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In Deep Impact and Armageddon, last year's two Hollywood fantasies about asteroid-caused extinction, it's Americans who take the lead to save the rest of the planet from catastrophe. In real life, the people who've embraced the greatest responsibility for saving Earth hail from a more specific location. Arizona. Arizona scientists...
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In Deep Impact and Armageddon, last year's two Hollywood fantasies about asteroid-caused extinction, it's Americans who take the lead to save the rest of the planet from catastrophe.

In real life, the people who've embraced the greatest responsibility for saving Earth hail from a more specific location.

Arizona.
Arizona scientists have been among the most important figures publicizing the dangers of asteroid collision, searching for the next doomsday rock, and planning ways to save the Earth from a planetoid heading its way.

Last year, it was an Arizona scientist, James Scotti, who spotted an object named XF11, a mile-wide boulder that seemed to be headed for a possible collision with Earth in the year 2028. Scotti works at Spacewatch, an Arizona project begun nearly 20 years ago by Tom Gehrels, an astronomer who has labored as earnestly as any scientist to make the world aware of the threat of asteroid collision.

The day after the dramatic announcement of XF11's discovery, refined orbit calculations showed that the rock will actually sail past us with a comfortable million-kilometer margin.

However, if XF11 really were on a course to smack into our planet three decades from now, world governments would have scrambled to direct it out of the way. And they would have used plans developed in part by Spacewatch's Gehrels.

With the recent explosion of public interest in asteroids, Spacewatch and other asteroid-hunting programs such as the Lowell Observatory Near-Earth Object Search (LONEOS) in Flagstaff have enjoyed a sudden celebrity status.

That's quite a change for a branch of science that had been treated as a kind of poor stepchild by the rest of astronomy. After years of toil in obscurity and under meager budgets, Arizonans were poised to reap the benefits of asteroid-mania.

Asteroid hunters had finally hit the big time.
Then, quietly, their labors were stolen from them.
With no fanfare, a secretive operation developed by the Air Force began dominating the field of asteroid and comet detection. Now, with equipment developed at costs they won't discuss, a small group of Air Force technicians using a single, modest-size telescope in New Mexico has almost completely taken over the responsibility of mapping the Earth's neighborhood in space.

The Air Force's astounding success is great news for the planet, of course, and the public can rejoice that the military program scans so much of the sky night after night. But for Arizona astronomers who had invested their careers in finding hazardous asteroids, losing out to Air Force spy satellite engineers has a bittersweet taste.

It will be Air Force technicians, not Arizona astronomers, who will most likely tell Earthlings when they can expect Armageddon.

They promise not to hold back any secrets.

Tons of creaking metal are on a collision course with a startled photographer, and if he doesn't scramble out of the way, he might likely be pulverized.

With a nervous giggle, the photographer grabs his gear and scurries along the wooden floor to get out of the way of the moving steel walkway headed right for him.

Meanwhile, Tom Gehrels pushes buttons on a large metal control box at the Spacewatch telescope housed in a dome on Kitt Peak in southern Arizona, and seems oblivious that he'd nearly crushed someone by rotating the telescope into position.

"Every half-hour, I dash up here to move the telescope and check it with a flashlight," Gehrels narrates in his Dutch accent. "It's pitch dark. But the telescope cannot hit any of the steel struts of the dome or that would be the end of the whole project."

Gehrels watches carefully as the telescope--as tall as a house and big around as a car--shifts position, making sure it doesn't go near various steel gussets holding up the dome. Then he leans over and says knowingly: "I was watching him, incidentally. I would not have hit him. I could see that he just got out of the way in time."

"Sorry," he says to the photographer, who shakes it off good-naturedly.
Gehrels seems to enjoy the episode. For several hours, the astronomer dances around the 79-year-old telescope, moving it into position and then dashing downstairs into a control room to begin another search for dim points of light. The slender, flaxen-haired astronomer seems to relish catching his guests off guard with his dry sense of humor.

Only five years younger than the old telescope, Gehrels defies his age by nimbly twisting and leaping around the instrument to position it to explore new swaths of sky. The Spacewatch scope is computerized, but if it isn't watched closely, it's likely to plow into one of the steel struts or, as happens a few minutes later, dump its guidance system and stubbornly refuse to budge. But Gehrels never seems discouraged. He clearly enjoys coaxing the aging equipment and delights over what pops up on the computer screens below.

