Marsden is confident that his small crew can keep an eye on things for now, but he says more funding is required to hire two more people, as well as someone to maintain the sometimes-glitchy computer system that processes asteroid data and supplies the follow-up observers with the data they need to go hunting.

Delays of 24 hours or more have occasionally occurred in the past, Marsden said, due either to computer problems or the fact that he and his two colleagues are putting in seven-day weeks in an effort to keep up.

The growing workload has begun to generate tension and cause workers to snap at each other -- something that never used to happen, Marsden said.

Meanwhile, the Minor Planet Center's funding is dropping. The bulk of its money has traditionally come from subscriptions to its publications of asteroid data. But with the transformation from printed to electronic publishing, fewer research institutions, libraries and individual astronomers are willing to pay for the data.

David Morrison, an asteroid researcher and director of the space program at NASA's Ames Research Center in California, agrees that the increasing pace of discovery may overwhelm the cadre of amateur astronomers doing follow-up observations, no matter how well equipped they might be.

Morrison said that any asteroid aiming for Earth can be discovered decades before the impact, assuming it is bright enough to be picked up with current search telescopes.

"The problem is not that we won't see it soon enough," he said. "The problem is that we won't spot it at all."

But once an asteroid is discovered, Morrison said, there's no reason it can't be properly processed. Morrison thinks management of the growing bounty of data needs to extend beyond the Minor Planet Center.

"We'll need to distribute the workload among a number of international organizations that already have the capability to process these data," Morrison said.

At least three organizations around the world have the needed computer programs. One, in Arizona, is called the Lowell Observatory Near-Earth-Object Search (LONEOS). Lowell scientists used to process their own asteroid data, but a grant that funded the effort was not renewed. So now they are forced to forward mostly raw data to the Minor Planet Center.

Bruce Koehn, a research scientist who does the programming for the LONEOS effort, said his colleagues would prefer to process their own data. He said there are several reasons why distributing the workload is a good idea.

"The Minor Planet Center can easily become overwhelmed," Koehn said.

Equally important, he said, is that having multiple groups do the calculations provides a check and balance for overall accuracy. It also creates an environment where new and improved methods will be developed by one group and adopted by others.

Regardless, the future might not be as grim as others think, according to Koehn.

Most large asteroid survey programs do some of their own follow-up work, he said. As the pace of discovery increases, he thinks these survey teams will be forced to do more of their own follow-up. And other search projects currently in the planning stages have included follow-up observing as part of their strategy, he said.

In addition, two groups currently do some calculations that contribute to the overall knowledge base and double-checking. One team is at the University of Pisa and another at NASA's Jet Propulsion Laboratory.

Some researchers say the Minor Planet Center should remain the hub of asteroid information.

"The Minor Planet Center has the expertise, links and contacts," said Jonathan Tate, founder and director of Spaceguard UK, an group that advocates increased search efforts. "They are a central node, and to distribute this would produce further complications, both practical and organizational."

Tate agreed that more funding is needed to allow the center to keep pace.

One way to cope with the increasing workload is to fund and foster greater international cooperation and new search projects, several experts say. Efforts are under way to establish a multinational professional search program in Europe, says Peiser, the UK researcher. The idea was jumpstarted last year when a task force set up by the British government recommended sweeping changes to how governments should view the threat of asteroids.

Among the official recommendations of the task force:

"We suggest that the United Kingdom and other governments, together with the International Astronomical Union, NASA and other interested parties, seek ways of putting the governance and funding of the Minor Planet Center on a robust international footing, including the Center’s links to executive agencies should a potential threat be found."

The Minor Planet Center has not yet benefited from the call to action.

Meanwhile, astronomers around the world grapple with a simple fact: They cannot see most asteroids smaller than 1 kilometer until they are relatively nearby. The technology exists, but it has not been devoted to the task. The reason goes back to decisions made roughly a decade ago.

Early discussions spearheaded by NASA resulted in the goal of finding 90 percent of all Near Earth Asteroids in a decade's time. Scientists talked of setting the limit lower, to include objects down to 100 meters, but they knew that would have meant finding a lower percentage of the many more objects they'd be looking for. Several scientists involved in the discussions argued that the bulk of the danger rests with asteroids larger than 1 kilometer anyway.

As Morrison puts it: "Only these can create impacts that could have global consequences and perhaps end civilization as we know it."

So NASA funding for asteroid search programs today is driven primarily by the goal of finding objects 1 kilometer or larger. Many smaller objects are found in the course of these searches. But some researchers think it is time to begin focusing on the smaller rocks.

"We need bigger telescopes to come down to the 100-meter limit," Tate said. "There is a substantial risk from undetected 100-meter sized objects."

If Tate gets what he wants, then Marsden's prediction of 200,000 numbered asteroids by 2004 would later be superseded by quantities about which no one is willing to venture a guess. Millions of small asteroids are thought to exist.

"Then things will really start booming," Marsden said.

Which would, of course, greatly exacerbate the problem of follow-up observations.

"The amateurs doing follow-up are doing sterling work," Tate said, "but it is a bit odd that something as important as this is not a matter for official interest."