The scientists were practically laughed at on television by the science minister of Australia who, like much of the world's public, simply does not take the threat of asteroids seriously.
The reason is simple: The Dread Factor is not high enough.
Paul Slovic, author of "The Perception of Risk" (Earthscan, 2000), says most people are far more worried over what humans and technology can do to them than they are about natural disasters. While terrorism, chemical spills and nuclear accidents are awarded high "Dread Factor" marks by most people, asteroids, earthquakes and hurricanes rate low.
Stealth approach
On March 8, a hunk of stone and metal about the size of an 18-story building, made its closest approach to Earth, passing roughly 298,400 miles (480,200 kilometers) from the planet, just a bit farther out than the Moon, but a little too close for comfort for most astronomers.
But what was most disturbing was that the asteroid, later named
, passed virtually unseen. Not until March 12, when it had moved out of the glare of the Sun and into the night sky was it seen from Earth.And it was not alone: On Jan. 7, an asteroid the size of three football fields came within two lunar distances and was spotted only a month before. Last October, a smaller asteroid passed by at a similar distance and was detected just two days prior.
For each nearby asteroid that is spotted, several pass entirely unnoticed, some closer to us than the Moon, scientists say. One researcher estimates that each year, 25 asteroids roughly as large as 2002 EM7 whiz by at even closer distances.
They slip through because of limitations to technology, telescope time, and funding.
These close brushes illustrate a message that asteroid researchers have repeatedly tried to hammer home to politicians and the public: The number of undiscovered asteroids far exceeds the known list, and the list needs to be filled out before it's too late.
Asteroid 2002 EM7 left a a pretty ominous message on its own: Only a tremendously expensive new telescopes -- placed outside Earth's orbit so as to monitor the blind spot created by the Sun -- could guarantee we won't suffer an unexpected and sudden impact. There would be a flash of brilliant light in the sky, and seconds later the world would change forever in a way that would render Sept. 11 an insignificant memory.
Dread Factor vs. reality of risk
Scientists develop asteroid risk statistics by estimating the total number of objects that exist and by studying evidence of past encounters -- big holes in the ground called impact craters.
From these clues, they say your chances of death by asteroid are about the same as dying in a plane crash, roughly 1-in-20,000 during your lifetime. You're more liable to be electrocuted to death (1-in-5000 chance), succumb to skin cancer or be killed in a car crash.
Yet asteroids pose more risk than tornadoes (1-in-60,000 chance), rattlesnake bites or food poisoning.
If Earth is hit, you could die by direct impact and vaporization. Or you might be killed in an associated earthquake or volcanic eruption as the planet's bell is rung like never before in recorded history. Or perhaps like countless lesser species, you'll die a slow, agonizing death of starvation as the world's food supply dwindles in the face of reduced sunlight caused by a global debris cloud.
Yet if you're like most people, you are not all that worried, according to sociologists and psychiatrists who study these things.
Slovic, the author, also works at Decision Research, an organization in Oregon that advises industry and government about risk. He says we do not base our fears on statistics. Instead, each of us develops our own personal Dread Factor for various frightening scenarios based on personal experience, knowledge and, more important, our sense of the situation.
Emotion has replaced instinct as a major risk-assessment tool for modern humans, who face myriad dangers, none of which involve sneaking up on woolly mammoths from behind a tree.
"It is more of a gut feeling," Slovic says. "Does it worry me? Does it scare me? Does it make me uneasy?"
Cars are low on most individuals' Dread Factor lists, even though the average American stands about a 1-in-100 or 1-in-200 chance of dying in an automobile.
"We don't dread cars," Slovic says. "Things that cause cancer are high on the Dread Factor."
Scientists vs. voters
The Dread Factor, or lack of it, can drive political funding decisions.
The U.S. Congress apparently perceived the threat real enough to require NASA to make asteroid hunting a serious business. The space agency spends $3.55 million each year searching for and studying asteroids. (Much of that money goes to space-based research of asteroids that pose no threat.)
Individual search programs provide much of their own institutional funding. And amateur astronomers around the globe contribute to the effort. Not everyone, however, sees an urgent need.
The Australian Science Minister Peter McGauran, appearing on his country's 60 Minutes television program March 17, called the effort to find potentially threatening asteroids "fruitless, unnecessary, self-indulgent" and promised no funds unless researchers provide a more convincing argument for the need.
To the consternation of many researchers, there are no telescopes below the equator devoted to searching southern skies for asteroids. Australia cut funding to one such effort in 1996.
An ongoing online poll taken in conjunction with the televised program found overwhelming support -- 91 percent at last count -- for reinstatement of the funding. But these votes were cast by people who watched an animated asteroid slam into Earth and listened to leading experts spout frightening statistics and detail the grim outcomes they say are only a matter of time.
You and most other voters, in Australia and around the world, probably lean more toward McGauran's sentiment. According to experts in risk assessment and fear management, McGauran's starkest statement likely reflects the general public mood: "I lie awake worrying about a lot of other things. Near-miss asteroids is not one of them."
The average person tends to be much more afraid of industrial accidents, for example.
As with terrorism, vast sums of money are spent, as Slovic puts it, "to take small risks of chemical and radioactive pollution and reduce them even further. We spend a huge amount for every statistical life saved. On the other hand, if you wanted to get people to spend money on asteroid protection or earthquake mitigation, it's very difficult, even though the risk is much greater."
Richard Taylor of the Probability Research Group, a global affiliation of researchers looking into various science topics, thinks there is a clear message in the fact that nations spend billions on military defense but zero scanning our entire Southern Hemisphere flank for asteroids:
"We feel more at danger from man than from Nature," Taylor says.
Next Page: Why we don't care
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