SPECIAL REPORT: Kohoutek: Comet of the Century

Some day there will arise a man who will demonstrate in what regions of the heavens the comets take their way; why they journey so far apart from the other plan ets; what their size, their nature.

— Seneca

That prophecy, written by the Roman philosopher and statesman nearly 2,000 years ago, may soon be fulfilled. Growing brighter every morning in the predawn sky, one of the largest comets ever seen by man, its elongating tail stretching across millions of miles of space, is streaking toward a Christmas rendezvous with the sun. Later this month and through most of January, the giant comet should provide an extraordinary celestial spectacle, and may well help answer the questions that Seneca raised so long ago.

The fiery visitor is called Kohoutek (after its discoverer, Czech Astronomer Luboš Kohoutek— pronounced Loo-bosh Ko-hoe-tek); it promises to rival and perhaps surpass in brightness Halley’s comet, which last appeared in 1910 and will not be seen again until 1986. By the time Kohoutek emerges from its passage behind the sun early in January, its tail should be full grown, a glittering streamer extending across as much as a sixth of the evening sky. There is some chance that Kohoutek will not live up to all its billing — comets are notoriously unpredictable. Some split into several parts as they approach the sun; others disintegrate completely or simply fail to achieve their predicted brilliance. But Harvard Astronomer Fred Whipple, the dean of U.S. comet watchers, has high hopes for Kohoutek’s performance. It “may well be the comet of the century,” he says.

Until recently, professional astronomers, more concerned with planets, distant galaxies, quasars and pulsars, left the observing of comets largely to amateurs. Comets were “bagfuls of nothing,” sniffed Percival Lowell, the turn-of-the-century astronomer who made a career of observing Mars. Since that putdown, scientists have learned to take comets more seriously—as primordial chunks of matter left over from the birth of the solar system 4.6 billion years ago. Thus Kohoutek, which was spotted first at the Hamburg Observatory last March, offers a splendid opportunity for observers to learn more about the drama of creation. Indeed, because the comet was discovered so long before its close approach to the sun, there has been time for elaborate preparation. Kohoutek may well be the most intensely scrutinized celestial object in the history of astronomy; it will be tracked and studied by thousands of scientists and an incredible array of instruments ranging from the 200-in. telescope on Mount Palomar to the sophisticated devices aboard Skylab and other spacecraft.

Comet Flight. Excitement about the comet is not confined to scientists. Planetariums round the world are drawing overflow crowds for Kohoutek shows. Telescopes and binoculars are being sold at an exceptionally brisk pace; Edmund Scientific Co., of Barrington, N.J., reports a 200% gain this year in its sale of telescopes; Los Angeles’ Marschutz Optical Co. is completely sold out. This week the Queen Elizabeth 2 sailed from New York, booked to the gunwales with 1,693 passengers on a three-day comet cruise. Before dawn every morning, passengers were invited to the decks for telescope viewing and comet lectures. In January, when the comet will be visible in the evening sky, New York’s Hayden Planetarium is planning an even more elaborate happening: a six-day “Flight of the Comet” aboard a chartered Boeing 747. The tour will feature stopovers at observatories in California and Arizona. There, the participants will be treated to candlelight dinners and lectures while Kohoutek glimmers in the sky. Cost: $1,750 apiece.

The reaction to Kohoutek is also taking more metaphysical forms. A militant Jesus cult called the Children of God, which claims a worldwide membership, is convinced that the comet is an omen of disaster and is directly predicting doomsday (“Forty days,” warns the group’s leader “Moses David” Berg, and “Nineveh shall be destroyed!”). A different alarm is sounded by the Italian parapsychologist Astaroth, 52 (real name: Claudio Giannantonio), who counsels members of the Rome political and movie set. Astaroth explains that comets disrupt the “psychomagnet-ic equilibrium” of the planetary system. He adds: “Human beings will be drawn to commit acts of violence—not only singly but collectively.” In McFarland, Wis., the self-proclaimed head of the Church of the Odd Infinitum, Edward Ben Elson, is selling tickets at $10 each for his intergalactic spaceship (“No warranties expressed or implied”). He says it will take off Dec. 24 before the comet’s gases can ignite the earth’s oil supply and bring death to most of mankind. UFO Cataloguer and Astronomer J. Allen Hynek, who was born under Halley’s comet in 1910, is taking a more realistic view; he is bracing himself for a flood of calls at his Northwestern University UFO center from people worried about the fiery space spectacle.

