Bouncing back and forth between a California trailer park and his Arizona desert observatory, a 42-year-old Chinese-Canadian with four Centurion telescopes has discovered 1,700 distant asteroids, one comet, and a mystery object that made him world-famous for a few days.
Professional astronomers showed this week that the bright, quick-moving mystery orb called J002E3, initially put forward as a candidate for Earth's second moon, was actually covered in titanium-oxide paint; it almost certainly is a piece of a Saturn V Apollo rocket.
This revision, however, hardly tarnishes William Kwong Yu Yeung's accomplishments; his commitment to finding things nobody else has seen simply awes people who know him.
"In my 25 years worth of customers, I have never seen anyone so dedicated as he is, and he has the talent and the results to back up that dedication," said Jim Riffle, president and owner of the firm that sold Mr. Yeung his 46-centimetre telescopes.
His efforts hearken back to an earlier, romantic period of science where ordinary people looking into the sky could make significant contributions to human understanding. Mr. Yeung knows that.
"I showed you can still make contributions even if you are an amateur astronomer," he said in a telephone interview from the El Centro, Calif., trailer park.
His decision to devote the last several years of his life to searching for asteroids fulfills a childhood fantasy. Young Bill Yeung came across a book on astronomy that stated that 1,600 asteroids had been discovered. "And I remember saying to myself at the time, it would be a good thing if I could discover one more," he said.
Advances in technology and his willingness to spend a lot of money on a hobby pursued by perhaps 100 other people have enabled him to find more than one.
When pressed, Mr. Yeung admits to having at least $400,000 (U.S.) tied up in equipment and observation sites.
While most amateur astronomers are content with a single telescope, Mr. Yeung opted for four.
The telescopes alone cost $29,000 each and record everything electronically in the manner of a digital camera.
Modern technology allows Mr. Yeung's nightly observations of hundreds of possible asteroids to be automatically given sky longitude, latitude and time readings which are then transferred, over the Internet, to the Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, Mass.
They are run through computer software to compare their orbits to those of the 48,320 asteroids already identified. The software, rather than Mr. Yeung, determines whether an asteroid is new.
How does he afford his expensive hobby? "To make life easy, you can say that I come from a well-to-do family," he coyly answers. He suggests that the initial affluence was augmented by trading on the stock market in the 1990s and trying to imitate the successes of one of his heroes, investor guru Warren Buffett.
Mr. Yeung, who was born in Hong Kong and has a degree in civil engineering from the University of Alberta, was so taken with Mr. Buffett that he tried to name one of the asteroids he found after him. The international naming committee turned him down, judging Mr. Buffet to be too much a plutocrat and not enough of a philanthropist.
Mr. Yeung has been successful in naming other asteroids: for director Steven Spielberg; for Terry Farrell, the actress who played Jadzia Dax in the television series Deep Space Nine; and for his own mother and father.
But as he prepares to return to Hong Kong for a family reunion, he admits he is at something of a hobby crossroads.
"I may have reached a point where discovery of another asteroid in the main asteroid belt is no big deal; it's just, you know, another one," he said.
The man who wanted to find one asteroid now dreams of becoming sort of a small amateur astronomical research company. He wants to hook up his financial wherewithal with a retired person in Arizona willing to operate telescopes, and link that to someone with a good viewing site and someone else with technical skills to do a joint astronomy.
Once in place, the collective search for asteroids could continue, but amateur explorer extraordinaire Bill Yeung could go on to other things.