In the Davis Mountains south of Pecos and Balmorhea, there is a cluster of white domes—the McDonald Observatory. A girl named Lily Dominguez worked there as a bookkeeper. Juan had known her since junior high school, and when he felt that he had a prospect of a career before him, he proposed marriage to her. She accepted, and Father Girán married them, but Apolonio did not fire his revolver at the wedding because the practice of vivas had run out of style with the modern times. Lily quit her work at the observatory in order to marry Juan. They moved to the city of Pecos, where Juan got a job in Angel’s Barber Shop, on the edge of the barrio. In the barrio they called Angel “El Maestro.” He came from Mexico, where the barbers have extremely refined manners. Angel could do anything—flats, ducktails, he could wax a mustache into points, he could make all the shapes and styles of sideburns, from Rudolph Valentino to Prince Albert, and he could shave heads. He had a row of showers in the back of his shop, for the use of which he charged twenty-five cents, and he bought a new car every year.
In the end, Pecos did not suit either Lily or Juan. Juan was not buying a new car every year. “I was very ambitious,” Juan recalled. “I said to myself, ‘How can a man get rich cutting hair?’ ” Meanwhile the observatory missed Lily. They urged her to return to the mountain and to bring her husband. They offered to train him as a night assistant. “I was pretty scared,” Juan said. “What did I know about telescopes?” He and Lily moved to the McDonald Observatory, where the astronomers appointed him the night assistant on the eighty-two-inch McDonald reflector, then the largest telescope on the mountain, while Lily worked as the observatory’s cook, housekeeper, and bookkeeper. The large McDonald reflector was a tricky telescope, and to operate it one needed the touch of a maestro. That was not all. The astronomers wore electrically heated flight suits (similar to the ones on Palomar) that were supplied with electricity by a wire that ran from a wall socket into the suit’s rump. When the astronomers became overexcited, they would run around the dome shouting, unplugging themselves, dragging their wires all over the place. Juan learned that a part of a night assistant’s job is to prevent astronomers from electrocuting themselves.
The same year he married Juan and Lily, Father Girán went to live in a retirement home for priests in New Mexico. Juan and Lily went up there to visit him. “He was very old then,” Juan recalled, “but still very, very strong.”
He was also delighted to hear that Juan had gone into astronomy. “My mind,” Father Girán said, “doesn’t remember things anymore. I would like to discuss astronomy with you, Juanito, but I find I have forgotten it. Yet I remember those nights … those nights when I told you about the stars. All those nights … You sit there with those astronomers. You listen to what they say. Now, you know, astronomers never get rich. But if you stay with them, you will learn, Juanito. Because astronomers are the chosen. They are the chosen.” This was Father Girán’s last conversation with Juan; he died shortly afterward.
After working at the McDonald Observatory for eight years, Juan and Lily turned their thoughts to southern California. In 1964, they moved to San Diego, where Juan found work in a physics laboratory, measuring the tracks of subatomic particles in a bubble chamber. By this time he had finished a correspondence course and had received a high-school diploma, and he had also begun to study computers. (“I am not totally ignorant of ‘and/or’ gates.”) After several years at the physics laboratory he realized that he was about to be replaced by a computer, and so he decided to look for a job that would never be taken away by a machine. Night assistantship came appropriately to mind. One day he drove up Palomar Mountain and asked the mountain superintendent for a job. He reported to work on September 9, 1969, cutting underbrush and dusting the Hale Telescope with a mop. That was when he discovered his respect for heights, because he had to walk out onto the I-beams of the main tube, several stories above the mirror, pushing a dust mop in front of him. The mirror was covered, but if he had fallen on it, he still might have broken it, and he did not want to break that mirror, because while man is dispensable, telescopes are not.
By Christmas he had been promoted to relief night assistant. He learned how to slew the Hale Telescope—move it fast across the sky. Gary Tuton, who was then the senior night assistant, trained Juan. Juan was terrified that he might crash the Hale during a high-speed slew. What would it be like, he asked himself, to go down in history as the guy who had wrecked the largest telescope on earth? He reminded himself that he had never cut a customer.