Others of a mystical bent feel less threatened by the comet, particularly because of its coincidence with Christmas. “I do not mean to suggest that another Christ will be born,” wrote James Grayson Bolen, editor and publisher of the magazine Psychic, “but rather that an inner birth of Christ-like consciousness might occur.” Imprisoned Acid Guru Timothy Leary, who was recently the beneficiary of a fund-raising “Comethon” in Santa Cruz, Calif., shares this optimism: “The Comet Starseed [Kohoutek] comes at the right time to return light to the planet earth.” Adds Carl Schleicher, whose Washington-based Mankind Research Unlimited Inc. exploits mind control and other fringe sciences: “A majority of our ‘sensitives’ have good vibrations about Kohoutek. The portents are good.”

Comets (from Greek kométés, for long-haired) have been objects of awe, reverence and fear throughout history. The ancients, at least, had a legitimate excuse for their fantasies: no one knew where comets came from or where they went after they disappeared from sight. (Aristotle suggested that they were fiery “exhalations” in the atmosphere.) Whenever a comet appeared, it was taken as a sign from heaven of impending calamity: a flood, an outbreak of disease or even the fall of a king or empire. Plutarch wrote that a brilliant comet shone for seven nights in the sky over Rome after the assassination of Julius Caesar. In Shakespeare’s dramatization of that event, Caesar’s wife echoes the same theme: “When beggars die, there are no comets seen. The heavens themselves blaze forth the death of princes.”

“Hairy Star.” According to some biblical interpretations, a bright comet appeared over Judea around 7 B.C. shortly before the birth of Jesus. Oracles told King Herod that the “hairy star” was the harbinger of the birth of a boy who was destined to outshine the monarch himself. To thwart that threat to his supremacy, Herod went on a rampage of infanticide. In A.D. 451 a comet blazed overhead as Attila the Hun overran Gaul on a march that culminated in the invasion of Italy. A comet, depicted in the famous Bayeux tapestry, also appeared in the sky on the eve of the Battle of Hastings in 1066. William the Conqueror told his Norman soldiers that the comet was indeed a bad omen—for the English troops, who subsequently went down to defeat. In 1456, Pope Calixtus was said to have been so upset by the appearance of a comet after the Turkish conquest of Constantinople that he issued a bull of excommunication against the interloper—”to rid the earth and mankind of its calamities.”

The comet of 1456 and many of the others that influenced ancient history were one and the same: the celestial visitor that became known as Halley’s comet. A 17th century protégé of Isaac Newton, Edmund Halley was convinced that comets travel, like planets, in closed orbits around the sun. Using his mentor’s formulas, he calculated the paths of comets dating back to 1337 and found that three—those of 1456, 1531 and 1607 —had roughly the same orbit as the comet of 1682 (which he had seen as a young man). Halley concluded that they were all the same object and boldly predicted that it would appear again in 76 years, the time it requires to make a single orbit around the sun. When Halley’s comet reappeared on schedule in 1758, it offered convincing evidence that comets were really members of the solar system rather than messengers of God’s wrath.

Still, fear of comets persisted. Just before Halley’s comet returned in 1835, rumors spread that it would collide with the earth. Although the path of Halley’s comet precluded collision, the possibility that a comet could strike the earth is not entirely farfetched. The earth bears the scars of at least two impacts that some scientists ascribe to comets: at the site of the Great Tunguska catastrophe, which leveled the Siberian landscape for more than 20 miles around in 1908, and in the geological formation known as the Witwatersrand gold field in South Africa. The possibility of a hit also fascinated Jules Verne. In his 1877 story Hector Servadac, the earth is smashed to bits by a comet, and the protagonists drift off into space on one of the fragments. Statistically, the likelihood of a comet colliding with the earth is extremely remote; scientists calculate that such a collision will occur no more than once every 200 million years.

Two Freaks. Cometphobia took another form during Halley’s reappearance in 1910. Fearing that mankind would be poisoned as the earth passed through noxious gases in the comet’s tail, many people bought gas masks and “comet pills” to prevent asphyxiation; they also staged a round of end-of-the-world parties. But the gases were far too tenuous to do any damage, and the earth remained unscathed. One famous prediction, however, did come to pass. Mark Twain, who had been born during the comet’s previous visitation in 1835, and wrote that he expected to die during its next (“The Almighty has said, no doubt: ‘Now here are these two unaccountable freaks, they came in together, they must go out together.’ “), died only a day after Halley’s comet made its closest approach to the sun.

