Overview
- NASA’s Kelly Fast told the AAAS meeting that only about 40% of near‑Earth objects 140 meters and larger are cataloged, leaving a large, uncertain population untracked.
- Estimates suggest roughly 15,000 such ‘city‑killer’ asteroids remain undiscovered, with some reports citing totals that imply as many as about 25,000 in this size range.
- Johns Hopkins’ Nancy Chabot, who led NASA’s 2022 DART test, said no comparable spacecraft is ready to launch today if a threatening object were found.
- DART’s impact on the moonlet Dimorphos proved a kinetic strike can alter an asteroid’s path, but experts say real‑world deflection would require time, planning and hardware that does not yet exist.
- NASA’s NEO Surveyor space telescope is expected to launch next year to accelerate discovery, with a goal of finding over 90% of 140‑meter‑class objects within about a decade.