Overview
- At the AAAS meeting, NASA officials said Earth lacks a ready deflection capability as roughly 15,000 medium-size near-Earth asteroids are still unknown.
- Surveys have found about 40% of an estimated 25,000 objects larger than 140 meters, with 11,493 cataloged in that size range and 876 exceeding 1 kilometer in NASA's latest tally.
- Asteroids around 140 meters across can cause regional damage yet often evade optical searches, especially if dark, making thermal infrared detection a priority.
- NASA plans to launch the NEO Surveyor space telescope next year to find both dark and bright objects and to reach a goal of cataloging over 90% of >140-meter asteroids within a decade.
- The 2022 DART test proved kinetic deflection works, but mission leaders, including Nancy Chabot, note no operational spacecraft is available today, and a late-spotted asteroid dubbed YR4 in 2024 illustrated the risks of short warning times.