Perhaps the most famous comet tale was written by Futurist H.G. Wells. In his 1906 novel In the Days of the Comet, the earth was enveloped in a mysterious green gas from a comet’s tail just as war broke out between England and France. The vapors had so beneficent an effect that the combatants fell asleep for three hours, awoke to a world without war and began building a Utopia of socialism and love. In contrast, there is the bleak view of Psychologist turned Amateur Geophysicist Immanuel Velikovsky. In his bestselling 1950 book Worlds in Collision—which is regarded as gospel by many mystics but as science fiction by most scientists—Velikov-sky blamed a near miss by a comet for such biblical events as the parting of the Red Sea and the plagues of Egypt. The fate of that comet? According to Velikovsky’s scenario, it settled into an orbit near the earth and is now known as the planet Venus.

Comets, in fact, are nowhere near as large as planets. Their central structure, or nucleus, is usually no more than a few miles in diameter; it is believed to consist largely of frozen gases—mainly water vapor, methane, carbon dioxide and ammonia, and perhaps some hydrocarbons—and dust particles. That, at least, is the commonly accepted “dirty snowball” theory, originally proposed by Harvard’s Whipple in 1950. But there are those who take exception to Whipple. British Astronomer Raymond A. Lyttleton prefers his own “gravel-bank” theory, which holds that the cometary nucleus is really a loose mass of dust particles with little or no ice. By training their instruments on Kohoutek, astronomers may at last be able to settle that argument.

There is less debate about where comets originate. The most widely accepted explanation is that of Dutch Astronomer Jan Oort, who says that comets exist by the billions in a vast swarm of debris beyond Pluto that stretches halfway to the nearest star, Proxima Centauri. The debris, called Oort’s Cloud, coalesced from the swirling dust and gases in the original solar nebula, from which the sun, earth and other planets and moons were formed. Thus comets are primordial matter, largely unchanged since the solar system’s birth. (Lyttleton ascribes a different origin to the comets: he thinks that they are swept up by solar gravity as the sun wheels around the galaxy through clouds of interstellar matter.)

Wispy Hydrogen. Tugged by the gravity of a passing star, chunks of the Oort debris are occasionally pulled into orbits closer to the sun. Then perturbed further by the gravity of a massive planet, probably Saturn or Jupiter, they often enter a highly elliptical orbit that swings them close to the sun and then so far out again that they do not return to the vicinity of the sun for years. Some, like Encke’s comet, which makes a pass around the sun every 3.3 years, have relatively small orbits. Others loop out billions of miles from the sun, and millions of years elapse before they return.

As a comet enters the inner part of the solar system, the sun’s heat begins to liberate dust and gases from the nucleus, forming a large cloud called the coma. Such clouds may become Jovian in proportions, with a diameter of more than 100,000 miles, though they are very thinly dispersed. In 1969 and 1970, NASA’S Orbiting Astronomical Observatory (OAO-2) discovered that the coma of comets is surrounded by a still larger ball of wispy hydrogen that may far exceed the sun’s diameter of 860,000 miles.

The hydrogen cloud is believed to be formed from the dissociation of water molecules in the nucleus. As the comet nears the sun, it acquires its most characteristic feature. Bombarded steadily by the charged particles of the solar wind and by the slight but measurable pressure of sunlight itself, the cometary gases and dust are swept back to form one or more glowing tails. These may reach lengths of 60 million miles or more, roughly two-thirds the distance between earth and sun. Regardless of the direction of the comet’s travels, its tail is always directed away from the sun. Thus, when Kohoutek reappears in the evening sky after swinging around the sun, its tail —which now trails the comet—will precede it as Kohoutek races away toward the outer reaches of the solar system.

Despite all that has been learned about the dynamics of a comet’s tail, its shape cannot be accurately predicted. In the late 18th century, DeCheseaux’s comet sprouted seven distinct tails that fanned out peacock-like. Some comets do not develop tails at all. As of last week, however, Kohoutek was developing a classic appendage, which should continue to increase in length and grandeur until the comet comes close to the sun. Most comets survive this relatively close flyby of the sun and emerge, sometimes altered in appearance, with even more brilliant tails. Others, affected by the sun’s powerful gravity, have broken up and vanished, as did the debris of Biela’s comet after it split in two in 1846.

It was during a search for the remnants of Biela’s comet that Luboš Kohoutek made his great discovery. Interested in the minor bodies of the solar system since boyhood meteor-and comet-hunting expeditions in the Czechoslovak mountains, he had in the fall of 1971 located a cluster of about 50 small asteroids in an orbit roughly comparable to that of Biela’s comet. Last February, using Hamburg Observatory’s 32-in. Schmidt telescope, he tried to “recapture” the asteroids, which he feels may be the remaining chunks of the lost comet. To Kohoutek’s surprise, he not only obtained pictures of the asteroids but also, during an eight-day period, discovered on his photographic plates the telltale blurs of two new comets.

