See also: Palermo Technical Impact Hazard Scale
A risk-assessment scale, with integer values from 0 to 10, used to describe an approach of a particular asteroid to Earth in terms of the likelihood and consequences of its collision with Earth
See also: Palermo Technical Impact Hazard Scale
A risk-assessment scale, with integer values from 0 to 10, used to describe an approach of a particular asteroid to Earth in terms of the likelihood and consequences of its collision with Earth. The scale was devised by Richard P. Binzel and first presented at a conference in 19951. A revised version was approved at an International Astronomical Union (IAU) workshop in Torino (Turin), Italy in 1-4 June 1999 and formally adopted by the IAU in an announcement at the UNISPACE III conference in Vienna on 22 July 1999.
|Events Having No Likely Consequences||0||The likelihood of a collision is zero, or well below the chance that a random object of the same size will strike the Earth within the next few decades. This designation also applies to any small object that, in the event of a collision, is unlikely to reach the Earth's surface intact.|
|Events Meriting Careful Monitoring||1||The chance of collision is extremely unlikely, about the same as a random object of the same size striking the Earth within the next few decades.|
|Events Meriting Concern||2||A somewhat close, but not unusual encounter. Collision is very unlikely.|
|3||A close encounter, with 1% or greater chance of a collision capable of causing localized destruction.|
|4||A close encounter, with 1% or greater chance of a collision
capable of causing regional devastation.
|Threatening Events||5||A close encounter, with a significant threat of a collision capable of causing regional devastation.|
|6||A close encounter, with a significant threat of a collision capable of causing a global catastrophe.|
|7||A close encounter, with an extremely significant threat of a collision capable of causing a global catastrophe.|
|Certain Collisions||8||A collision capable of causing localized destruction. Such events occur somewhere on Earth between once per 50 years and once per 1000 years.|
|9||A collisio