What is the Palermo scale and the Turin scale?
The potential danger of so-called near-Earth objects, asteroids or comets is classified on the Palermo scale. “The scale compares the hazard potential of detected objects with the average hazard up to the time of potential impact,” explains NASA's Near-Earth Object Center.
The average risk resulting from random effects is called background risk.
The scale is logarithmic, so for example a value of -2 on the Palermo scale indicates that a potential impact event is only 1 percent more likely to occur than a random background risk, a value of zero means that one event is as threatening as the background risk, + a value of 2 indicates an event that is more It is 100 times more likely to occur than the potential background impact of an object and, furthermore, well before the time of the relevant potential impact.
NEOs are also given a so-called “Torino” score, on a scale from 0 to 10, where 0 means the probability of a collision is zero or close, and 10 means a collision is “certain, causing a global catastrophe.” “A climate catastrophe and could threaten the future of civilization as we know it, whether its impact affects land or the oceans.” One such exciting recent object was the asteroid 99942 Apophis. After its discovery in 2004, observations placed it for the first time at level 2 on the Turin scale.
However, new observations made in December 2004 raised the asteroid's danger to level 4, as the chance of the asteroid colliding with Earth in 2029 rose to 1.6 percent based on trajectory calculations at that time. But further observations after that actually ruled out the possibility of a collision in 2029, as well as in 2036 and 2068, although these would still be very close encounters.
An asteroid with a diameter of more than a kilometer will come very close to Earth