The first sentence of the article is incorrect - this isn't the closest known approach of a space rock to the Earth. Besides the obvious examples like the Meteor Crater of the ones that actually impacted, there was a pretty big rock (estimated size from 80 feet to 80 meters in diameter) that was filmed in 1970 as it actually entered the Earth's atmosphere. It was estimated to be somewhere around 30 miles high and flying roughly parallel to the Earth's surface. It entered the atmosphere in the US southwest and exited somewhere around Canada. That's close!

Still, 26,500 miles is pretty damned close, too. That's only a few thousand miles beyond geosynch satellites, about 1/8th the distance from the Earth to the moon. In astronomical terms, that's damned close!

Interesting from a timing perspective, some of my coworkers and I just yesterday finished a demo operational architecture called the Earth Defense Model using our object-oriented technique. We're going to be giving it out at the Space Symposium held at the Broadmoor Hotel later this month. The model covers detecting and cataloging Earth threatening objects, performing high resolution path prediction and impact prediction, as well as the work required to determine if a response is possible and what it should be.