Only recently have researchers glimpsed the dangers lurking in our deceptively quiet neighborhood. Their derision left the field of asteroid hunting largely to amateurs and eccentrics. Even professional astronomers have long dismissed asteroids as undistinguished flotsam and jetsam, would-be planets that circle the sun endlessly in a belt between Mars and Jupiter. We can either close our eyes as we cross the street and not know what we’ve dodged, or we can open our eyes and act accordingly.”Īmid fears about global warming, terrorism, disease, and nuclear proliferation, the threat of rocks from space may seem more the province of bad Hollywood movies than front-page news. “We’ve evolved to the point where we can do something about this threat. “We’re living in a shooting gallery,” he warns. The European Space Agency is contemplating a mission to test ways to push such an object off a threatening trajectory, the first serious attempt at developing a planetary defense.īut a group of astronauts, led by Schweickart, also wants their respective countries and the United Nations to prepare for avoiding a hit. At the request of lawmakers, scientists are struggling to pinpoint 90 percent of all seriously life-threatening asteroids by 2020 in order to assure at least some warning. Fast-paced observations allowed them to calculate a more exact orbital path, which took it far from Earth.Īfter a number of false starts, such potential close calls have finally caught the attention of the U.S. For a brief time in 2004, just months before the Apophis scare, astronomers feared that a 150-foot-wide asteroid was just days away from racing into the atmosphere. Planetary scientists now estimate that 150-foot-wide space rocks, comparable to the one that hit Tunguska, strike only once every thousand years or so. Smaller asteroids are less deadly but much more common. Fortunately, the odds that it will hit are essentially zero. A monster rock discovered just this year, with the prosaic name of 2007PA8, is more than two miles across, large enough to wipe out most of humanity. None are known to pose an immediate threat, but some are bona fide civilization stompers. Slamming into the ocean, Apophis could create a tsunami dwarfing the one that killed more than 200,000 people around Indonesia.Īpophis is one of millions of asteroids roaming the solar system. “If it hit London, there would be no London,” says Apollo 9 astronaut Rusty Schweickart, who had closely followed the discussion of the potential 2029 impact. Then it would either explode just aboveground-as one most likely did in 1908, leveling a vast forest in the Tunguska region of Siberia-or gouge a crater 20 times its size. Traveling at 28,000 miles per hour, it would heat up as it passed through Earth’s atmosphere, turning the dark rock into a fiery sun as it arced across the sky. ![]() Though too small to end civilization-unlike the asteroid that may have doomed the dinosaurs -Apophis could pack a punch comparable to a large nuclear weapon. But that tense day, December 26, 2004, stunned the small group of astronomers who dutifully detect and plot trajectories of hundreds of thousands of the millions of chunks of rock whizzing around the solar system. And April 13, 2036, it will return-this time with a 1-in-45,000 chance of hitting somewhere on a line stretching from the Pacific Ocean near California to Central America.īecause Apophis was discovered during one of the world’s greatest natural disasters, the worries about the impact went largely unnoticed. Nonetheless, in 2029 the asteroid, dubbed Apophis-derived from the Egyptian god Apep, the destroyer who dwells in eternal darkness-will zoom closer to Earth than the world’s communications satellites do. “This was absolutely extraordinary-I didn’t expect to see anything like it in my career.” By the end of the day on December 27, 2004, to the relief of the observers, archival data turned up trajectory information that rendered the odds of a collision nil. “We usually deal with one chance in a million,” recalls Steven Chesley at NASA’s Jet Propulsion Laboratory in Pasadena, California. Furiously crunching numbers on their computers, the researchers put the odds of impact in the year 2029 at exactly those of hitting the number in a game of roulette: 1 in 37. They had inside intelligence that a chunk of rock and metal, roughly 1,300 feet wide, was hurtling toward a possible collision with the most populated swath of Earth-Europe, India, and Southeast Asia. In 2004, as a massive tsunami roiled through the Indian Ocean killing hundreds of thousands of people, a dozen or so scientists quietly confronted an impending disaster potentially even more lethal.
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