Overview

• A Nature Communications study confirms asteroid 1998 KY26 is about 11 meters across with a roughly five-minute rotation and a bright surface, overturning earlier ~30-meter, ~10-minute estimates.
• Researchers combined a 2024 close-approach campaign using ESO’s Very Large Telescope, Gemini South, SOAR, Blanco/DECam, and GTC with prior radar data to refine the asteroid’s properties.
• The smaller size, higher reflectivity, and rapid spin complicate navigation and brief touchdown attempts, leading teams to reassess mission operations.
• JAXA still targets a July 2031 rendezvous with KY26 following a planned 2001 AV43 visit in November 2029, and no schedule change has been announced.
• KY26’s internal structure remains uncertain—potentially solid rock or a loose rubble pile—and the results showcase new ground-based capabilities to characterize decametre-scale near-Earth objects important for planetary defense.