Is an asteroid scheduled to hit Earth in 2012?
An Internet search for "2012 doomsday predictions" will return enough apocalyptic prophecies to send you screaming into an underground bunker. Such ominous forecasts are based on the dubious assertion that, according to the Mayan calendar, the end of the world is scheduled to occur on Dec. 21, 2012. Those who adhere to this notion don't agree on how it will happen, but a common theory is that an asteroid will hit Earth, throwing up a cloud of choking dust that will block the sun and catastrophically alter the planet's climate. So, will a flaming mass of rock tear through the sky in 2012, bringing an end to civilization as we know it? In short, no.
Asteroids are masses of metal and rock that orbit the sun but aren't large enough to be considered planets. Tens of thousands of them are located in the asteroid belt, a doughnut-shaped ring between the orbits of Mars and Jupiter. Most doomsday prophecies focus on near-Earth asteroids (NEAs), or asteroids whose orbits bring them within 121 million miles (195 million kilometers) of the sun and, as the name suggests, sometimes pass relatively close to Earth or even pass through Earth's orbit [source: NASA]. One such asteroid that has gained attention in conjunction with the 2012 scare is Toutatis, a fairly large NEA that measures approximately 3 miles (4.6 kilometers) long. On Sept. 29, 2004, Toutatis made its closest approach of this century, missing Earth by just 962,951 miles (1,549,719 kilometers) [source: NASA]. It's expected to pass close to Earth again on Dec. 28, 2012, a week after the supposed apocalypse date, though at the greater distance of 4.3 million miles (6.9 million kilometers) [source: Minor Planet Center]. Though some Web sites may claim otherwise, neither Toutatis nor any other asteroid of any significant size is expected to hit this planet in 2012.
Are we in danger of asteroid strikes in the future, and if so, can we do anything to stop them? Click over to the next page to find out.
The Asteroid Threat
Although we're in the clear for 2012, that doesn't mean that asteroids aren't a threat. Scientists blame the impact of an asteroid or comet measuring some 6 miles (10 kilometers) across for the extinction of the dinosaurs 65 million years ago. More recently, on June 30, 1908, an asteroid measuring 330 feet (100 meters) in diameter struck Siberia, flattening half a million acres of forest. There've been some breathtaking close calls as well. On March 23, 1989, scientists were surprised when a quarter-mile-wide (0.4-kilometer) asteroid weighing 50 million tons missed Earth by just 400,000 miles (640,000 kilometers). Amazingly, Earth and the asteroid had occupied the same point in space just six hours apart [source: NASA].
Because of asteroids' deadly potential, several organizations are actively working to locate large near-Earth asteroids (NEAs) before they hit Earth, including the University of Arizona's Spacewatch Project, and NASA's Near Earth Asteroid Tracking Team and Asteroid and Comet Impact Hazard Group. One threat they're currently tracking is Apophis, an asteroid measuring 690 to 1080 feet (210 to 330 meters) wide, which is scheduled to make a historically close approach to Earth on April 13, 2029. That day, scientists predict that the asteroid will miss this planet by as few as 18,300 miles (30,000 kilometers). When it approaches again in 2036, there is a very small probability -- just 1 in 250,000 -- that it will strike Earth [source: Brown and Agle]. In the off chance that this did occur, it could badly damage an area the size of France or Germany, but would not cause worldwide destruction.
Thanks to the agencies that scan the sky for NEAs, scientists will have plenty of warning if an asteroid like Apophis is on a crash course with Earth, and they can take action to deflect it. This would involve launching a spacecraft to intercept the asteroid and nudge it from its trajectory using chemical rockets or a large electromagnetic accelerator known as a mass driver. For the time being, however, scientists insist there's nothing to worry about; no known asteroids are on a collision course with Earth in 2012 or at any time in the near future.