TUCSON, Ariz. -- Robert A. Haag owns a piece of the moon, and he may be the only person in the world who does.
Mr. Haag is a 35-year-old entrepreneur who has amassed what experts consider the best and largest private collection of meteorites anywhere on the globe, some of which he sells to collectors around the world. While adding to his collection in Australia a year ago, he came across one tiny specimen that looked different from all the others.
He filed off one edge of the 19-gram stone. "I knew immediately it was lunar," he said in the huge vault beneath his home on the outskirts of Tucson, where he keeps his collection of thousands of meteorites.
"I almost passed out," he said. "It was mine."
He sliced off a small piece of the meteorite and took it to the Lunar and Planetary Laboratory at the University of Arizona. The lab had determined several years ago that a dozen rare meteorites found in Antarctica had come from the moon.
Researchers Dolores H. Hill and William V. Boynton were astonished when they found that the meteorite was rich in lunar materials and contained a ratio of certain chemicals that "leave no doubt whatsoever that this is lunar," Ms. Hill said.
Ms. Hill and Mr. Boynton published their findings in a recent issue of the British journal Nature.
The meteorite is the only lunar rock found on the Earth outside Antarctica. Meteorites in general are easier to find in areas -- such as Antarctica -- that have not been cultivated and do not have extensive vegetation or urbanization.
Lunar meteorites are created when some other celestial body -- possibly a small asteroid -- collides with the moon so violently that debris is sent flying off into space; some become captured by the Earth's gravity. In this case, one meteorite traveled to the Earth and landed in the Australian outback, where it remained unmolested for years in a region known to be rich with meteorites.
Mr. Haag did not actually find the lunar meteorite himself. It was one of hundreds of rocks turned over to him by local Aborigines who left their jobs to search for rocks for the American.
The only lunar meteorites found before Mr. Haag's were those discovered in Antarctica several years ago, and they belong to the governments of the United States and Japan.
Mr. Haag, a self-taught expert who got interested in meteorites when his parents ran a rock shop in Tucson, has the only one in private hands.
Mr. Haag said he has not decided what to do with his meteorite yet. But he believes it is worth a fortune.
The discovery is the second major turning point in his life in as many years. The first was when he got arrested in Argentina.
Mr. Haag had purchased a 37-ton meteorite, one of the largest in the world, from a source in Argentina, where he had collected samples during four previous trips. Unfortunately, it turned out that the person who sold him the rock had no right to do so.
So Mr. Haag spent six days in the local jail while the matter was sorted out. Eventually, it was termed a "misunderstanding."
News accounts spread around the world, and Mr. Haag said his business just boomed.
"It was the best thing that could have happened to me," he said. "Last year we grossed over $1 million" by selling meteorites.