Chinese-led research team identifies fastest-rotating near-Earth asteroid, advancing early-warning capabilities
A Chinese-led international research team has identified the fastest-rotating near-Earth asteroid known to date and improved methods for determining the physical characteristics of asteroids that require short-term early warning. The findings mark a breakthrough in the observation and study of rapidly rotating near-Earth asteroids and are expected to enhance capabilities for advanced monitoring, early warning and defense against asteroid threats that allow little time for response, the Global Times learned from the research team on Tuesday.
A screenshot from an animation of a Chinese asteroid defense mission (Photo: VCG)
The research team, led by Zhang Xiliang, a researcher at the Yunnan Observatories, Chinese Academy of Sciences, and Fan Xiangyu, a doctoral student at the Yunnan Observatories, working with domestic and international collaborators, has published its findings in the international journal The Astronomical Journal.
Near-Earth asteroids (NEAs) are asteroids with heliocentric distances less than 1.3 au. Those larger than 140 meters and having a minimum orbit intersection distance with Earth of less than 0.05 au are designated as potentially hazardous asteroids (PHAs).
The destructive potential of near-Earth asteroid impacts has attracted growing public attention and concern, making monitoring, early warning and planetary defense against near-Earth asteroids essential to protect humanity.
As of October 10, 2026, about 42,752 near-Earth asteroids had been confirmed, including 2,542 potentially hazardous asteroids, according to the Minor Planet Center of International Astronomical Union. The small size, faintness and high speed of these asteroids make their early detection and accurate assessment of their impact energy extremely challenging. In all the 13 cases to date in which humanity has successfully predicted near-Earth asteroid impacts, the asteroids were meter-sized, and the warning times ranged from two to 21 hours.
Near-Earth asteroid 2024 XA1 entered Earth's atmosphere over eastern Siberia in the early hours of December 4, 2024, Beijing time, just 10 hours after its discovery, marking humanity's 11th successful prediction of an asteroid impact.
To efficiently obtain brightness data for asteroid 2024 XA1, the research team used the 2.4-meter Lijiang Telescope to capture images of asteroid 2024 XA1 during the final hour before it entered Earth's atmosphere.
The research results show that near-Earth asteroid 2024 XA1 has a rotation period of just 1.63 seconds, surpassing the previous record of 2.58 seconds held by asteroid 2024 BX1 to become the fastest-rotating near-Earth asteroid known to date.
The asteroid's extreme rotation generates centrifugal acceleration far exceeding its gravitational acceleration, indicating that it is a solid, strength-dominated monolithic body rather than a loosely gravitationally bound rubble pile. It may have formed through the collision and fragmentation of a larger celestial body.
The study not only confirmed 2024 XA1 as the fastest-rotating near-Earth asteroid known to date but also offered new insights into the internal structure of rapidly rotating, fast-moving meter-scale asteroids and enhanced the ability to characterize short-term warning asteroids.