The new telescope will be used exclusively for asteroid searches, relocating objects that have become, quite literally, lost in space, and for keeping an eye on the whereabouts of newly found objects.

"That will make it the largest telescope in the world dedicated full-time to that exclusive purpose," McMillan said.

The Spacewatch Project has been exploring the whole solar system for some two decades -- from the vicinity of Earth's orbit out to Neptune's -- to find objects, how they got to be in those orbits and to better determine how the solar system evolved.

"Right now, we're finding, on average, about two near Earth asteroids per month," McMillan said.

With the new telescope, along with new electronic devices outfitted to the existing telescope, the Spacewatch Project enters a new observing realm.

"We should be discovering objects much faster, perhaps as many as 20 per month. We'll be busy," McMillan said.

Jim Scotti, a Spacewatch Project researcher, said the more sensitive upgrades and newer equipment would permit Spacewatch to carry out studies more effectively.

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The ability to detect fainter objects will allow Spacewatch to find smaller asteroids nearby, as well as smaller and even more distant bodies in the solar system's outback, Scotti said. With the larger telescope, completion of the Near Earth Asteroid survey, including rocks as small as approximately one half mile (0.8-kilometer-) in size, can be more easily accomplished, he said.

The main goal of Spacewatch is to spot comets and asteroids that might be potentially dangerous objects, well before they pose a threat to Earth.

These big bruisers have bombarded Earth before and they will wallop the planet again. It's just a matter of when, Spacewatch officials admit.

Even now, there are several asteroids that look menacing. They have orbits that could make them dangerous sometime in the future.

As many as 900 large asteroids, more than a half-mile (one kilometer) in size or greater, float through the inner solar system and are a possible threat to Earth.

Like many things, in the case of asteroids, size counts too. A space rock more than half a mile across that slams into Earth can wreak global havoc.

"One of the challenges to the whole asteroid community is to find out how many of these objects there really are," said Robert McMillan, director of the Spacewatch Project here at the University of Arizona's Lunar and Planetary Laboratory. "Knowing the number of Earth-approaching asteroids, then we can quantify the impact hazard," he said.

Atop nearby Kitt Peak, the Steward Observatory 36-inch (0.9 meter) Spacewatch telescope is busy. Observers using that instrument and associated equipment are playing the numbers game. They try to count small objects in the solar system.

The statistics of how many asteroids and comets are found helps to gauge just how dynamic the planetary neighborhood really is, McMillan told SPACE.com. "You can observe a certain amount of sky, find a certain amount of objects, then extrapolate that number to estimate the total size of the population," he said.

McMillan said that if there was just one supply of near-Earth asteroids billions of years ago, they would have been all swept up by now. By crossing the orbits of Mars and Earth, and sometimes swinging by Venus, asteroids wouldn't stay in their orbits for very long. They would be scattered away, he said.

"So where are the near-Earth asteroids coming from?," asks McMillan. They must be raining down on us from the main-belt asteroids between Mars and Jupiter, he said.

Likewise, Centaur-class asteroids are raining down from the Kuiper Belt beyond Neptune.

"So the whole solar system is constantly in change and in a state of flux. That's completely different than what was thought in the 19th century, which is that these orbits were stable," McMillan said.

"So we're doing science. Sometimes that message doesn't quite get across. Detecting hazardous asteroids is one of our many roles," McMillan said.

Scotti said the work the group carries out is unique. "We are not just surveying for the next impactor, but we're also trying to learn just how all of the different populations of small bodies in the solar system interrelate and what that will tell us about the formation and evolution of our solar system," he said.

McMillan and Tom Gehrels, also an astronomer at the university's Lunar and Planetary Laboratory founded Spacewatch in 1980.

For Gehrels, there is a haunting obligation for the Spacewatch Project to keep on the lookout for asteroids and comets harmful to Earth.

"The chances are one in 10,000 that in your lifetime you would see this [an impact on Earth], and it would be horrific," Gehrels said. "I do consider it a serious problem in terms of numbers," he said.

"We had this idea long before anybody else. Spacewatch was to do statistics, not to work on hazards. But the hazard aspect came in immediately," Gehrels said. "Though we didn't realize it in our guts, our minds had set us on this path, to go after this and take care of it as part of the statistics work," he said.

Finding objects that might present a hazard to Earth has not been work fully embraced by the scientific community, Gehrels said. Back stabbing, outright hatred, and maybe touches of jealousy by other scientists have been stirred up over the years as the Spacewatch Project moved forward, he said.

"I've been described as the only astronomer who lies awake over this problem. And I've admitted to that," Gehrels said. "But the more precise reason for lying awake is how to get the funding to do the Spacewatch Project," he said.

The Spacewatch Project, Gehrels said, does not need much money. Finding a private donor who will support the effort is on the order of $300,000 a year is all that's needed.

At present, Spacewatch funding is one-half to two-thirds federal monies, and the rest private foundations and personal contributions, McMillan said.

"If he doesn't find it, he may go under. It would be like a house of cards," Gehrels said. "That's been the story right from the beginning," he said.