The Hale had tendencies. It tended to pop its clutches. During heavy slews, one could smell burning rubber. The dome tended to lose track of where the telescope was pointing. Juan’s notebooks tended to multiply. During cold weather, the film of oil under the horseshoe bearing might thicken, and the Hale would stop tracking the stars. That would trip an alarm buzzer, and the astronomer would open his mouth and prepare to scream. Juan would dash to a ladder resting against the telescope’s north pier. He would climb three stories up the ladder until he came to a set of screws. He would take a little screwdriver out of his pocket and give one particular screw a quarter of a turn. One-point-one million pounds of telescope would resume tracking the stars, while the buzzer would shut off and the astronomer would return to normal.
Occasionally the telescope refused to slew. Juan would dive into the elevator and descend one level, then hurry along a walkway until he came to a bank of circuit breakers. Using both hands, he would hit every breaker switch as fast as he could, working his way down a wall of switches. If the Big Eye still would not move, he wrote down at least a dozen other things to remember. These included:
• Think of the oil pads.
• Check the clutch lights.
• Check the central hoist—if it is slightly raised, telescope will not slew.
• If the dome starts going back and forth, or “hunting,” then the brake is too loose. A touchy little beast. Try just tapping the brake with a screwdriver first.
• If the mirror cover will not open and telescope will not slew, check the small DC motor next to the huge MG SET. Tap it if it won’t start.
Sometimes the dome would get confused and start turning around and around, and the whole building would shake, and nothing could stop it. “Juan! This is crazy!” the astronomer would say.
“It’s the phantom,” Juan would say. Juan would dash into a room at the south end of the telescope. The phantom was in there. The phantom was a mechanical computer built by Bruce Rule. It caused the dome to follow—to phantom—the movements of the telescope. Juan would wiggle and snap moving parts in the computer. He would inspect and remove two vacuum tubes and wipe the tubes with a rag. Usually the dome would stop spinning.
The engineers seemed to be superstitious about oils. Cans and bottles had piled up on shelves next to Juan’s locker. Some of the oils Juan learned the use of, and some he did not. There was Lubriguard Anti-Seize, Mobil Extreme Pressure oil, Graham transmission oil, Way Lube chain oil, Marvel Mystery oil, Gargoyle Grease. Bob Thicksten was trying to switch to a few simple oils, but Juan wondered if things like Gargoyle Grease and Marvel Mystery oil were not still ending up inside the Hale Telescope, either because those oils worked or because the engineers had bought them on special somewhere. Mobil had recently quit making Flying Horse telescope oil, which had caused observatories all over the United States to go into a panic. Thicksten had snapped up ten drums of Flying Horse, which he stored as if they were cases of ’59 Margaux, in dark recesses of the dome. Thicksten believed that the use of Flying Horse oil was another of those black arts: perhaps unnecessary but foolproof.
After a nine-year apprenticeship Juan became the senior night assistant. Soon after his promotion the observatory installed computers to monitor and control some of the motions of the Hale Telescope. These digital systems had partly replaced Bruce Rule’s clockwork computers. Juan now had a computer terminal at his control panel, through which he orchestrated many of the motions of the Hale. But the observatory had deci
ded that no computer could ever be allowed to slew the Big Eye, because a computer would sooner or later crash the telescope during a high-speed slew. Man was not entirely dispensable. Especially this man, who could shave a wino with a straight razor and do a perfect flat. He had spent more time looking at the Hale’s video screens than anybody, including Maarten Schmidt, which had forever changed his feelings about the earth’s place in the creation. “Now when I look into the blue sky,” he said, “I wonder where it all ends.”
The Trojan planets were slow-moving, predictable bodies. Once you had sighted one, you could usually find it later. Carolyn Shoemaker felt no compulsion to quickly search the films that resulted from her and Gene’s Trojan runs on Palomar Mountain. She did go over the films lightly, looking for fast-moving objects, and she found an asteroid called 1985 WA. 1985 WA could hit Jupiter, which was a pleasant surprise—it was a Jupiter-crosser. In any case, after New Year’s of 1986, she and Gene returned to Palomar Mountain for a week, to survey the sky for earth-approaching asteroids, while the Trojan films remained in their glassine envelopes in Flagstaff, Arizona, unsearched for Trojan planets.
