Michael Brown, a sandy-haired Caltech astronomy professor, had been following a tiny speck of light at the fringes of the solar system for months.
Tiny, maybe. Unimportant? Hardly. The object was one of the brightest objects in a distant region of the solar system known as the Kuiper Belt, and Brown knew it was sure to cause a scientific sensation.
Just before he was to announce his discovery, an obscure group of Spanish astronomers beat him to the punch, claiming the new planetoid as their own.
"My first reaction was, 'Oh, somebody found it,' " Brown said. "I sent an e-mail congratulating them."
Within days, however, the discovery touched off a bitter feud over scientific ethics in the Internet age that continues to reverberate, with verbal fusillades fired across the Atlantic.
American researchers said they discovered that the Spaniards, led by Jose Luis Ortiz, used the Internet to peek at computer files showing where Brown was aiming a Chilean telescope.
Ortiz argues he has done nothing wrong, and the data he found using the Google search engine should be considered public and thus free to use.
"If ... somebody uses Google to find publicly available information on the Internet and Google directs to a public Web page, that is perfectly legitimate," Ortiz wrote in an e-mail to The Times. "That is no hacking or spying or anything similar."
But Brown said the incident should be taken as a warning of the porous and slippery nature of Internet research.
"This is a wake-up call for scientists," Brown said. "It's really scary."
The object at the center of the dispute is only about 1,000 miles in diameter. It had been photographed numerous times in the past, although no one realized it was a planetoid.
Finding such small objects is painstaking work, requiring the monitoring of objects over time to determine their orbit by analyzing minute movements.
Nobody did it better than Brown.
The son of an engineer on the Apollo space program, it was inevitable that Brown would develop an interest in space. After landing at Caltech as an assistant professor, he decided to devote himself to uncovering the secrets of the solar system.
Though some colleagues tried to discourage him, he focused on the Kuiper Belt, the band of asteroids and comets inhabiting the region beyond Neptune.
Since beginning his sky survey seven years ago, Brown has found 60 new objects, winning an international reputation for him and his team.
In December 2004, Brown and his colleagues, David Rabinowitz of Yale University and Chad Trujillo of the Gemini Observatory in Hawaii, believed they were close to showing that one speck in the sky was a trans-Neptunian object -- a body circling the sun beyond the orbit of Neptune.
They whimsically nicknamed it Santa and spent the next seven months learning everything they could about the planetoid.
They found that the cigar-shaped Santa spins so fast that it makes a complete revolution every four hours.
"It's the fastest thing in the solar system," Brown said.
Though not as large as Pluto, the object fascinated him because it was the only trans-Neptunian object known at the time to have a moon, which they nicknamed Rudolph.
On July 20, the team made a decision that triggered the imbroglio.
They sent off an abstract about Santa and Rudolph to the American Astronautical Society for presentation at the group's November meeting.
The abstract, which was published on the Web, contained little information about Santa but included the code they used to identify it during their astronomical observations: K40506A.
A few days after the abstract appeared, Ortiz's student, Pablo Santos-Sanz, brought him pictures taken at the Sierra Nevada Observatory in Spain of an object that he thought might be a trans-Neptunian, according to an account Ortiz posted on a message board for the International Astronomical Union's Minor Planets Center.
"We realized the object was very bright and could be the same one mentioned in ... [an] abstract Web page," Ortiz wrote.
Ortiz's team Googled K40506A. One listing that popped up was for the Cerro Tololo Inter-American Observatory, which Brown had been using to track Santa and Rudolph.
Unknown to operators of the telescope's computer system, some information -- including the observing logs and telescope pointing coordinates -- was accessible to outsiders.
Ortiz wrote that his group found records of Brown's search and realized they had seen the same object.
On July 27, they reported the discovery to the planets center, which announced the find, provisionally naming the planetoid 2003 EL61.
Brown said his first reaction was irritation at himself for not finishing his work earlier and announcing the planetoid himself.
In a bit of a panic, he called a press conference on July 29 to announce two other discoveries: a planetoid similar in size to Santa and another, as much as a third bigger than Pluto, that he called a potential 10th planet.
His discovery put his name in the history books.