Clues to the Riddle



            Before Riordan came that evening, I looked over the two sightings Al had cleared. The first Intelligence report covered the rotating lights report which Riordan had mentioned. Though the saucer had been sighted by several air crews and tracked by ground radar, the detailed report was made by Colonel Curtis Low, commander of the fighter escort wing in Japan. (As Colonel Low was mentioned in a news dispatch which briefly described the incident, I am using his right name.)

            The Intelligence officer who interrogated Colonel Low had been seriously impressed by the wing commander's account.

            "The pilot reporting," he said, "has held responsible command assignments for some time. The accuracy of his statements was consistent despite repetitive interrogation. His sequence of times, locations, and descriptions did not vary at any time. He is stable and thoroughly reliable. There were no activities of a meteorological nature or any inversion which could account for these sightings . . . This is a graphic description of an object falling definitely into the family of UFO."

            The action began in the early evening of December 29, 


1952. At about 7:30 p.m. an Air Force radar base in northern Japan received a call from a B-26 crew.

            "We've just sighted a UFO. It looks like a cluster of lights—red, white, and green."

            Moments later the Air Force radar men picked up the UFO. But because of the B-26's low speed, no interception could be made. At 7:45 an F-94 pilot radioed in, reporting the same type of device. The call was overheard by Colonel Low, who was flying his F-84 jet fighter at 27,000 feet

            Three minutes later the wing commander sighted the strange machine, easily identified by its red, white, and green fights. He called Ground Control and was asked to try an interception.

            As he climbed, Colonel Low switched off his lights. The object's lights did not change—proof that it was no canopy reflection. Keeping his own lights off to avoid detection, Low climbed to 35,000 feet. When he got closer, he saw that the saucer's lights were revolving in a counterclockwise direction—a steady rotation between eight and 12 times a minute.

            Beside the shifting colors, Low could see three fixed shafts of white light shining outward. Apparently one part of the machine was rotating, but the change of colors was puzzling. At times the saucer was one solid color, white, green, or red. In between, the wing commander saw brief combinations—red-white, red-green, and green-white. But the three white beams remained constant.

            After watching the device for a moment longer, Colonel Low opened his F-84 to full power. Racing in at over 500 miles an hour, he tried to close the gap. Apparently his unlighted plane was not seen for a second or two. Then the saucer increased its speed. Gradually pulling away, it disappeared in 30 seconds.

            Five minutes later, circling at 35,000 feet, the wing commander saw the machine again. As before, it was at his level, but now moving parallel with the F-84. This time, as a test, Colonel Low left his fights on when he tried to  


close in. Immediately turning west, the strange craft speeded up, so swiftly that it vanished in five seconds.

            Eleven nights later, on January 9, 1953, another machine with similar rotating lights was sighted over Japan and tracked by radar. With the permission of Intelligence, Colonel Low mentioned both cases to war correspondents, withholding the details I have just given.

            "Don't dismiss these as the reports of a few imaginative people," he warned the reporters. "These were corroborated sightings by trained pilots and radar operators."

            When Riordan arrived, I showed him the report.

            "I didn't know about the second case," he said. He read the description again. "These must be a new type—I never heard of them until Colonel Low reported this one."

            "No, they're not new. One was sighted in 1950, over South Dakota. It was tracked by CAA control tower men, and a Weather Bureau observer got a good look with his theodolite. Also it was seen by the crew of an airliner. Then last July an Air Force jet pilot chased one over Michigan, and that same week people in two Michigan counties reported identical saucers—machines with rotating red, green, and white lights."

            "I can't figure that," said Riordan. "What do you make of it?"

            I told him about the rotating-disc theory.

            "It may explain why the lights revolve," I added. "But they must be actual lights, and the same for the fixed white beams—the machine Colonel Low saw didn't show the usual overheating effects. The first time it probably didn't speed up fast enough, and the second time it's possible it disappeared so quickly that he probably wasn't able to notice."

            Riordan stopped to fill his pipe.

            "You know, they might be trying to signal us," he said as he lit up.

            "Maybe. But you'd expect the lights to blink if it was some kind of code." 


            "Unless that combination had some special meaning they're trying to put over."

