by Michael Mackowski
Outer space may literally be mostly empty space, but our solar system is full of large and small chunks of rocks. A few days ago, a couple of these rocks made a close pass to our home planet. One object, called asteroid DA14, was large enough to be detected about a year ago. It came within 17,200 miles of the Earth’s surface, within the ring of geostationary communications satellites we all rely on. There was enough information on this object to know in advance that it would come close, but miss us. Still, this asteroid was the closest large object to pass by the Earth that we saw ahead of time.
Meanwhile a smaller object, perhaps the size of a school bus, whizzed over Russia, and when it exploded several miles above the ground, the shock wave was strong enough to smash windows over a large area, injuring over a thousand people from flying glass. This object was too small to be detected in advance, at least with the technology we are using today.