Such discoveries are not unusual; as many as a dozen new comets are found each year, often by diligent amateur stargazers like Kaoru Ikeya, a worker in a Japanese piano factory. Ikeya has been finding new comets at the rate of about one a year since he and another Japanese amateur, Tsutomo Seki, independently discovered the major Ikeya-Seki comet in 1965. Kohoutek, too, had previously discovered a comet in 1969. But it was the second of his 1973 discoveries —officially called Comet Kohoutek 1973f (the ∫ indicating that it was the sixth new comet sighted this year)—that quickly created worldwide excitement.

Dirty Coat. As is customary, Kohoutek immediately sent word of the sightings to the Central Bureau for Astronomical Telegrams at the Smithsonian Astrophysical Observatory in Cambridge, Mass. Under the direction of Astronomer Brian Marsden, the bureau acts as a world clearinghouse for news of astronomical discoveries. It soon became evident to Marsden that the second comet was no ordinary visitor from distant space. After making some rush observations of his own (“We spent a very tense weekend out at Harvard Observatory’s Agassiz Station”), he reported that the comet Kohoutek had been sighted at a distance of roughly 480 million miles from earth, barely within the orbit of Jupiter. (Halley’s comet, by contrast, was not found on its last approach until it was some 180 million miles closer to earth—even though astronomers knew where to look for it.) Never before had a comet been detected at such a great distance.

The early discovery meant that Kohoutek was not only intrinsically brighter than Halley’s comet but probably quite large. Astronomer Elizabeth Roemer, of the University of Arizona, estimates that Kohoutek’s nucleus is about 25 miles in diameter, far larger than most comets, probably including Halley’s. Other astronomers calculate that Kohoutek weighs about 1 trillion tons. But size is not Kohoutek’s only distinction. It will pass within 13 million miles of the sun. That close flyby, well within the orbit of Mercury, should make for a dazzling interaction between sun and comet. Perhaps most important of all, astronomers describe it as a “dirty” comet, one with an outer layer of dust that has probably never been stripped off by solar heating. That layer may prevent the comet from becoming as bright as originally predicted. But it also means that Kohoutek may be a “virgin,” making its very first visit to the hot inner sanctum near the sun. That will give scientists an opportunity to study at close hand the structure of material that has never been heated, and thus is largely unchanged from its primordial state.

Because Kohoutek was spotted much earlier than most new comets, astronomers have had an exceptionally long lead time to prepare for a thorough examination. They are taking full advantage of the opportunity. In addition to the conventional telescopes of every size and variety that will be following the comet, NASA’S big radio telescope in the Mojave Desert will be aimed at Kohoutek in an attempt to bounce radar signals off the comet’s nucleus (those echoes may tell scientists more about the size and character of the nucleus). M.I.T.’s Haystack Radio Observatory will try a similar experiment in reverse: it will study radio waves from a far-off radio source (possibly a quasar) after they pass through the comet’s tail, in hopes of finding the spectral “signatures” of water or ammonia. If they succeed, the M.I.T. astronomers will have gone a long way toward confirming Whipple’s icy-snowball theory.

Much work will be conducted under the aegis of NASA’S Operation Kohoutek, directed by Astronomer Stephen P. Maran. Involving hundreds of scientists and millions of dollars in hardware, the observations will be largely made from above the atmosphere, which blocks out the ultraviolet and infrared frequencies useful in gathering data about the comet’s composition and structure. At least five sounding rockets and two balloons will be launched to view Kohoutek. The comet will also be chased by two highflying, instrument-crammed jets. Other information will be gathered by Copernicus, NASA’S orbiting astronomical observatory, and OSO7 (for Orbiting Solar Observatory). The Venus-and Mercury-bound Mariner 10 may be used to take high-resolution TV pictures of the comet, while either Pioneer 6 or Pioneer 8, both of which are orbiting the sun, try to determine the density of the comet’s tail by probing it with radio signals.

Scorched Planet. Kohoutek’s arrival comes at a remarkable stage in man’s exploration of the solar system. Scientists are still sifting through the mass of lunar measurements, pictures and rocks brought back to earth by the Apollo astronauts. From the data gathered by Russia’s Venera 7 and 8 landers, America’s Mariner 2 and 5 flybys, and radar observations by the Mojave telescope, astronomers can now describe in some detail the hellish surface temperature (900°F.), cratered topography and atmospheric conditions of cloud-shrouded Venus. Using the startlingly good pictures transmitted by Mariner 9, scientists at the Jet Propulsion Laboratory in Pasadena have just completed a huge model of Mars that shows craters, plains and valleys more clearly than lunar features can be seen through earth-bound telescopes.

