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.