The image is that of a powerfully built man who stood 5'10½" tall and weighed about 175 pounds. He was bearded and wore his hair long, gathered in a loose pigtail at the back, in the style of Jewish men of his time. He appears to have been crucified in a way described in the Gospels, and wore a cap or helmet—rather than a crown—filled with thorns. The man's shoulders were bruised, as if by the weight of the cross; his knees were scraped, as if he had fallen. His body was cruelly scourged, probably with a triple-thonged flagrum, a kind of whip peculiar to the Roman legionnaires of 2,000 years ago. Pinioned to the cross with two nails through his wrists and a third through his crossed feet, the man probably died from asphyxiation. He had been stabbed in the right side of the chest by a lancea of a type that was standard equipment among Roman soldiers. The wound made certain the victim was indeed dead.

This eerie reconstruction of a first-century crucifixion comes not from the New Testament or from legends spun out over the ages. It is based on a scientific investigation of an ancient piece of linen cloth that is regarded by many as the most significant relic of Christendom. Bearing the mysterious but unmistakable outline of a man, the Holy Shroud of Turin is purported to be the winding-cloth that covered the body of Christ in the tomb of Joseph of Arimathea. Last month the shroud was subjected to 120 hours of tests by 45 scientists from four countries. Heading the group was a team of 30 Americans, led by two young Air Force captains, John Jackson, a physicist, and Eric Jumper, an aeronautical engineer.

For Jackson and Jumper, both 32 and instructors at the Air Force Academy, the journey to Turin marked the climax of a remarkable extracurricular fascination. Jackson, a native of Denver, remembers being shown a photograph of the shroud by his mother when he was only 13. "I didn't recognize what it was at first," he recalls, "but slowly it dawned on me that it was the face of Jesus. I never forgot that." Years later, after his graduation from Colorado State University, Jackson was working toward his master's in physics when his interest in the shroud was rekindled during discussions about religion with friends. Belief in its authenticity appealed to him, but he was goaded by doubts. In 1974, when he was engaged in laser research at Kirtland Air Force Base in Albuquerque, Jackson concluded that space-age technology could shed new light on the ancient mystery of the shroud. His mission had begun.

Jackson's enthusiasm proved contagious. "John hooked me," says Jumper, who as the engineer was responsible for putting Jackson's hypothetical experiments on the shroud into practice. "We complement each other, but we sometimes knock heads. John thinks up all these interesting, complicated and expensive ways to test things, and I come up with something that is workable and cheap." When both men were transferred to the Air Force Academy, they were able to continue their research—at their own expense, on their own time.

By then even Jackson and Jumper were startled by their success. With a computerized image-enhancing device that NASA used to clarify photos of Mars and other celestial bodies, the two men were able to bring out details of the figure on the shroud which had never before been identified. (Among their discoveries: button-like objects on each of the eyelids. Two thousand years ago, they learned, coins were customarily placed on the eyes of the dead.) They determined that the image is three-dimensional, anatomically correct and curiously similar to a photographic negative—findings that have all but repudiated most of the popular explanations of the shroud as a hoax. For Jackson, a Roman Catholic, the discoveries were unsettling: "It suddenly hit me that we might really be examining the burial cloth of Jesus. I nearly fell over." Jumper, a nondenominational Christian, was even more unnerved: "It made me feel uncomfortable. I had been working on the shroud simply because it interested me, but suddenly there were deep philosophical questions. There was a
burden of objectivity on what we were doing."

Jumper and Jackson were not the first to feel that disquieting burden. Ever since the shroud was rediscovered in France 600 years ago, it has been venerated as the actual burial linen of Christ, denounced as a forgery and puzzled over by believers and skeptics, scientists and theologians. Though burned and patched, it has survived both a flood and an earthquake and is remarkably well-preserved. Since 1453 it has belonged to the House of Savoy—the royal house of Italy until 1946—and has been kept in a triple-sealed sepulcher in a special chapel in Turin's Cathedral of St. John the Baptist. In 1898 the shroud was exhibited to the public and photographed for the first time. Remarkably, negatives of the image registered as positive, and positive prints revealed a ghostly, stunningly detailed likeness of the man presumed to have been wrapped in the shroud. The theory that the image might be simply a painted forgery was finally laid to rest: No known pigment could be identified, and the image appeared only on the surface of the linen cloth. Paint would have soaked into the fibers. Still, the baffling question remained: How was the image created? The answer may have been provided 47 years later at Hiroshima, when the images of incinerated atom bomb victims were emblazoned on rocks and metal by the intense light. The explanation for the shroud—now widely accepted by scientists—is that the Christlike figure is a negative image of the body the cloth once contained, seared onto the fabric by a burst of light, in a process called flash photolysis. Experts sensibly decline to speculate whether the "flash" could have been the blinding light, described in the Gospels, at the moment of Christ's resurrection.

Could the mysterious image at Turin be a kind of photograph of Jesus himself? Only this much is apparent: It is the figure of a man who was crucified and who bears all the marks of the Passion of Jesus as described in the Bible. Unfortunately, the antiquity of the shroud itself has never been firmly established. Its history prior to 600 years ago is fogged in myth and hearsay. Allegedly, the shroud was taken to what is now the Turkish city of Urfa by Thaddaeus, a lesser disciple of Christ. There it is said to have been sealed in a wall for 525 years before coming into the possession of the Christian kings of Byzantium, and later their Muslim conquerors. Eventually, so the legend goes, the shroud was stolen by the Knights Templar and held secretly in Constantinople for centuries before it finally reappeared sometime between 1357 and 1370 in France. It was in the possession of a family thought to be descended from a Crusader. Carbon-14 tests of the cloth—to authenticate its true age—have been postponed by Archbishop Anastasio Ballestrero, the shroud's present custodian, because they would require the destruction of a large swatch of the material. Over the years, however, experts in sindonology—the study of shrouds—have declared the fabric to be similar to existing burial linens dating back 2,000 years and more.

Intrigued by such information and by their own scientific conclusions, Jackson and Jumper applied for permission to examine and test the shroud after they learned it would be displayed publicly this year for the first time since 1933. Permission was granted, and after three months of anxious preparation, the American scientific team arrived in Turin last month with 8,000 pounds of crated instruments. For five feverish days and nights the shroud was subjected to dozens of tests, including X-ray fluorescence analysis, an optical spectrum scan, and infrared and ultraviolet ray analyses. Every square inch of the linen was photographed, with film especially created for the project by Kodak and Polaroid, for further computer study.

At the very least Jumper, Jackson and their colleagues hope to discover the source of the intense energy that scorched the image onto the cloth. But the final analyses and experiments will take many months and cost some $250,000, which the scientists hope to raise through donations and grants. Their conclusions will eventually be published, but whether the shroud of Turin will finally yield up all its mysteries is as moot a question now as it was 600—or perhaps 2,000—years ago. John Jackson is not a skeptic. "After reviewing the evidence," he says, "and personally seeing the shroud, I genuinely believe it is the burial linen of Jesus."