Meteorite Explodes; Asteroid Passes By Harmlessly

It has been a busy day in space news today! Earth and its satellites were closely passed by the 45-metre Asteroid 2012 DA14 today, coming within 27,600 kilometres of Earth, making it the closest flyby of a rock of its size. Coincidentally, a ten-ton meteorite exploded above Russia’s Ural Mountains just hours before the asteroid flew past the planet.

NASA and other scientists have said that the meteorite and the asteroid incidents are unrelated, as they both seemed to be travelling in different directions. In size comparison, the meteorite over the Ural Mountains was approximately 10 metric tons, while Asteroid 2012 DA14 was 143,000 tons.

Citizens of Chelyabinsk were heading to work when they saw what is described as “headlights” or a “blinding light” and then felt a shock wave that blew out windows, set off car alarms, and caused hundreds of injuries, mostly from flying glass. Currently about 1,100 injuries have been reported with 43 individuals taken to hospital. The meteorite, possibly made of iron, entered the Earth’s atmosphere and broke apart between 30 and 50 kilometres above ground and was travelling at about 30 kilometres a second. The energy it released once it entered the Earth’s atmosphere was equivalent to a couple kilotonnes, Russia Academy of Sciences said, the power of a small atomic weapon exploding. Local police described how one piece hit the ground by Lake Chebarkul that created a 26-foot crater.

“While events this big are rare, an impact that could cause damage and death could happen every century or so. Unfortunately there is absolutely nothing we can do to stop impacts.”
– Simon Goodwin; astrophysics expert from Britain’s University of Sheffield

Asteroid 2012 DA14, meanwhile, passed by harmlessly and offered quite a show to astronomers in Australia who had a clear night sky. This isn’t the last that we have seen of DA14 though; it is set to return in 33 years according to NASA, on February 15th, 2046 for another flyby, though it will come no closer than 1 million kilometres on the next trip.

If Asteroid 2012 DA14 had broken into the Earth’s atmosphere as the meteorite did, the energy released would be equivalent to 2.4 million tons of TNT and would wipe out approximately 750 square miles. The meteorite in comparison was only one third of the asteroids size.

Diagram of Asteroid 2012 DA14 passing Earth on February 15 2013.