Just kidding. Asteroid 2005 YU55 is projected to pass tomorrow within the Moon's orbit, about 200,000 miles out. That's pretty close, but too far to do any harm.This asteroid is about as big as an aircraft carrier. If it hit, it might result in a 4,000-megaton blast, a 7.0 earthquake, and (if it struck water) 70-foot-high tsunamis in the very immediate vicinity. An impact of that kind is estimated to be about a 100,000-year event. In contrast, the 65-million-year-old K-T boundary "dinosaur killer" probably was 5 or 10 miles wide, and that is considered about a 100-million-year event.
One of my favorite scifi stories is "Lucifer's Hammer," a TEOTWAWKI fantasy about a comet strike.
Asteroid guru Jay Melosh of Perdue University adds that "Apophis, a similar-sized asteroid about one-third of a mile in diameter, is the biggest threat in our near future. It has a tiny chance of striking the Earth in 2036." Yeah, that's what they said in Lucifer's Hammer. It's always a tiny chance until it happens! Nevertheless, although an object of that size might wipe out a big city, it probably wouldn't lead to any extinctions.
...and that is considered about a 100-million-year event.
ReplyDeleteNot that we have anything like the historical perspective that would make such a claim valid. That's one of those claims of the type that "Black Swans" author Taleb normally mocks, and with very good reason.
It's a rough estimate based on geological evidence of prior strikes of that size. It may not be an extremely reliable number, but it's not a meaningless one.
ReplyDeleteDang! Missed again....
ReplyDeleteThis is a probability assessment, as T99 notes. We could have two events today, or none for a billion years. What is noted is likelyhood, not strict determinism.
ReplyDeleteGreat article.
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