On Palomar Mountain, Carolyn found the first new comet of 1986. It turned out to be a regular visitor to the inner solar system—Periodic Comet Shoemaker 3. Then she found the second comet of 1986. This one, designated 1986b, was a long-period comet. It took a hairpin turn around the sun and left the inner solar system; it will be back in the spring of A.D. 2509. “I am now tied with Caroline Herschel,” Carolyn said. “Of course, I am going to beat her.” But the Trojan films remained in their envelopes, unsearched for Trojan planets. “As usual,” she said, “I am sinking under a pile of films.”
During March of that year, Periodic Comet Halley made an appearance in the sky. Maarten Schmidt’s quasar team happened to be scanning on Palomar Mountain at the same time, and they were anxious to see Halley’s comet, since none of them had seen it before. Maarten Schmidt brought his binoculars to the mountain. At four-thirty one morning, he and Gunn climbed to the catwalk. A cloudless wind came out of the west, hissing around the dome and snapping the tops of the cedars, warning of a storm coming from the Pacific Ocean.
Maarten held up his binoculars. “This is marvelous,” he said.
“I had expected worse,” said Jim.
“The comet looks fairly bright,” Maarten said.
“This is quite spectacular.”
Halley’s comet had a white nucleus. It looked like a fuzzy star. The tail was cloudy and faint. The comet resembled a dust ball, a piece of celestial trash.
Maarten said, “Gad, these binoculars are terrible. I paid only fifty dollars for them. My apologies, James.” He handed them to Gunn.
Gunn plugged the terrible binoculars into his eyes and turned the focus knob. His hair strayed in various directions.
In a philosophical sort of way, Maarten continued. “I think we are overdue, James, for a really bright comet.”
“I absolutely agree.”
“Like the great comet of 1843,” Maarten said. “With a tail that goes halfway across the sky. It would be interesting to see what effect that would have on the popular mind, as it were. Whether we would hear talk of the end of the world and so forth.” (Schmidt had studied comets with Jan Oort at the University of Leiden, where he had become interested in the effect of comets on the mind. He once remarked to me—we were talking about the Shoemakers and their comets—“I believe it was a comet in the seventeenth century that touched off a riot of shoemakers in Germany. There must have been more shoemakers then. And I bet you they were well organized.”)
“The tail is developing nicely,” Jim said. Then the binoculars strayed away from Halley’s comet. He pivoted slowly on his feet, moving from point to point along the Milky Way. “The Trifid nebula is up,” he said. “And there’s M22—that’s a fantastic globular cluster. And there’s the Omega nebula.” He handed the binoculars to me. He said, “You can see the Omega. It’s right above the Lagoon nebula. What you can see with a pair of binoculars is actually quite mind-boggling.”
The central bulge of the Milky Way fattened toward San Diego. The galactic core was rising over San Diego. Seen through a pair of binoculars, the central region of the galaxy is speckled with dots of glowing gas and cut with black streamers of entrained dust. Halley’s comet hung immediately below the Milky Way—obviously near the earth. Halley’s comet is a lump of black, dusty ice the size of Manhattan, shaped like a potato—and it travels on a chaotic earth-crossing orbit. It used to live out in the Oort cloud, until it felt the gravity of a passing star and fell toward the sun. Now it steams every time it approaches the sun. Someday it may break up and dissolve into dust, or it may become an extinct comet nucleus. If some kind of dark nodule remains, then one day Halley’s comet may hit the earth as an asteroid, causing mass extinctions, although that is not likely. More likely, Halley’s comet will have a close encounter with Jupiter during the next million years, and Jupiter will fling it off into the stars, to travel forever through the Milky Way.
