, then at the other man.
“I begin to see what you mean. Did you expect something like this? Is that why you wanted to come here? Why didn’t you tell me?”
“I didn’t expect it, though I had a vague hope. A good many times in the past, observers have reported that the features on the floor of this crater were obscured. Dr. Pickering, at the beginning of the century, thought of it as an active volcanic area; others have blamed the business on clouds—and others, of course, have assumed the observers themselves were at fault, though that is pretty hard to justify. I didn’t really expect to get a chance to check up on the phenomenon, but I’m sure you don’t expect me to stay up here now.”
“I suppose not.” Ridging spoke in a tone of mock resignation. The problem did not seem to concern his field directly, but he judged rightly that the present situation affected Shandara the way an offer of a genuine fragment of Terrestrial core material would influence Ridging himself. “What do you plan to take down? I suppose you want to get measures of some sort.”
“Well, there isn’t too much here that will apply, I’m afraid. I have my own camera and some filters, which may do some good. I can’t see that the magnetic stuff will be any use down there. We don’t have any pressure measuring or gas collecting gadgetry; I suppose if we’d brought a spare water container from the tractor we could dump it, but we didn’t and I’d bet that nothing would be found in it but water vapor if we did. We’ll just have to go down and see what our eyes will tell us, and record anything that seems recordable on film. Are you ready?”
“Ready as I ever will be.” Ridging knew the remark was neither original nor brilliant, but nothing else seemed to fit.
The inner wall of the crater was a good deal steeper than the one they had climbed, but still did not present a serious obstacle. The principal trouble was that much of the way led through clefts where the sun did not shine, and the only light was reflected from distant slopes. There wasn’t much of it, and the men had to be careful of their footings—there was an occasional loose fragment here, and a thousand-meter fall is no joke even on the moon. The way did not lead directly toward the crater floor; the serrated rim offered better ways between its peaks, hairpinning back and forth so that sometimes the central plain was not visible at all. No floor details appeared as they descended, but whatever covered them was still below; the stars, whenever the mountains cut off enough sidelight, were clear as ever. Time and again Shandara stopped to look over the great plain, which seemed limitless now that the peaks on the farther side had dropped below the horizon, but nothing in the way of information rewarded the effort.