For decades, Gehrels has pursued a branch of astronomy that has, until recent years, garnered little attention or hoopla. But eventually, with the efforts of Gehrels and others, his passion--asteroids and the threat they pose to Earth--began to grip the public's imagination. Then, seemingly overnight, it became all the rage.

As a result, Gehrels has been featured in dozens of articles as The Man Who Would Save Earth.

"Have things changed because of the movies? I don't know," Gehrels says. "I cannot tell that. Things may have changed because of XF11. That did bring a scare or a realization. I think the upshot of that event was, well, it didn't happen this time, but it could have, and the next time it could be for real. And that would penetrate more than anything before in Washington, D.C."

Since the public--and Congress--has become more aware of the threat posed by asteroids, NASA has increased its funding to programs like Spacewatch. But for such a high-tech enterprise, Spacewatch makes do with surprisingly low-tech equipment. That's a trait of asteroid astronomy, which has endured a second-class status in the study of the cosmos.

Prestige and dollars have tended to go to scientists trying to answer the really big questions, such as the age and fate of the universe. That endeavor requires huge ground-based instruments, as well as the Hubble Space Telescope, which examine galaxies at the far reaches of the visible universe.

By comparison, Gehrels and his colleagues have worked in relative obscurity, using modest equipment, mapping space boulders in the Earth's cosmic backyard. One of those boulders, however, is on a collision course with Earth. There's no doubt about it, scientists say. The only question is how long we have--30 years or 30 million? To answer that question, Gehrels dances around his telescope to make sure it doesn't run into its own dome, and stares at computer screens all night, looking for wayward asteroids.

Think of him as the solar system's air traffic controller, monitoring the flight paths of thousands of objects to make sure none of them has our name on it.

In the meantime, Gehrels has to put up with a nearly constant parade of reporters who insist on sitting up all night with him. So many journalists have made the trek to Kitt Peak to interview him, Gehrels begins answering questions before they're asked.

Bad reporting, he says, has led to several misconceptions about the threat asteroids and comets pose to Earth. For one thing, he says, the public has been misled about the likelihood that life will be wiped out in the near future by a hurtling planetoid.

It's far more likely than people imagine, he says.

The solar system today is misleadingly calm.
In its early history, the Earth's neighborhood was more like a cosmic billiards game, with planetoids running into each other with cataclysmic results.

For proof, just aim a pair of binoculars at the Moon some night. Pockmarked like a celestial battleground, the airless, lifeless body bears witness to eons of destruction.

Gradually, large conglomerations of those early planetoids stuck together, swept up even more material, and were shaped by gravity to become the planets that we know today. Gravity also ejected some of the early planetoids, and many were left in a band of material between the planets Mars and Jupiter known as the Asteroid Belt. In the meantime, the major planets were occasionally cold-cocked by hurtling asteroids and comets. One such collision, goes a popular theory, tore off a huge piece of Earth-stuff that eventually became the Moon. In recent times--the past billion years or so--the pace of such collisions has slowed as the solar system has become a more peaceful place. But the collisions have not stopped.

Traveling in paths around the Sun, some asteroids follow orbits that take them into the Earth's realm of the solar system but not close enough to be a hazard. But those orbits can change. The strong gravitational pull of Jupiter, for example, can influence asteroids and comets and put them on a new course and a future date with disaster.

Scientists have long known that the Earth was subject to annihilation in its history. But erosion by wind and water has erased most of Earth's scars--Meteor Crater near Winslow is an exception--and it was easy to ignore that the planet could take another hit in the future.

That view eventually changed. And it all began with a discovery not by astronomers but by a geologist.

In the 1970s, Luis Alvarez and his physicist father, Walter, made a stunning discovery. Like other geologists, Luis was familiar with a layer of dark earth, present all over the globe, that scientists used to mark the boundary between two geologic periods. When he and his father analyzed the layer, however, they realized that it contained high concentrations of a rare element, iridium, which is more common in meteors than it is on Earth. In 1979, Walter proposed to other scientists that the dark layer suggested the planet had taken a massive hit by an asteroid. The impact was so huge, the asteroid was pulverized and its material deposited across the Earth, eventually resulting in the dark layer.

