This isn't going to happen on Friday, February 15, 2013. via
Unfortunately for doomsdayers, the world isn’t going to end this week when an asteroid come close to the Earth. But it is going to be one hell of a close shave, coming within 17,000 miles of the planet’s surface.
The asteroid in question is called 2012 DA14, and was discovered by a small team of astronomers at the La Sagra Observatory in Southern Spain on February 22, 2012. They found it using a specialized camera on one of the observatory's telescopes that’s designed to detect really fast moving objects. And because it's coming near Earth, the asteroid has been a huge source of interest for researchers.
2012 DA14 isn’t huge, about half the size of a football field and a little more than 147 feet in diameter. Astronomers figured out its trajectory, and concluded that there’s no chance the asteroid will end up hitting the Earth. But the predicted 17,000 mile pass is close, closer than some geosynchronous satellites, which typically orbit about 22,245 miles above the equator and support such important things as out communications network. (Thankfully, astronomers have ruled out the possibility of the asteroid taking out a satellite; these satellites actually have a higher likelihood of hitting each other than being hit by an asteroid.)
2012 DA14's trajectory as it skims the Earth. Looks kinda freaky from here. via
But what would happen if 2012 DA14 did hit the Earth? The asteroid may be small, but it would pack a punch. The energy of this asteroid hitting the Earth would be more than 100 times the energy of the nuclear bomb that fell on Hiroshima, easily taking out any major metropolitan city on the planet with a direct hit. It would be comparable to the Tunguska impact of 1908. An asteroid entered the Earth’s atmosphere over Siberia, and while it didn’t hit, it’s thought to have broken up during its descent. The resulting shockwave from the air burst was powerful enough to level nearly 1,500 square miles of Siberian forest.
When it does come to Earth on Friday, 2012 DA14 will move pretty quickly from the southern evening sky into the northern morning sky. But it will be hard to spot, just dim enough that you’ll need binoculars or a small telescope to see it. After this first pass it will cross into the Earth’s shadow for about 18 minutes before reemerging only to fade entirely from view as it streaks towards the bright northern morning sky.
Leveled trees in the aftermath of the Tunguska event, as seen in 1927. via
This asteroid won’t hit the Earth this time, but it is orbiting the Sun and will come back around. Decades from now, we could be on a collision course. It’s a sobering reminder that there are all kinds of things out there trying to kill us, and not just cylons or mutant aliens. Tracking asteroids is a worthwhile cause, one that might save us in the future. It’s not a questions of if an asteroid will threaten life on our planet, it’s when. But hey, at least we're safe for now.