Just three weeks before that, Carolyn Shoemaker had found an asteroid that she and Gene named Amun. Amun is the kind of earth-crosser that creeps up alongside the earth. Amun is a mile and a half across and is made of metal. “When Amun hits,” Gene said, with a good deal of satisfaction, “it will make a real crater.” Carolyn also spotted an object slanting through the plane of the solar system, moving fast—an object now designated 1986 EC. She measured its motion in two films taken as the moon was beginning to wax, washing out the night sky. Then she lost it. 1986 EC drowned in moonlight and has not been seen since.
“I hate to lose one of those things,” Gene said.
Carolyn was chagrined, if not embarrassed. “I just hope it will be picked up someday,” she said. Meanwhile the Trojan films remained untouched. “I’m not worried about those Trojans,” she said. “Those planets are not going anywhere. They can wait.”
On May 5, 1986, on Palomar Mountain, Carolyn found a strange minor planet in a pair of films that she and Gene had taken a few days before—a slow-moving asteroid, and going the wrong way, against the flow of the Main Belt. Carolyn telephoned Brian Marsden, the director of the Minor Planet Center, and gave him a set of rough coordinates. He gave the asteroid a temporary label: 1986 JK. The Shoemakers took more photographs of 1986 JK on following nights, while continuing to report the object’s changing positions to the Minor Planet Center. Brian Marsden shortly informed the Shoemakers and the rest of the world (via international astronomical telegram): “1986 JK appears to be an Apollo object approaching the earth.” Astronomers rushed for their telescopes. The asteroid’s slow motion was an illusion: the Shoemakers were watching it head straight at the earth. JK reversed its apparent motion, accelerated wildly, and boomed past the earth on June 1, 1986, at a distance of 2.6 million miles, one of the closest asteroidal misses on record. By the standards of normal planetary motions in the solar system, the apparition of 1986 JK was somewhat akin to having the hair on one’s head parted by a bullet. JK was traveling on a long ellipse, like the orbit of a comet. Radio astronomers using an antenna at the Goldstone station of NASA’s Deep-Space Network bounced a radar signal off the asteroid as it went by and received a clear echo, which suggested that JK is a big object. Its orbit takes it out as far as Jupiter. It is an earth-crossing Apollo object, and a Mars-crosser, and a Jupiter-crosser. 1986 JK could hit the earth, Mars, or Jupiter. At intervals of fourteen years, marking time like a metronome, it whips past the earth. Around Independence Day in the year 2000, it will be back in our skies on a close pass.
During the autumn of 1986, one year after the Shoemakers had taken the Trojan photographs, Carolyn decided that she would try to find some Trojan asteroids. She selected thirty-three stereo pairs of films to search. The photographs looked through the plane of the solar system, into the Greek cloud of asteroids that traveled ahead of Jupiter. Accustomed to looking for fast-moving asteroids near the earth, Carolyn had to train herself to
see slow-moving specks hanging in space out near Jupiter. She set up her microscope in a windowless storage room at the back of the library of the United States Geological Survey’s headquarters in Flagstaff, where she could look at the sky all day without interruption. She fastened pairs of negatives into the microscope.
She looked through binocular eyepieces and saw a white sky, as it is called. The photographs were negatives, in which the sky appears white and the stars black. (The human eye can more easily discriminate a black dot against a white background than the other way around.) She moved the films back and forth while stars passed through her field of view; this felt to her like flying through space. Each stereo pair of films contained about ten thousand dots—stars, galaxies, quasars, and asteroids. The stereo pairs had been photographed at time intervals of forty minutes. During forty minutes a Trojan planet would move against the background of fixed stars.
The stereo microscope was a clever tool for finding objects in motion—it made them pop into stereo. Trojan planets hung in the distance, barely in front of the stars. She could see the depth of the Trojan cloud; the Trojans were distant objects, well beyond the Main Belt asteroids that sprinkled the foreground of her films. An asteroid approaching the earth, on the other hand, could seem to hang in front of Main Belt asteroids. These earth-crossers moved aggressively, at odd angles. Traveling at perhaps thirty-four thousand miles per hour, an earth-crosser could go a long distance in forty minutes. “The asteroid is moving so fast,” she said, “that you see a displacement in the image. You can’t fuse it with your eyes—it seems to blur out. It hops.”