            "This IR doesn't give any hint of that." I picked up the second ATIC report. "Here's another Japan case. See what you think of it."

            The report, sent in as an IR, had been written in the first person by Lieutenant David C. Brigham, a young Air Force pilot from Rockford, Illinois. It read as follows:

            "At 11:20 hours, March 29, 1952, I was flying a T-6 north of Misawa. GCI was running an intercept on me with a flight of two F-84's. One of them overtook me, passing starboard at approximately 100 feet, and ten feet below me. As he pulled up abreast, a flash of reflected sunshine caught my eye. The object which had reflected the sunshine was a small, shiny disc-shaped object which was making a pass on the F-84.

            "It flew a pursuit curve and closed rapidly. Just as it would have flown into his fuselage, it decelerated to his air speed, almost instantaneously. In doing so, it flipped up on its edge at an approximate 90-degree bank. It fluttered within two feet of his fuselage for perhaps two or three seconds. Then it pulled away around his starboard wing, appearing to flip once as it hit the slipstream behind his wing-tip fuel tank.

            "Then it passed him, crossed in front, and pulled up abruptly, appearing to accelerate, and shot out of sight in a steep, almost vertical climb. It was about eight inches in diameter, very thin, round, and as shiny as polished chromium. It had no apparent projections and left no exhaust or vapor trails. An unusual flight characteristic was a slow, fluttering motion. It rocked back and forth in 40-degree banks, at about one-second intervals throughout its course."

            Riordan put down the report.

            "That beats me," he said. "How the devil could an eight-inch disc fly, let alone maneuver like that?"


            "It could have been spinning and he didn't notice it. It had the typical flutter—"

            "You mean the electromagnetic deal again?"

            "It's the only answer I can think of. The thing must have been a small remote-control observer type."

            "But that little!" protested Riordan.

            "Well, you know we've built some pretty tiny remote-control units for drones and guided missiles. With these new transistors in place of vacuum tubes, they'll be even smaller. And anybody intelligent enough to build flying discs would be way ahead of us."

            "Yes, I guess you're right."

            "If that report gets you," I said, "take a look at these."

            Riordan went through the most dramatic cases, ending with the Gulf of Mexico sighting. His eyebrows shot up when he read the mother ship's final speed.

            "Wow—over 9,000 miles an hour! That's almost unbelievable."

            "I just got another report showing the same thing. It's from an ionosphere observatory—" I showed him the name, which the officials had asked me not to publish. "They track the lower ionosphere layers by radar, and it records any changes on a chart. One night they were tracking the E layer, over 50 miles up, and suddenly the radar picked up a terrific disturbance. The needle jumped all over the chart. Some experts analyzed the tracing later and they said that a solid object, flying a straight course, had passed over the station at between nine and ten thousand miles an hour."

            Riordan shook his head.

            "What's more," I said, "it bears out Smith's theory. The chart showed the ionosphere in a violent commotion, apparently upset by some powerful electrical force. It didn't get back to normal for over 30 minutes, and any air turbulence from the thing's passage should have died down long before that."

            "This business is beginning to worry me," muttered 


Riordan. "I'm absolutely convinced the things are from outer space. But what are they up to?"

            "If anybody knows, I haven't been able to find out. Until lately I've always believed they were friendly. I still think it's an odds-on bet."

            "Just because they haven't attacked us is no proof," Riordan said grimly. "If they're friendly, why haven't they landed?"

            An airliner roared over the house in a low approach to Washington Airport. I waited until it was quiet again.

            "They may not think its safe," I said. "They see our jets trying to intercept the discs—maybe they think we're just naturally hostile."

            "They could radio us and talk it over—say what they want. They must know our language by this time. You told me that this Washington Airport controller, Barnes, thought they heard him talk to the pilots and—" Riordan paused. "Say, I wonder why Barnes didn't try calling them one of those nights."

            "I asked him that. He said there was so much going on he just never thought of it. He told me if he had called, and somebody answered him, his hair would’ve stood on end. Of course, they might not have wanted to reply. I think that's the logical explanation for their silence. Though it's possible they couldn't answer."

            "What do you mean?" demanded Riordan.

            "They may not even talk."

            Riordan stared at me through his pipe smoke.

