First Light: The Search for the Edge of the Universe by Richard Preston
I said, “It sounds like you and Carolyn plan to discover a new asteroid belt.”
“Van Houten discovered it, in a sense—when he came up with that estimate of nine hundred Trojans. I just think it’s a heck of a lot bigger than anyone else does.”
A smell of damp creosote bushes filled the air. It had been raining in the desert. Not a good sign. “Heaven knows what it’s doing on the mountain,” Carolyn said. We climbed into the Fury, slammed the doors, and she floored the accelerator.
Gene began to talk about comets. One of the more intriguing shells of debris, to him, was the solar system’s reservoir of comets. Beyond the outermost known planet, Pluto, there is a spherical shell of comets known as the Oort cloud, named after the Dutch astronomer Jan Oort, who demonstrated its existence. The Oort cloud contains a prodigious number of comets—anywhere from one trillion to one quadrillion comets (nobody can say how many) traveling in circular orbits around the sun, orbits that may average about a light-year from the sun. (If Pluto’s orbit were the size of a dime, then a typical Oort comet would circle about ten yards out.) Comets are lumps of crumbly material, five or ten miles across, containing various kinds of ices, silica dust, and carbonaceous compounds. Comets are primordial pieces of the solar system, trash left over after the planets formed.
From out in the Oort cloud the sun would look like a bright star. Out there a typical comet travels slowly in relation to the sun—about three hundred miles per hour. Out there a comet can feel the gravity of stars other than the sun. The sun, Gene pointed out, was circling around the galaxy in the company of stars all around it (his vision of the galaxy ran parallel to his vision of the solar system: the galaxy was a collection of moving objects). All the stars in the sky were in motion around the galactic center, like traffic on a freeway. If a comet feels a gravitational pull from a passing star, the comet can, in some cases, be slowed down nearly to a halt—to a speed of around five or ten miles per hour in relation to the sun. Then it does what any object would do if suspended motionless over the sun. It falls toward the sun. By the time it reaches the inner solar system, the comet is falling at outrageous velocity. It takes a hairpin turn around the sun and heads back for the Oort cloud. Some comets actually hit the sun. Pondering comets dropping through the solar system, Gene Shoemaker wondered how often comets got trapped in the zone of planets. A comet could loop past Jupiter, for example; be slowed down by Jupiter’s gravity; and wind up in an orbit near the sun. The zone of planets might be filled with invisible comets. The comets were invisible because they no longer sported tails. A comet began to steam as it neared the sun and the ices in it evaporated. The comet threw off dust as well. The result was the well-known display of a tail. If a comet was trapped in an orbit near the sun, then over time the ice in the comet nucleus might steam away.
One school of thought held that the ice in comets finally evaporated, leaving nothing but a whiff of dust behind. Gene disagreed. He suspected that a black nugget might remain—an extinct comet nucleus, maybe a mile across. “As the comet degasses, it grows a crust of dirt on it,” he said, “like melting snow. You get the buildup of a lag deposit on the surface of the nucleus, probably some kind of polymerized hydrocarbon and rocky stuff, sort of like asphalt.” The surface of an aging comet nucleus began to resemble a melting snowbank in the Bronx. The center stayed frozen, while the outer surface of the nucleus grew a skin of crud. As the crud thickened, the nucleus stopped throwing off dust. The tail vanished. Seen through a telescope, the comet now looked like a black asteroid. By definition it was now a minor planet on a chaotic orbit, a loose cannonball, rolling at large through the solar system.
A dead comet might wash up in a number of places. Its most probable fate would be to pass close to Jupiter and be whiplashed out of the solar system. Or perhaps it might get trapped inside the asteroid belt, to mix with the asteroids. Or it might hit Jupiter. Or—just possibly—it might end up colliding with the earth.
At three o’clock in the morning Carolyn swung the Fury into a truck stop in the Mojave Desert. We sat at a counter while a waitress in a checked pantsuit poured out three cups of coffee.