Last week four unmanned Soviet spacecraft were about halfway along on a journey to Mars. When they arrive in February and March, two of the ships are expected to make soft landings while the other two remain in orbit around the Red Planet. Meanwhile, the U.S.’s Mariner 10 spacecraft was well on its way to Venus on the initial lap of the first two-planet, photo-reconnaissance flight. After Mariner has swept by Venus in February, using the braking force of that planet’s gravity to change course, it will pass next March within 621 miles of Mercury, the tiny, scorched planet closest to the sun.

Still another solar-system explorer, Pioneer 10, last week briefly eclipsed even the growing excitement over Comet Kohoutek. Completing a 21-month voyage across the bleak, cold reaches of more than half a billion miles of space, the 570-lb. robot gave man his first close-up look at the giant planet Jupiter. After penetrating intense radiation belts that pack radiation dosages at least 1,000 times the level regarded as lethal for humans, Pioneer passed just 81,000 miles above the multicolored Jovian cloud tops, took color pictures, gathered oth er data and then was hurled by the enormous gravitational pull of the sun’s larg est planet onto a course that will eventually carry it out of the solar sys tem, toward the stars — the first object from earth ever to embark on such a cosmic odyssey.

Hula-Hoop. “An engineer’s dream come true,” exulted NASA Boss James Fletcher. He had every reason to be proud. Pioneer had not only survived its encounter with electron intensities 1,000,000 times greater than those in the earth’s own radiation belts but continued to radio back data after the historic encounter. Indeed, if Pioneer’s tiny nu clear power packs and instruments keep functioning, the spacecraft’s signals may well be received on earth until it reaches the orbit of the planet Uranus about 14 years from now. What is more, Pioneer’s success clears the way for a twin, Pioneer 11, already en route to Jupiter and then possibly to Saturn.

The flood of data from Pioneer 10’s different instruments will require weeks and even months of detailed analysis, but project scientists last week had already made some preliminary conclusions. For one thing, Jupiter’s magnetic field—only about ten times stronger than the earth’s—follows what the scientists variously dubbed a “Saturn ring” and “Hula-Hoop” model; that is, the lines of magnetic force seem to stretch outward near the equator but are more rounded at the poles. The average temperature of Jupiter’s cloud tops is somewhat above 200°F. with no apparent variations on the day and night sides; this fact tends to confirm the widely accepted idea that Jupiter—which is so large that it barely missed generating its own nuclear fires and becoming a star —is giving off some internal heat. There was also additional proof of Jupiter’s powerful gravity. During the brief flyby, Pioneer was suddenly hit by ten tiny meteoroids, after a rate of only one hit every 25 days during its journey; this indicated that the Jovian gravitational field scoops up and concentrates the particles as the planet whirls round the sun.

To the chagrin of Pioneer’s photographic team, there was a loss of several close-up pictures, including one of the Jovian moon lo, an object of particular interest to astronomers because of its extraordinary brilliance. But other data and the color shots of Jupiter, including a closeup of the Red Spot during the flyby, fully met expectations.

After the Jupiter flyby, astronomers —including the Skylab astronauts —turned their attention back to Kohoutek. “She’s still coming at us,” reported Skylab Commander Gerald Carr, noting that the fuzzy blob was getting bigger all the time. In the weeks ahead, the Skylab crew will keep Kohoutek under virtually constant watch in order to spot any structural changes in the comet as quickly as possible. The astronauts will also lug some of their cameras outside to get the best possible pictures during three space walks—on Christmas Day just before the comet ducks behind the sun, on Dec. 29 after it reappears, and again just before the end of the mission in February.

Bit of Luck. Skylab’s presence in orbit during the comet’s passage is an incredible bit of luck. If the comet had arrived a month or so later, or Skylab had been launched only slightly earlier, the space station would not have been available for the important observations. Says Astronaut-Scientist Karl Henize: “All through the space program, we’ve been looking for a Rosetta stone—what is the primordial material out of which the solar system is made? We looked for it on the moon and we didn’t find it; we found other things instead. Now we’re down to our last chance—the comets. It’s something of a miracle that we have Skylab up there just when a bright comet like Kohoutek comes along.”

Even more of a miracle, perhaps, is the comet itself. At a moment in history when mankind seems more inclined to look inward at parochial problems, Kohoutek is a reminder of great events —and even greater mysteries—far beyond earth. How was our solar system formed? What changes will occur in the next several billion years—before the sun’s nuclear fires go out? How did life begin? The comet Kohoutek may well offer clues, if not answers to some or all of these questions. If it does, it will prove that it is indeed a messenger—of light and knowledge for all mankind.