            "You haven't fallen for that super insect idea? It was in some Englishman's book—"

            "I know—Gerald Heard's Is Another World Watching? No, I don't mean that. But a humanlike race might develop without using audible speech. They might make sounds higher in the spectrum, so that we couldn't hear them. There are such sounds—dogs hear some we don't catch. Or their speech sounds may be so different that they can't  


master our words, even though they might understand the language after studying it a long time."

            There was a silence while Riordan thought it over. Then he grimaced.

            "Somehow, all I can think of is those crazy-looking drawings of Martians. If we knew what planet they come from, it might give us a lead—you think they really could be from Mars?"

            "They may be operating from there, without being Martians. I've collected some educated guesses as to what planet it might be, if it's in our solar system—wait a minute and I'll show you the stuff."

            While I was getting the file, a boat whistle sounded hoarsely from out on the Potomac. Riordan swung his lanky frame around, looked down the hill at the lights of a tug and two barges. He turned back somberly.

            "Things like that make all this business unreal. There's a tug making, say, ten knots, and we sit up here talking about something flying over 9,000 miles an hour."

            "And that 9,000 wouldn't be anything in free space," I said. "Well, here's one item on Mars—it's Project Sign's statement in their April, '49, release. It's short, but it covers the ground. I’ll read you the main points.

            “‘Astronomers are largely in agreement that only one member of the solar system beside earth is capable of supporting life. That is Mars. Even Mars, however, appears to be relatively desolate and inhospitable, so that a Martian race would be more occupied with survival than we are on earth..  Intelligent beings, if they do exist there, may have protected themselves by scientific control of physical conditions. This might be done, scientists speculate, by the construction of homes and cities underground where the atmospheric pressure would be greater and thus temperatures reduced. The other possibilities exist, of course, that evolution may have developed a being who can withstand the rigors of the Martian climate, or that the race, if it ever did exist, has perished.’" 


            Riordan grunted. "In other words, they're guessing just like we are."

            "It's all anybody can do. But you can figure the odds. Venus seems the next best bet—it might even be on top. In size it's almost a twin of the earth. It's always covered with clouds, so astronomers can't see the surface. But they've figured the cloud temperature at 140, in daytime, so it must get pretty hot on the ground."

            Then I read the Air Force comment:

            "The possibility of intelligent life also existing on the planet Venus is not considered completely unreasonable by astronomers. The atmosphere of Venus apparently consists mostly of carbon dioxide with deep clouds of formaldehyde droplets, and there seems to be little or no water. Yet scientists concede that living organisms might develop in chemical environments which are strange to us. Venus, however, has two handicaps. Her mass and gravity are nearly as large as earth (Mars is smaller) and her cloudy atmosphere would discourage astronomy, hence space travel.'"

            Riordan brushed this last aside.

            "If we can escape the earth's gravity, they could do it there, too. And they might use radio astronomy instead of telescopes. But what in hell would a man—well, call it a man—what would he look like, growing up in that atmosphere?"

            "Probably a lot different from us. They'd almost have to be."

            "You know that Sutton monster story?" said Riordan. "When I first heard of it—well, let that wait. What about the other planets?"

            "Jupiter's not a likely prospect," I said, looking at the file. "Its temperature is around minus 220. Also, the planet's a lot larger than the earth, so its gravity pull is over two and a half times stronger. If you were on Jupiter, you'd weigh close to 600 pounds. You'd have a hard time lifting your feet. And a space ship would have to get up terrific  


speed to escape that gravity pull, though I suppose it's possible."

            "There's one point there," Riordan cut in. "Anybody from Jupiter would be used to heavy gs. We can take up to 50 gs for a second or so. Maybe they could take 100 over a longer time, enough to stand those turns and climbs the discs make."

            "Could be," I said. 'But they’d have trouble if they landed on the earth. It'd be like a human on the moon— they'd have to be weighted down to walk normally. And that holds for Uranus, Neptune, and Saturn, too. From their size, they all must have strong gravity. But they're too cold for our kind of life—somewhere between minus 300 and 400."

            Riordan started to thumb through the Pluto and Mercury folders.

