-
- The asteroid that astronomers first said in March last
year may strike Earth in 40 years would have initially rated a 1 on a new
0-to-10 scale of impact risks.
-
- The "Torino Scale," developed by Massachusetts
Institute of Technology astronomer Richard Binzel, was unveiled Thursday
by the International Astronomical Union, according to The Boston Globe.
-
- The scale was first presented last month at an astronomers'
meeting on the risk of impacts from comets or asteroids held in Torino,
Italy, where it was endorsed by astronomers, the Globe reports.
-
- Binzel and other astronomers think many people were unduly
and unnecessarily alarmed by some of the initial media reports of the possibility
of an impact with that asteroid.
-
- Despite the initial fright, on the new scale, asteroid
1997 XF 11 would have quickly been found to have a true risk of zero.
-
- "What I hope the scale will accomplish is to put
in perspective whether an object merits concern," Binzel says.
-
- Binzel and others liken the new scale to the Richter
scale, used for measuring the intensity of earthquakes. But the Torino
scale is actually quite different. While those scales measure intensity,
the asteroid scale attempts to combine both the severity of an impact and
the probability of its occurrence, the Globe says.
-
- For example, an object about the size of a house or smaller
would be rated zero, even if it were certain to strike, because it wouldn't
hurt anything. But an object headed for Earth that was, say, between 60
and 300 feet across would have a rating of 8, because such an impact could
devastate a city-size region.
-
- Objects larger than 3,000 feet across -- big enough to
threaten the entire planet -- would get the highest rating of 10.
-
- While praising the scale in general, Benny Peiser, an
anthropologist at Liverpool John Moore University in England who circulates
a daily newsletter of information about the hazards from asteroids and
comets, tells the Globe, "As we've seen in the last 12 months, things
change so rapidly and so unexpectedly that we might see some limitations
of the scale."
|
