Overview
- At the AAAS meeting in Phoenix, planetary defense officer Kelly Fast warned that untracked mid‑sized near‑Earth asteroids remain a major concern.
- Research cited estimates roughly 25,000 asteroids at least 140 meters across exist, with about 40% found and about 15,000 still unaccounted for.
- Scientists say many of these objects are difficult to detect because they are dark or approach from sunward directions that defeat optical surveys.
- NASA’s 2022 DART mission showed kinetic impact can alter an asteroid’s path with sufficient lead time, but no spacecraft is ready for rapid deflection today.
- Planned detection upgrades include the NEO Surveyor telescope, which aims to find most hazardous 140‑meter objects within a decade, alongside enhanced ground surveys by the Vera C. Rubin Observatory.