            "I can save you time," I said. "Pluto's nearer our size, but astronomers don't know much about it. It's so far from the sun it's always in darkness, and it's probably near absolute zero in temperature. Mercury is just the opposite. It's so near the sun that one side roasts. The other's always turned away, so it must be freezing."

            "Don't some of those planets have moons?" asked Riordan, as I lit a cigarette. I flicked out my match and nodded.

            "Yes, several of them. Jupiter's got two, Saturn nine, Uranus four—or maybe it's five—and Neptune and Mars have a couple apiece. But some of them are pretty small. Even the bigger ones probably wouldn't be any better than their planets—that is, to live on. That doesn't mean they—the planets, I mean—couldn't have intelligent life on them."

            "You know any scientific background on that? Not this science-fiction stuff, but the big-dome guys."

            There've been several books. I've got a couple—" I brought over my copy of Life on Other Worlds, by Dr. 


H. Spencer Jones, England's Astronomer Royal, and read a marked paragraph.

            “‘It is conceivable that we could have beings, the cells of whose bodies contained silicon instead of the carbon which is an essential constituent of our cells, and of all other living cells on the earth. And that because of this essential difference between the constitution of those cells, and the cells of which animal and plant life on the earth are built up, they might be able to exist at temperatures so high that no terrestrial types of life could survive.'"

            "It sounds crazy," said Riordan, "but when you stop to think, the medicos have frozen some kinds of germs and it didn't kill them. Same for boiling them in water, too, I’ve, heard. So I guess it could be true. But the idea of beings like that with brains like ours—it's hard to swallow."

            I put down the book.

            "There's one consolation. Creatures used to some queer atmosphere couldn't survive here without space suits."

            Riordan gave me a questioning look.

            "Oh, you think that's maybe why they haven't landed? I don't see that that helps much—they could use space suits to attack us or just hit us without landing." He hesitated. "I started to ask about that Sutton monster story. What was ATIC's conclusion?"

"They swear they didn't analyze it, but I'm positive they did check into it." I told him what I knew about the case, and Riordan shook his head dubiously.

            "It sounds as if there was something to it. Not a monster —I still can't see that—but it might have been a robot of some kind, the way they described it. What about that other story—the Florida scoutmaster deal?"

            "So far ATIC hasn't made any report."

            "You think he really saw something alive in that turret, or just imagined it?"

            "I don't know. If Ed Ruppelt's report was on the level, ATIC didn't seem to take much stock in it."

            "I don't either," Riordan said bluntly. Then he added  


with a wry face, "Maybe it's because I don't want to admit some freak from space could be smarter than I am."

            "Sure, I feel the same way. Just the same, it's possible. And remember this; we'd look as queer to them as they would to us. But don't let the monster idea worry you. Whoever's back of the saucers may be a lot like us—maybe even identical."

            Riordan looked startled.

            "How do you figure that?"

            "Well, astronomers say there are millions of other suns. Some top men, like von Weizacker, think it's likely many of them have solar-system planets. Take our own system. Out of nine planets, one is inhabited—the earth. That's 11 per cent. Cut it down to one hundredth of a per cent, out in space, and there'd still be a lot of inhabited planets in the universe."

            "That doesn't mean any of them would be like the earth."

            "Why not? Astronomers say they're all made up of the same elements, maybe in different proportions. By the law of averages, some are bound to be like the earth, with the same atmosphere. Evolution would produce the same land of planets, animals, and people—or approximately the same. Maybe the only difference between us and the saucer people is that they're farther advanced, because their civilization began sooner."

            "I hope you're right," Riordan said soberly. "At least we might be able to reason with our own kind. But wait a minute—think of the distances."

            "Their planet doesn't have to be so far away." I told him about the nearest star system.

            Riordan looked at me incredulously.

            "But, holy smoke, the nearest one's over four light-years from us. You don't really believe anybody'd make a space trip that long?"

            "Yes, if their life span was longer than ours. Some race on another planet may have wiped out all diseases—they  


may live several hundred years. Our own doctors are predicting that we'll do it some day, and we've almost doubled our life span in the last two centuries."

            Riordan knocked the ashes from his pipe. I could see him turning the idea over as he opened his tobacco pouch.

            "That could be the answer," he said. "If they lived, say, 500 years, a trip of several years wouldn't seem so tough."