Had there been more comets at times in the past? Gene wondered out loud. Had there been comet showers? he wondered. What could cause a comet shower? He pondered these questions while he swigged coffee.
The waitress stood by the cash register with her arms folded, watching Gene. The coffee shop was otherwise empty.
Carolyn remarked, “Gene’s wheels are always spinning.”
“Yeah,” he said, “and every now and then something kicks out.” What would happen, he asked, if a star as big as the sun brushed near enough to the solar system to drill through the Oort comet cloud? He said, “I’ve calculated that we might have a close encounter with a big star maybe once every hundred million years. If a star the size of the sun went by slowly, it could give the Oort cloud one hell of a kick. That star could bore a hole through the Oort cloud. Comets would diffuse out of the cloud in all directions, which would increase the bombardment rate of the earth. We might be in the tail end of a comet shower right now.”
The waitress came over. “Need ‘nother coffee?”
“Sure,” he said. “A comet coming in from the Oort cloud could do some damage if it hit.”
The waitress filled our cups. She peered at Gene.
“These guys,” he said, “travel at sixty-five kilometers per second, relative to the earth—that’s triple the speed of the average near-earth asteroid.” During a comet shower the earth might experience a series of bad random hits, like a chain of nuclear attacks. One result, in the past, might have been the wave of animal and plant extinctions at the end of the Cretaceous period, sixty-five million years ago, when something like half of the species on earth vanished, including the dinosaurs.
Gene went to the rest room, and the waitress chose that moment to come over with the check. She said quietly to Carolyn, “Have you all seen the Space Center up north of here?”
“You mean Edwards Air Force Base?” Carolyn asked.
“No. You know—where the starships landed.”
“Oh?” Carolyn said.
“Where the aliens left those rock piles. You must’ve heard about that—since your husband is interested in that kind of thing. Those messages to outer space.”
“That sounds interesting,” said Carolyn.
“There’s forces that keep the rocks together. Kids on motorbikes will knock the rocks away, you know? And the rocks will move back during the night. Nobody knows how it happens.”
Carolyn paid the check.
The waitress added, “It might be some kind of magnetic force.”
“We should go and have a look,” Carolyn said.
“Don’t miss it. Spacemen landed there. Have a nice night.”
The Pacific Ocean sent a series of cloud fronts over Palomar Mountain, leaving the astronomers there feeling swindled. We stayed in a cottage on the hillside below the dome of the eighteen-inch telescope, staring out the windows over long breakfasts in the early afternoon. After breakfast we would hike or drive up to the dome, where Gene and Carolyn would tackle such work as they could find, while waiting for the weather to clear. The dome of the Little Eye, as astronomers sometimes called the eighteen-inch Schmidt telescope, was shaped like a bullet. The dome was eighteen feet across, offering more than a slight resemblance to a space capsule. It had two floors. On the lower floor were a tiny office, a darkroom, a supply closet, and a bathroom. On the upper floor stood the telescope. The entire dome would have almost fit inside the barrel of the Hale Telescope.
Gene worked in the darkroom. He mixed up tanks of darkroom chemicals. He unraveled a spool of Kodak IIa-D astronomical film, as big as a roll of paper towels, and chopped the film into six-inch disks, using a machine he called the Cookie Cutter. A boisterous racket came out of the darkroom. Whomp. Then a muffled “Damn.” Whomp. The Shoemakers called these disks of film cookies. Gene filled three ammunition boxes wit
Carolyn set up her microscope in the dome’s office and passed the time searching old films for asteroids. She always had a backlog of films. Her children marveled at her growing passion for minor planets, although perhaps they missed her a bit, because she spent so much time on Palomar Mountain. She listened to the radio while she worked, to a station that claimed it brought you absolutely the easiest listening in southern California. Every now and then she pulled apart the slats of a venetian blind to examine cloud streets and mares’ tails sliding over the mountain. Life on Palomar goes catatonic under clouds. Down at the Monastery, astronomers sat around watching television, hoping for news of a break in the weather.
