In a sunlit gallery of the Museo Archeologico Nazionale in Italy, astronomer Brad Schaefer came face to face with an ancient statue known as the Farnese Atlas.
For centuries, the 7-foot marble figure of the mythological Atlas has bent in stoic agony with a sphere of the cosmos crushing his shoulders.
Carved on the sphere -- one of only three celestial globes that have survived from Greco-Roman times -- are figures representing 41 of the 48 constellations of classical antiquity, as well as the celestial equator, tropics and meridians.
Historians have long looked on the Atlas as a postcard from the past -- interesting largely as astronomical art.
But as Schaefer approached, he began to notice subtle details in the arrangement of the constellations. It wasn't that anything was wrong with the statue. If anything, the positions of the constellations were too perfect to be mere decoration.
He was more than a little intrigued. No, this was no mere piece of art. Taking out his camera, he was about to take a journey through the centuries to unravel one of the great mysteries of the ancient world and uncover key evidence in what may be one of the biggest cases of fraud in the history of science.
You might call Brad Schaefer a detective to the stars.
That's Antares, not Aniston. Betelgeuse, not Michael Keaton.
When Schaefer's not cramming Astronomy 101 into his students at Louisiana State University in Baton Rouge, he is chasing his quarry across the starry landscape like a celestial Sherlock Holmes.
Over the course of his career, he has written more than 250 articles on such quirky subjects as how the stars influenced Egyptian civilization and why people seem to kill themselves when Halley's comet comes around.
"I like to tell stories," he said.
Dressed casually in tennis shoes and loose clothing, he looks younger than his 48 years. Backyard inventor, chess expert and former world-ranked tiddlywinks player, the MIT graduate can seem the stereotypical absent-minded professor and perpetual adolescent.
But behind that mop of blond hair and the twitchy mannerisms is the bulldog temperament of a big-city homicide detective.
A few years ago, he decided to try to determine the actual date of Christ's Crucifixion using purely scientific methods. He wrote a computer program that factored in all the astronomical data he could unearth from the time. Then, because the Crucifixion is thought to have taken place 14 or 15 days after a crescent moon first became visible, he added in thousands of modern records of atmospheric haze to approximate periods of high and low visibility in the ancient Middle East.
Rolling back the calendar more than 1,900 years, he came up with two dates: AD 30 and 33.
Bible scholars, comparing biblical texts with historical records, have arrived at similar dates.
Schaefer thinks his results are more reliable. "People in the past never tried doing physics-based research," he said.
Schaefer wasn't looking for another mystery when he and his wife, a planetary geologist, took a Mediterranean cruise in June.
The purpose was to view the transit of Venus -- a rare astronomical event in which the planet crosses the face of the sun.
Schaefer decided to pay a visit to the Museo Archeologico Nazionale in Naples.
He knew something of the Farnese Atlas, named for Cardinal Alessandro Farnese, who purchased it in the 16th century. The statue, probably a Roman copy made about AD 150 of an earlier Greek statue, is the oldest representation of the original Western constellations.
There are no stars on the globe, just the constellations themselves, represented by earthly forms such as a ram, a bull or a huntsman. Even so, he could tell that they were laid out with great precision. If the globe was accurate, he realized, the heavenly scene depicted on its surface would conform to only one moment in history. And thus reveal for the first time its origins.
But how to find that moment? It wasn't as simple as rewinding the celestial clock. This time, he had to guess the position of the stars within those earthly forms, from the position of a horn or a hoof.
Few astronomers would have thought it possible.
To Schaefer, that just made the task more interesting. He returned to Louisiana to begin the painstaking work of finding his way back through the fog of time.
In antiquity, man tried to make the night sky familiar by stitching stars into constellations.
Mesopotamians created zodiac signs as early as 1100 BC. Some Chinese constellations are 2,000 years older than that.
The world's oldest constellation is thought to be the Big Bear, which we know as the Big Dipper. Schaefer traced it to an Ice Age bear cult from 14,000 years ago.
A few hundred years before Christ, a handful of stargazers began looking beyond the pictures in the sky to the actual mechanics of the cosmos.