            "It doesn't have to be the answer. There's another explanation."

            "What's that?"

            "Hang onto your hat," I said. Then I told him about the time dilatation theory.

            "Brother!" said Riordan. "Now we've really gone off the deep end."

            "OK, it sounds screwy. I'll admit I don't understand it. But other big scientists beside Einstein accept it. If you want to check the figures, I've got an article here by a British astrophysicist—"

            "I'll take your word for it." Riordan swung around and stared out into the night. "I wish I hadn't heard all this stuff. Those Intelligence reports prove the things are interplanetary, but they don't give any idea why we're being spied on. I was better off when I thought the saucers were bunk, back in '47."

            "That's what some Air Force officers think—that people are better off not knowing, at least until they find out the motive."

            Riordan jerked around in his chair.

            "But Intelligence must have a damned good idea what's back of all this."

            "They say not. That's why I've got all these cases out here. I've already analyzed them for other angles, but I wasn't looking for motives. So I'm going to recheck—"

            "Let me help you," Riordan said quickly. "I've got the next two days free."

            "We can probably do it in one. It'll be a big help—"

            "Never mind the thanks," said Riordan. "To be brutally 


frank, this is for me and mine. I want to know what this thing's going to mean to us, while there's still time to do something about it."

            After Riordan left, I thought over his last remark. Probably millions of Americans would feel the same way. There'd be some, of course, who'd rather not know, if the answer proved to be bad.

            Next morning, before Riordan arrived, I got out my sighting map and the analysis of saucer types. In the type breakdown all the sightings had been divided into day and night reports, then subdivided according to shape, size, color, speed, and maneuvers, with radar reports serving as a double check on visual estimates of performance.

            It was a long analysis, and to save time for the motive check-up I underlined the main points for Riordan to look over:

            Daytime sightings:

            Type 1. Mother ships, large rocket or "cigar-shaped" machines usually reported at very high altitudes. Sizes estimated by trained observers, from 600 feet to more than 1,000 feet in length; some indications they may be much larger. Color, silvery. Speed recorded by radar, over 9,000 m.p.h., with visual estimates of more than 20,000. No violent maneuvers reported.

            Type 2. Disc-shaped machines of at least three sizes.

A.        Large discs, 100 feet or more in diameter.

B.         Medium-sized discs, with reports averaging about 50 feet in diameter.

C.         Small discs, estimated from eight inches in diameter up to several feet.

            Color of all discs, metallic silver except when showing the effects of overheating. Radar-clocked speeds, over 7,000 m.p.h., with visual estimates of more than 11,000. Maneuvers: Abrupt turns, climbs, and reversals, with very swift acceleration.

            Type 3. Rocket or "cigar-shaped" machines, much smaller than mother ships, reported at fairly low altitudes.


            Sizes estimated from 100 to 200 feet in length. Described as having a fiery exhaust, especially when accelerating. Color, metallic silver. Recorded speed, about 900 m.p.h.; visual estimates, over 1,500. Maneuvers: Less violent turns and climbs than the discs, and no reported reversals.

            Night sightings:

Type 1. No positive visual reports, but accurate radar tracking of mother ships.

Type 2. Discs of various sizes, with estimates less accurate because of darkness and the blinding effect of the discs' glow when seen at fairly close range. Colors, from pink to white-hot heat, sometimes combined with corona effect; also, corona effects predominating, at high altitudes, apparently when discs were not overheating.

Type 3. Rocket-shaped machines, similar to the day­time Type 3, with the same fiery exhaust, speeds, and maneuvers.

Type 4. A machine with rotating red-green-white lights and fixed white beams. May be a rotating disc type. Recorded speed, well over 1,000 m.p.h. Speeds estimated by competent pilots, more than 1,500.

Type 5. Bright green "fireballs," reported mainly over New Mexico. Shape and size unknown. Described as moving silently, at meteor speed, but—unlike meteors—on a straight course. Sometimes reported as exploding silently, over uninhabited areas of the Southwest.

