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AsteriaStar
Risk scale

The Torino Scale

A 0–10 scale, like a hazard traffic light, for communicating the risk of a near-Earth object to the public — combining impact probability and energy into a single colour-coded number. Apophis briefly reached level 4, the highest ever, before further observations returned it to zero.

Highlights

  • Apophis reached level 4 — the highest ever recorded

Knowledge connections

Sources

The primary and reference sources this topic draws on.

  • NASANational Aeronautics and Space Administration

    Mission data, planetary science, space telescopes, and public-domain imagery.

    Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.