The Alvarez theory was met with pessimism by astronomers. But another group of researchers--paleontologists--took notice.

The boundary that Luis Alvarez had analyzed happened to mark a period 65 million years ago, precisely the time when nearly all of the planet's dinosaurs and other large animals had died off in a mass extinction. Had the impact that laid down the dark layer also killed off the dinosaurs?

Throughout the 1980s, debate raged over the fate of the dinosaurs. In the meantime, an Arizona astronomer, Gene Shoemaker, became concerned with another question. If most life had been wiped out by an asteroid 65 million years ago, what were the chances that another space rock was on its way for a repeat performance?

Shoemaker, a man who had unlocked the secrets of Meteor Crater, began to lobby whomever he could that astronomers should be watching the sky for the next Earth-collider.

One of the first to take up his challenge was Tom Gehrels, who had already been studying asteroids for their physical properties. In 1989, Gehrels' Kitt Peak program, Spacewatch, developed new software that allowed it to search more efficiently not only for the asteroids out beyond Mars but also those asteroids and comets that came into the Earth's vicinity.

These Near-Earth Objects, or NEOs, can be elusive. Fast-moving and anywhere from the size of a grain of sand to the size of a city, they can be exceedingly dim.

The pebble-size ones are of no real concern. Entering the atmosphere at about 70,000 miles per hour, they burn up from friction. At night, we see them as meteors, or "shooting stars."

But objects larger than a house make astronomers nervous. A building-size object carved out Meteor Crater some 40,000 years ago. The resultant shock wave would have imperiled the people of Flagstaff, 40 miles away, if the town had existed.

Scientists figure that the entire globe would be in trouble if hit by an object about a kilometer across or larger. Even people and animals far from the impact and not killed by a tsunami or rain of ejecta would eventually feel its effects. In the case of the dinosaur-killer 65 million years ago, scientists theorize that a large impact, perhaps with an object seven kilometers across that is believed to have struck near what today is the Yucatan Peninsula, threw so much of the Earth's crust into the atmosphere that the entire planet was veiled in an opaque layer of grime. Pitch-dark at the surface for months, most plant life would have died. For years, the planet would have been gripped in a nuclear winter.

What are the chances that such a cataclysmic impact will occur in a human being's rather short lifetime?

About one in 5,000, says Tom Gehrels.
Gehrels estimates that a one-kilometer-size object hits the Earth about once every 330,000 years. Divide that by the typical lifetime of 66 years, and you get the 1 in 5,000 result.

Those are the same odds that a person will be killed in an auto accident.
Despite those odds, and Spacewatch's increasing ability after 1989 to find such potentially hazardous objects, scientists still had trouble convincing the public that it was in danger.

In particular, astronomers had trouble convincing Congress, which refused NASA requests for funding of Spacewatch and other projects searching for NEOs.

Then, in 1994, Congress and the rest of the world got a preview of things to come. Fragments of Comet Shoemaker-Levy 9 plowed into the planet Jupiter that July and created devastation on Earth-size scales. One of its discoverers was the same Gene Shoemaker who had years earlier begun telling scientists to watch out for just such a cataclysm. (Shoemaker himself met an untimely end in a collision of another kind. He was killed in an automobile accident in 1997 while on a trip to Australia to inspect impact craters.)

After Shoemaker-Levy 9's amazing show, a duly impressed Congress approached NASA and ordered that the country's scientists get to work. Within 20 years, Congress mandated, astronomers should find and plot the orbits of 90 percent of the objects in the solar system with the potential to collide with Earth.

Astronomer Brian Skiff says that's when Flagstaff's Lowell Observatory decided to jump into the game.

With new NASA funding available, Skiff says, Lowell scientists realized that Spacewatch could be beat in the search for NEOs.

Astronomers face a dilemma when they're looking for "Earth-crossers" (what astronomers call objects that cross Earth's orbit and could someday hit us). Do they look deeply at a small piece of sky, or more superficially at a larger swath? The first method picks up smaller objects that have a greater chance of hitting us; the second method picks up more total objects, but misses the smaller ones.