            For radar confirmation ATIC had given me their official analysis:

            "In 35% of all radar tracking of UFO's, radar observations were confirmed visually as maneuvering objects or lights. Night radar trackings outnumbered day cases, 65% as against 35%. The analysis shows UFO speed from zero (hovering) up to fantastic speeds. In 60% of the cases, only one UFO was tracked; in 40%, there were several objects, sometimes sizable formations or groups. About 80% of the tracking was done by radar men at ground bases,


or aboard ship. The remaining 20% was done by aircraft crews or pilots in flight."

            When Riordan arrived, I was working on the map, marking points where saucers had recently been seen. He helped me finish, then looked over my type breakdown.

            "What's the highest speed ever reported?" he asked.

            "About 42,000 miles an hour," I said. "But it didn't have any radar confirmation."

            "Must have been some wild guess," Riordan said skeptically.

            "No, two CAA control tower men at Terre Haute made the estimate. They saw this saucer go streaking over the airport and they figured the arc it traveled in a given time. The 42,000 figure was what they worked out if the saucer was over 3,000 feet high—and they were sure it was. They got confirmation on the sighting. A private pilot and his wife saw the same thing when it went over the atomic energy plant at Newport, Indiana. Even if the CAA guys were way off, it's obvious the saucer was one of the fastest ever sighted. My hunch is that it was a lot higher than 3,000—probably a mother ship that came down lower than usual."

            "This Type 3—the smaller cigar-shaped saucer—have you got many confirmed reports on that?"

            "Well, there was the Eastern Air Lines case, near Montgomery, and the Indianapolis rocket ship last July. Another one was seen at Watsonville, California, by the town police and two deputy sheriffs. They said it was cigar-shaped, flying low and leaving an exhaust trail. Later some people saw it at a couple of other California towns. There have been several foreign cases, and the 1949 Project Sign summaries mentioned quite a few."

            Riordan nodded.

            "I guess it's definitely a separate type, then." He read over the night sighting list. "Those green fireballs—I haven't heard much about them."

            "The stories on that broke while you were in Korea. It


has puzzled the astronomers—at least some have publicly admitted it's got them stumped. One of them is Dr. Peter Millman; he's Canada's top astrophysicist. Another is Dr. Lincoln La Paz, down at the New Mexico Institute of Meteorics. La Paz has been studying the green fireball deal, and he says they're not any kind of meteor he ever heard of."

            "Why not?" said Riordan.

            "For one thing, they don't make a sound. Also, they go straight, and meteors take a curved course. And La Paz says they wouldn't come that often if they were meteors— for a while, they were coming thick and fast. It's been going on since December, 1948." '

            "Just in New Mexico?"

            "No, they've been sighted in the East, and down in the Caribbean. But the Southwest seems to get most of them. One funny thing, no fragments have ever been found. Ordinary meteors usually leave some trace when they explode, if you look long enough. But the Air Force search parties haven't found a thing."

            Riordan's black eyes flicked over at me.

            "Then the Air Force takes it seriously?"

            "Enough to set up a special project—they called it 'Project Twinkle.'" I told him about the three theodolite stations established at Vaughn, New Mexico, to get accurate triangulations on the green fireballs. Oddly enough, the mysterious objects were never seen by the men at Vaughn, though they were constantly reported over the rest of the Southwest. But when the project was moved to Holloman Air Force Base, New Mexico, the investigators had better luck. Several of the bright green balls were tracked up to the moment of explosion, at a speed of about 40,000 miles an hour. But searches over a wide area, under the explosion points, all proved in vain.

            "What did they finally decide?" Riordan asked me.

            "I don't know. The report's still secret."

            "That doesn't look very good," Riordan said slowly. 


"They must have been pretty worried in the first place, to set up a special project. And then to sit on the answer—"

            "There's something odd about it, all right. Project Sign investigated the green fireballs, too, but they omitted most of the cases in the 1949 summaries; I just happened to spot a reference to them in another section. And the red spray cases don't sound good, either."

            "The red spray cases? That's a new one to me."

            "They happened back in '48. The things came down to 200 feet and exploded—" I started to get out the Project Sign summaries, then changed my mind. "Let's wait on that  until we finish checking the map. Seeing those cases now might give you a wrong slant on the whole picture."

            Riordan eyed me narrowly.

            "I don't like the way you said that. If you mean what I think, it's bad news."