At the Little Eye, Gene spread out a sheaf of papers and wrote numbers in columns, planning the star fields they would photograph during that run; a geologist plotting a raid on heaven. This weather was beginning to get to him. He began to wonder if the Trojan planets would escape. He paced the office, looking over Carolyn’s shoulder. One afternoon he suddenly vanished into the supply closet. Then his voice boomed: “Where did all these ants come from?” Tiny black ants plagued the eighteen-inch dome, and they had infested the supply closet. “Something really ought to be done about these ants,” he said. But he had no idea what. He emerged with a jar of peanut butter and a spoon. He said to Carolyn, “Is this our peanut butter or has it been here awhile?”
“It’s been here awhile.”
“Want some?”
“No thanks, she said.”
He pulled his half-glasses down his nose and inspected the peanut butter for ants. “Hm.” He spooned a gob into his mouth. He swallowed it tentatively. Not immediately toxic, anyway.
“I’ve got something here that looks like a comet,” she said.
“Oh, yeah?”
“A little fuzzy comet.” She studied a loose-leaf binder containing recent notices of comets.
He sat down at the microscope. He couldn’t find the comet. “Sometimes,” he said, “I think I’m losing my—”
“Marbles?” she said, teasing him.
“Oh, yeah. It doesn’t have a well-defined nucleus.” They concluded it was only a galaxy.
Gene thought that he would call Bob Thicksten, the observatory superintendent. “Hi, Bob. Just wanted to see what our status is on the clocks.… Still slipping some? Uh-huh …”
“Rats,” Carolyn said.
“We’ll follow it carefully. What’s the weather going to do? Grim? Ha, ha, well, the sky looks better than it has all day.”
Gene’s hopes for better weather proved to be unsupported by reason. A loud noise rattled on the metal dome. “What is that?” he cried, opening the door. A flash of lightning spilled into the office, followed by a rumble. “Aw, for crying out loud,” he said. The ground was covered with hail.
This kind of thing went on for three days.
One afternoon Don Schneider showed up at the Monastery for breakfast. He poured some Rice Krispies into a bowl, juggled a hot Danish pastry out of the microwave, and said, “It’s going to clear.”
That jerked a few heads at the table.
“Have you heard a weather report, Don?”
“No, but Maarten Schmidt is arriving tonight.”
“Oh, yeah. Maarten is supposed to have luck with weather.”
“It isn’t luck.”
“What—does Maarten have a hot line to God?”
“No,” Don said. “God has a hot line to Maarten Schmidt.”
That evening, something in the gestures of the clouds tempted the Shoemakers to walk to the Hale dome, to get up on the catwalk for a view. They followed a road along the ridge, past scrub oaks and chokecherry bushes. Small flocks of birds flew in the wind. The air smelled of dead leaves and carried an edge of cold. A flicker of white and blue burst out of the underbrush, and a blue jay took off with a chokecherry in its beak. The Shoemakers circled the catwalk of the Hale dome, eyeing the clouds.
“Heaven knows what it will do,” Carolyn said.
“A clear night’s not impossible,” Gene said hopefully.
As they so often did, they spent a moment admiring the Hale Telescope from a walkway inside the dome. “Anybody who isn’t awed by that thing doesn’t have a soul,” Gene remarked. The Hale had something in common with the Hoover Dam, perhaps the naïveté of a world that still believed in its machines. The Hale Telescope embodied some of the longings of the twentieth century, and some of the terror. Gunn and Schneider were working in the cage at the base of the telescope, preparing for a quasar search. Something glittered in Gunn’s hands: the pyramid of mirrored quartz that broke starlight into four beams.
The Shoemakers cooked some quick hamburgers in the cottage where we were staying, in case the weather cleared. We ate them quickly, watching the clouds through the window. At dusk, while we were sitting around drinking coffee, we noticed a tall figure walk by on the road, his hands in the pockets of his parka and his head down, lost in thought. Maarten Schmidt had arrived. Ten minutes later the clouds broke and vanished.