Spacewatch had settled on the first approach, going deep on small pieces of sky. Lowell decided to develop a telescope that would see more of the sky and forsake the small objects to go for the big rocks with the potential of wiping out all life.

Since 1994, Skiff says, Lowell has struggled to develop its LONEOS system, for Lowell Observatory Near-Earth Object Search, which finally came online and found its first NEO last summer. But the two Arizona projects complemented each other well and led the other handful of NASA-funded programs in the search for potentially hazardous objects. Between Spacewatch's deep search for small objects and LONEOS's wide view looking for planet-killers, Arizona had become the place most responsible for alerting planet Earth. Both programs became swamped with media requests as reporters and film crews, particularly from Europe, clamored to interview the scientists searching for Doomsday.

Those requests haven't slowed.
Then, last year, strange rumors began.

By last fall, the buzz in asteroid circles concerned a new program no one seemed to know much about.

Asteroid hunters spoke of a project working out of a restricted military base that was all but usurping their field. Its rumored attributes made astronomers in Arizona sound like a bunch of conspiracy theorists:

Secret "black" technology being used by the military to hunt down asteroids by the thousands . . . superfast imaging cameras capable of things unimaginable to other astronomers . . . discoveries of Near Earth Asteroids, main belt asteroids, and comets on a staggering scale, leaving precious little undiscovered for projects like Spacewatch.

That's when New Times began a long process of getting access to something called LINEAR, for Lincoln Near-Earth Asteroid Research. The people who run it, at MIT's Lincoln Laboratory, tried to discourage a visit; Grant Stokes, who runs the program from Boston, hoped that a visit to his offices there would prove satisfactory. But he was pressed to arrange a visit to the installation itself, which is on the White Sands Missile Range near Socorro, New Mexico.

Two months and three layers of government approval later, Lincoln Lab agreed to a visit.

After a six-hour drive from Phoenix, the road to LINEAR terminates at the north entrance of the missile range, just a mile from Trinity Site, where the first atomic bomb exploded July 16, 1945.

While visitors are interrogated by a humorless guard, they are greeted by a sign.

WARNING
(then, in disconcertingly small type)
"You are entering an active explosives test range. Areas are potentially contaminated with explosive devices. Stay on the roads. Do not touch or disturb any items. If items are found call the White Sands police . . ."

Just a few hundred yards away across a high desert landscape (which, according to the warning, sounded like it concealed a lethal minefield of unexploded cruise missiles) lay the LINEAR observatory, a squat sheet metal building with various small observatory domes surrounding it.

LINEAR operates out of just one of the domes, and the Air Force uses the rest in a program called Ground-based Electro-Optical Deep Space Surveillance, or GEODSS, a typically unpronounceable military acronym for a program that keeps track of the 9,500 manmade objects circling Earth. From errant astronaut gloves to foreign spy satellites, GEODSS keeps the Air Force in the know about everything whizzing over American airspace. The technology to track manmade objects, it turns out, is equally effective at detecting celestial ones.

Three men waited to give a tour of the building. Grant Stokes had flown in from Boston, Eric Pearce was the on-site astronomer who managed the facility, and Roger Sudbury was a Lincoln Laboratory public relations man whose main job seemed to be to follow the other two around nervously to make sure they didn't say something they shouldn't.

Stokes, in contrast, was friendly, intelligent, and positively beaming. And he had every reason to be. His program in just a few months has revolutionized the field of asteroid detection.

He led the group to a conference room to talk about how his project--using a telescope just slightly bigger than Gehrels' on Kitt Peak--had leapfrogged past all the others. On the way, he passed a notice pinned to a bulletin board in the hallway:

Technology Protection
"To maintain our lead, secrecy is essential. The intelligence threat to the U.S. has not disappeared. Even some of our allies have organized intelligence operations dedicated to acquiring U.S. technology. Technology protection is the best countermeasure. Let's all do our part to prevent future leaks."

Stokes, however, seemed happy to give up LINEAR's secrets. He opened up a black plastic case and showed off the mysterious equipment that astronomers had been spreading rumors about. It was a single, four-inch silicon wafer, the sort manufacturers like Intel carve up into small chips for computers. But this wafer was different.

