Editing Near-Earth object (section)

==== Risk scales ====

There are two schemes for the scientific classification of impact hazards from NEOs, as a way to communicate the risk of impacts to the general public.
[[Image:Torino scale.svg|right|thumb|300px|The [[Torino scale]]. The scale in metres is the approximate diameter of an asteroid with a typical collision velocity]]
The simple [[Torino scale]] was established at an IAU workshop in [[Turin]] ({{langx|it|Torino}}) in June 1999, in the wake of the public confusion about the impact risk of {{mpl|1997 XF|11}}.<ref name="NEO-IAU">{{cite conference |first=Hans |last=Rickman |date=2001 |title=NEO Research and the IAU |pages=97–102 |conference=International Workshop on Collaboration and Coordination among NEO Observers and Orbital Computers |location=Kurshiki City Art Museum, Japan |publisher=IAU |editor-first1=Syuzo |editor-last1=Isobe |editor-first2=Yoshifusa |editor-last2=Asakuro |bibcode=2001ccno.conf...97R}}</ref> It rates the risks of impacts in the next 100 years according to impact energy and impact probability, using integer numbers between 0 and 10:<ref name="torino">{{cite web |title=Torino Impact Hazard Scale |publisher=NASA/JPL CNEOS |url=http://cneos.jpl.nasa.gov/sentry/torino_scale.html |access-date=February 14, 2025 |url-status=live |archive-url=https://web.archive.org/web/20250214111538/https://cneos.jpl.nasa.gov/sentry/torino_scale.html |archive-date=February 14, 2025}}</ref><ref>{{cite journal |title=Torino Impact Hazard Scale |journal=Planetary and Space Science |volume=48 |issue=4 |pages=297–303 |bibcode=2000P&SS...48..297B |last1=Binzel |first1=Richard P. |year=2000 |doi=10.1016/S0032-0633(00)00006-4}}</ref>
* ratings of 0 and 1 are of no concern to astronomers or the public,
* ratings of 2 to 4 are used for events with increasing magnitude of concern to astronomers trying to make more precise orbit calculations, but not yet a concern for the public,
* ratings of 5 to 7 are meant for impacts of increasing magnitude which are not certain but warrant public concern and governmental contingency planning over an increasing timescale,
* 8 to 10 would be used for certain collisions of increasing severity.

The more complex [[Palermo scale]], established in 2002, compares the likelihood of an impact at a certain date to the probable number of impacts of a similar energy or greater until the possible impact, and takes the [[logarithm]] of this ratio. Thus, a Palermo scale rating can be any positive or negative real number, and risks of any concern are indicated by values above zero. Unlike the Torino scale, the Palermo scale is not sensitive to newly discovered small objects with an orbit known with low confidence.<ref name="palermo">{{cite web |title=Palermo Technical Impact Hazard Scale |publisher=NASA/JPL CNEOS |url=https://cneos.jpl.nasa.gov/sentry/palermo_scale.html |access-date=January 2, 2025 |url-status=live |archive-url=https://web.archive.org/web/20231001191140/https://cneos.jpl.nasa.gov/sentry/palermo_scale.html |archive-date=October 1, 2023}}</ref>