Gene and Carolyn stuffed the coffeepot into a paper bag, along with a pack of Oreos, and carried the bag out to the Fury. They drove up to the little dome and parked. While Gene worked in the office, Carolyn climbed to the upper floor of the dome and pulled a plastic sheet off the telescope (the dome leaked). She hit a button. With a screech bad enough to spall one’s teeth, two curved doors on the dome pulled open. Hitting another button, she rotated the dome to the north, toward Cygnus, the Swan, a constellation that straddles the Milky Way. Twilight had eased off, and the black rift in Cygnus—a lane of dust in the Milky Way—was beginning to stand out. Hauling on a circle of hand holes at the telescope’s base, she pointed it at the brightest star in Cygnus—Deneb—and looked at it through a guide telescope mounted on the barrel of the Schmidt. She fiddled with the Schmidt for a while, calibrating it. Not much bigger than a refrigerator, the telescope was coated with Dutch Boy battleship-gray paint. Rivets and dents on its tube suggested the hull of a submarine that had had some close calls with depth charges. Styled and built during the Depression, the Little Eye looked a bit like an aerodynamic pear, a design that its builders had evidently hoped would carry it smoothly through the winds of the future.
Gene came up the stairs. He put a pile of papers on a control desk next to the telescope. “The weight!” he said. The Schmidt had been slopping all over the sky (due to loose gears), and Jim Gunn had joked about hanging some lead on it to tighten down the gears. Gene had found a lead weight from a freight scale. He now lifted it from a shelf and hung it from the telescope on a loop of clear packing tape—Palomar Glue. He patted the Schmidt and said, “This oughta keep the gears tight.” He grabbed the telescope, tipped it over until it pointed sideways, and snapped open two doors on its side. Carolyn handed him a film holder, which contained a circular piece of black-and-white photographic film—a cookie. He stuffed the film holder through the doors of the telescope, locked it in place, and snapped the doors shut. “Ready,” he said.
Carolyn went to the control desk and read off the coordinates of the first exposure. “Right ascension twenty-two, thirty-two point zero.”
Pulling by a hand hole in the base of the Little Eye, he slewed it across the sky, while dials on the wall told where the telescope pointed.
She said, “Declination plus fifteen, forty-seven.” Her words smoked in the cold.
He slewed again. The telescope arrived at the edge of the Trojan cloud, now rising over the ridge to the east.
He sat on a stool, flicked off the lights in the dome. He peered into the eyepiece of the guide scope. He saw a set of crosshairs and a bright star—his guide star. He said, “What’s the magnitude of this star, dear?”
“Six point four,” she said.
The guide
“Five,” she said, “four, three, two, one, open.”
He reached up, pulled a lever, and two shutter leaves on the skyward end of the telescope opened like a pair of unclasping hands.
“Liftoff!” she said.
The telescope’s automatic tracking drive would keep the crosshairs on the guide star while the sky moved and the telescope gathered light. Sometimes the guide star would go oop, slip off the crosshairs. Heaven doesn’t jerk; telescopes do. He would work buttons on the paddle frantically to get the crosshairs back on the star before the photograph smeared.
The guide star suddenly kicked away from the crosshairs, and he said, “Bad hiccups!”
“We’re looking east, Gene.”
“It’s horsing around. It’s going all over the lot.”
“That’s a disaster, Gene.”
“Ah, damn!” he said, and there was a sound like zeee, zeee while he punched buttons on the paddle. “This gear is worn,” he said. “The telescope is oscillating back and forth.” A flash of blue sparks danced around the telescope’s mounting.
Carolyn said, “You might try putting the weight on the other side.”
He switched on the lights. He put the weight on the other side of the telescope. Carolyn tugged the telescope to the coordinates of the next photograph while he studied a dial on the wall. “The clock could be slipping,” he said. Bob Thicksten had warned him about that. “This is just incredible,” he said.