The entire thing was just one chip.
It was the LINEAR charge-coupled device or CCD, the heart of a camera that rides on a telescope. Like a proud owner talking about the cool equipment on his cherry show car, Stokes pointed out the features of his souped-up machine.

A CCD chip is a computer's eye on the world. Small CCD chips power camcorders and digital cameras; their sensitive electronics record an image on picture elements (commonly called "pixels") that are then read into a computer. Camcorder CCDs make do with a few hundred thousand pixels; the LINEAR chip has five million.

Like other CCDs used in observatories around the world, the LINEAR chip is especially sensitive and can soak up starlight quickly. But LINEAR leaves those other chips in the dust when it comes time to download its image into Air Force computers.

After soaking up an image of starry sky, other astronomers have to close a shutter and can wait up to two minutes for the image to read out of a large CCD, column by pixel column.

The LINEAR CCD, by contrast, downloads its five million pixels in a few milliseconds.

While astronomers in Arizona methodically patrol smaller swaths of sky, the LINEAR chip pops off thousands of exposures each night mounted on a telescope built for speed.

Pearce showed off the project's one-meter telescope housed in a small dome outside the LINEAR shack. He goes out to the scope each working evening to take off a cloth cover, but unlike Gehrels at Spacewatch, the rest of the night Pearce stays inside the heated building as the scope runs completely on its own. There's no need to watch the scope for fear that it might run into something.

Taking rapid snapshots in a stairstep pattern, the LINEAR scope covers so much sky in a single night, it has time to go back and image previous areas five separate times.

Then, inside the control room, Frank Shelly and his software take over. Shelly demonstrated how the five separate images of a piece of sky are layered on top of each other by powerful computers. With the push of a button, the software seems to gobble up the images in a pulsing display that devoured the thousands of stars on the screen. Suddenly, the only thing showing are the handful of objects the computer had decided were asteroids. Everything else had been subtracted.

Even in a field taken in the Milky Way--where other astronomers fear to tread because of the dense concentration of stars--the LINEAR computers gobbled up the fixed stars and found asteroids hiding amid them.

"If you're willing to take five frames, the software has a very good performance with respect to probability of discovery and a very low false-alarm rate," said Stokes in his typically understated, technical way. "The Minor Planet Center tells us that when we sweep through an area we find everything we're supposed to find. Everything they know about we find and plus all the other stuff they don't know about."

The results have been astonishing.
Since LINEAR went online at full speed last March, the project has swamped the Minor Planet Center--the world's clearinghouse of asteroid information at Harvard University--with new discoveries.

Of the 147 total Near-Earth Objects found in all observatories between March and November, LINEAR discovered 102.

Of those one kilometer and larger--the size considered large enough to cause mass extinctions in an impact with Earth--LINEAR discovered 26 of the 38 total.

Out of 28 comets discovered in the same period, LINEAR had its name attached to 13.

Before last March, the Minor Planet Center had received about 10,000 observations every month from scientists all over the world. In September 1998, a particularly clear month in New Mexico, LINEAR alone sent the MPC more than 160,000 observations.

By January, overworked orbit calculators at the Minor Planet Center had given designations to 19,200 new asteroids discovered by LINEAR in only 10 months of operation.

Spacewatch, by contrast, has 25,000 new asteroids to its name. But that's after 10 years of full-blown operation.

Harvard's Minor Planet Center "is going to have to get some new computers," Stokes says with a satisfied grin.

Stokes has reason to be smug. Two years ago, he says, he began visiting astronomical conferences to tell others about the LINEAR concept, and he was surprised at the response.

"It was met, I think, with an awful lot of skepticism as to whether we could really pull it off," he says. "I think now that we're up and running hard, where we're scooping up enough in the sky all by ourselves, at some point I believe we will want to, you know, coordinate searches between the astronomers. We're looking at figuring out ways to do that. That's clearly in the future."

Did he mean the LINEAR people would give others access to that expensive Air Force technology?

"I think there are a lot of people who would like to get that chip," he said with another grin.

