| A 1 on the Catastrophe Scale |
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A dry run for the brand-new Torino impact scale
In 1999, a group of specialists created an official scale for cosmic impact risk, called the Torino Scale. An ordinary comet appearing in the sky is rated zero—good for a show. A huge asteroid bearing straight down on us is rated ten—total death, kiss your ass goodbye. When I first heard about the scale, I hoped I would never see it used. When I first wrote about the scale I said, "The next stage is figuring out what to do once a real Torino Scale warning comes out. That should be very interesting."
Less than a year later, we found out. The International Astronomical Union issued a notice about a small, bright object in space that was discovered in late September 2000. The IAU's early calculations of its orbit suggest that when it comes around in the year 2030, it might get pretty close to Earth.
The object is named 2000 SG344 and seems to be about the size of a mansion, give or take a wing. If it's on the small side of its size range, then its Torino scale rating is zero. But if it's large, the rating goes up to a 1. That means that we should keep a close eye on it, but nevertheless the risk of it striking Earth is no worse than the average risk of a collision in any given year.
What would a collision be like? We have a pretty good idea of that from history. Specifically, a house-size asteroid struck backwoods Siberia in June 1908, and the results were worse than any explosion we had ever created at the time. Today, unfortunately, we can say the effects were the same as those of a fair-to-middling nuclear bomb. It could demolish a large city and its suburbs. If it hit the sea, a dangerous tsunami would affect the region. Something like that is well worth watching out for.
The IAU has given us the gentlest possible warning: "In line with its policy decisions, the IAU does not intend to make any further statements on the eventuality of an impact by 2000 SG344, leaving that to the individual scientists who are observing this interesting small asteroid and computing its orbit." So consider this a dry run of the warning system. Someday, maybe centuries from today, it might save our lives.
