The Torino scale, which indicates the dangers posed by meteors hurling towards the Earth, has been modified to minimize the panic created by phrases used in the explanation of its levels. The Torino scale is a zero to 10 scale, with 10 being complete destruction of the Earth and zero indicating nil danger.
Certain phrases like ‘localized destruction’, ‘regional devastation’, and ‘certain global climatic catastrophe’ have been reworded. “This has been an ongoing effort to try to come up with reasonable ways to communicate discoveries when we find an object that's going to pass close to the Earth,” said Richard Binzel of Massachusetts Institute of Technology (MIT), the body modifying the phrases drafted in 1999 in Torino in Italy by the International Astronomers Union. Donald Yeomans, manager, NASA’s Near Earth Object Program Office, said that the wordings are not ‘meant to be frightening’.
A classic case of an asteroid causing unnecessary panic is that of 2004 MN4, which was said to have a two per cent chance of hitting the Earth on April 13, 2029. Further investigations revealed that the asteroid is likely to miss the Earth, even if only by 24,000 to 40,000 kilometre.
This asteroid was given rated 4 on the Torino scale but was later modified as 1. “With further observation, you always can refine the orbit of an asteroid, and it turns out that every orbit that has been refined has always reduced the risk,” said Dr James Biggs, an astronomer at the Perth Observatory. He added that people don’t really understand and scientists fail to communicate that ‘there is always a chance that the asteroids will change their rating’.
The Torino scale uses five colors to indicate the magnitude of destruction a potential collision can cause. The colors, which remain unchanged as the previous system, have new explanations for each color. For example, asteroids that fall under the green color were called ‘events meriting careful monitoring’, but are now described as ‘normal’.
“When we discover an object, the most likely outcome is that when we have enough data the object will go away. The previous system didn't communicate that,” Binzel concluded, while adding that the Torino system was an ‘information system’ and not a ‘warning system’.
Meanwhile, government bodies have been told to withhold preparation for a level 6 disaster unless the impact is predicted for a time that falls under a decade.