Asked what the chip had cost to develop, Stokes said it would be difficult to isolate. He and other scientists at Lincoln Laboratory had produced the chip as they sought ways to help the Air Force with projects such as Space-Based Space Surveillance--in other words, satellites spying on satellites. It's Stokes' main gig, one he got after studying for a doctorate in physics at Princeton, where he hunted for pulsars--degenerate stars spinning at incredible speeds--with a radio telescope. After grad school, Stokes says he got away from astronomy and dove into the field of surveillance.

Eventually, he says, it dawned on him that the surveillance equipment they were developing at Lincoln Laboratory could be used to find near-earth asteroids. The Air Force accepted the LINEAR proposal and has spent about a million dollars in the past three years to make the project a reality, Stokes says.

Stokes won't say what the souped-up chip cost to develop, but one non-LINEAR astronomer tells New Times he believes the Air Force spent between $150 million and $200 million to build it. That's in comparison to projects like Lowell's LONEOS, which hasn't spent a million dollars in its entire history.

Lowell's Brian Skiff scoffs at the estimate and says he doesn't think the military spent that much.

But Skiff does acknowledge the superiority of the Air Force technology.
"In five years, LINEAR will have everything in the solar system mapped down to the crumbs," he says enviously.

Arizona asteroid hunters had hoped they might save Earth from extinction by asteroid. Now they're scrambling to save themselves from extinction by LINEAR.

Tom Gehrels was asked what he thought about the impact of LINEAR, and he answered only by saying that LINEAR's contribution was welcome.

But Lowell's Brian Skiff in particular wonders what's the point of trying to compete with the military's amazing program.

"I thought I did really well last night," he says, sounding dejected. "I detected 900 asteroids at the opposition point [the portion of sky opposite the Sun]. LINEAR no doubt was there three nights ago and saw 9,000 objects."

Skiff says LONEOS now has to look forward to a short period when the monsoon season leaves Arizona and lingers in New Mexico, keeping LINEAR's observations low. "We're occasionally picking up things that slip through their net, and ultimately the science gets done, whether by us or somebody else. Then again, it's a bit disheartening to struggle for several years to get a project rolling, only to have somebody come along in a balloon and usurp your work because of a tremendous technical advantage."

Skiff says that Lowell will be getting new equipment, however, and he's heard that the Air Force will begin looking deeper into space.

"If LINEAR goes deeper, they'll cover less sky. With a new camera, we'll cover more sky and the projects will become more complementary. So it's not totally hopeless," he says.

Both Spacewatch and LONEOS astronomers emphasize that they do more than just look for asteroids heading for a doomsday with Earth. Spacewatch has always been as interested in the physical characteristics of the asteroids themselves and describing asteroid families. LONEOS, meanwhile, contributes to a University of Washington program to track down undiscovered variable stars.

But those projects aren't what bring journalists in flocks to Kitt Peak and Lowell Observatory. The glory is in discovering hazardous objects. And increasingly, LINEAR has all but taken over that role.

Robert McMillan, Spacewatch's principal investigator, downplays the impact LINEAR has had on his team. "We're really a scientific investigation. We're not just looking for things that threaten the Earth, but we're trying to figure out distribution of the asteroids and their characteristics. Spacewatch is a much more comprehensive scientific investigation. As long as they [LINEAR] don't pretend to be scientists, I have no problem with it at all. They're obviously doing it better than the other groups. But maybe not for long," he says.

It's hard not to perceive some resentment in the way Skiff and McMillan describe LINEAR. After all, the Arizona scientists are astronomers who study asteroids as interesting solar system denizens. The LINEAR workers, however, are Air Force tech-heads with fancy electronics who couldn't care less what it is they're actually tracking down.

LINEAR's Grant Stokes doesn't flinch at the description.
"Am I a real astronomer? Maybe," he says. "I think asteroids are quite interesting, but the way we got into this is asteroids as targets, not asteroids as fundamentally interesting. . . . In fact, asteroids were just like everything else; you could make them look like everything else we track. We're getting an education. The astronomers are experts in asteroids and work hard to build systems that find them. We have systems that find them and we're working toward understanding asteroids."

What the LINEAR scientists discover seems less interesting to them than to astronomers such as Spacewatch's Tom Gehrels, who marvels over dim comets that he directs a 79-year-old telescope to view.

Last fall, a comet discovered in LINEAR's massive survey labeled 1998 U5 captured the attention of many astronomers when it suddenly flared in brightness. Amateur astronomers around the country kept their eyes on it. Did the LINEAR scientists follow the progress of their fascinating find?

"Not in any real sense," Stokes answered. "I mean, we certainly try to keep track of the interesting things that we find. We find, quite frankly, so many of them that any individual one you ask me about I'll give you a blank look."

Despite its relative uninterest in what it finds, the LINEAR project now has an awesome responsibility. Given its seizure of the asteroid-detection field, it's likely that the next asteroid to threaten the planet will be found by LINEAR. In other words, it's the Air Force that will tell us about the doomsday rock.

Imagine what Art Bell and the conspiracy crowd will do with that one.
Stokes assures New Times that all of LINEAR's observations are sent directly to the Minor Planet Center. If anything, he says, it will be the MPC that will determine that one of the rocks found by LINEAR is on a collision course with Earth.

"They'll tell us about it, not the other way around," he says.

While Spacewatch and LONEOS hurry to catch up to LINEAR and its awesome chip, NASA has decided to make things even tougher on the Arizona astronomers.

LINEAR recently applied for, and got, NASA funding to add to its Air Force money. What will it do with the added cash?

Start a second LINEAR, says Grant Stokes. It's a fairly simple matter of strapping one of the superchips to another of the facility's telescopes and should be done by this spring, he adds.

Earth gains even more protection, and the other programs fall even farther behind.

Does LINEAR's success threaten the continued funding of other programs by NASA?

"We know that these groups move in and out," says NASA's Tom Morgan. "You really can't predict it. That's why we give them some time. In the fullness of time, they will be due a full proposal, and they will be evaluated by their peers."

Funded in three-year cycles, LONEOS and Spacewatch have some time to produce results before they reapply for NASA money. LONEOS operates entirely on the space agency's funds. Spacewatch, meanwhile, relies on NASA money for about a third of its budget.

James Scotti says Spacewatch is wasting no time. "I think it pushes everybody in the business to do what we had all planned to do anyway. For a while we were the big guys on the block, taking over from the Shoemakers at Palomar."

Scotti became an overnight celebrity when it was announced last year that he had found a mile-wide object that could wipe us out in 30 years.

Scotti's find, XF11, will actually miss Earth in 2028 with plenty of room to spare. But for a day, at least, Scotti seemed to have been the man who had pegged Judgment Day.

Now, after being leapfrogged by the Air Force, Scotti says Spacewatch is determined to catch up to LINEAR. New cameras mounted on Spacewatch's old telescope and the completion of a newer, larger telescope as well as new software should begin bridging the gap between the two systems.

But even if Spacewatch and LONEOS can upgrade their equipment and catch the Air Force techies, isn't there a built-in obsolesence to their searches? Won't they eventually know the location, speed and direction of every one-kilometer space boulder with a chance of hitting Earth?

"We'll certainly solve the problem at some point. But what about the half-kilometer objects? One of those could kill millions. It all depends on how far down you want to draw the line of what's dangerous," Scotti says. "You're trying to put a complete picture of what the solar system looks like. And it's difficult, particularly when you go into the outer solar system where these things are so faint. Even all of the surveys we have in mind are not going to find these very small objects."

There's a good possibility that after several more years of searching--and several million dollars spent--astronomers will find that Earth is not likely to be hit by a significant impact for centuries or even thousands of years. Along with a global sense of relief, will asteroid hunters experience a sense of frustration? Would mass death vindicate someone like Tom Gehrels, who has worked for so many years to make the planet take the asteroid threat seriously?

"There was a wish," Gehrels says, "during the Cold War." Asked to elaborate, Gehrels admits that he had yearned at one time that a menacing asteroid might be found, hoping that it would force nations to cooperate and avert disaster.

In the meantime, until LINEAR steals it away, press attention seems as everpresent in Gehrels' life. He admits that it's been "maybe a bit of each, a little annoying, a little satisfying."

If he found reporters to be more trouble than they were worth, however, Gehrels was only getting the attention that he richly deserved.

It seemed a shame he was finally getting that attention just as he was being made obsolete.

Contact Tony Ortega at his online address: [email protected]

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