A new study published in Earth and Planetary Physics by Shenzhen University researchers Shibang Du and Chunyu Ding offers a detailed overview of the internal characteristics of asteroids and comets, emphasizing the crucial role of China's Tianwen-2 mission in their exploration. The paper underscores how radar observations of the near-Earth asteroid 2016 HO3 (Kamo'oalewa) and the active asteroid by Riko Seibo
Tokyo, Japan (SPX) Jul 22, 2025
A new study published in Earth and Planetary Physics by Shenzhen University researchers Shibang Du and Chunyu Ding offers a detailed overview of the internal characteristics of asteroids and comets, emphasizing the crucial role of China's Tianwen-2 mission in their exploration. The paper underscores how radar observations of the near-Earth asteroid 2016 HO3 (Kamo'oalewa) and the active asteroid 311P/PANSTARRS will help illuminate the early evolutionary processes of the solar system.
Asteroids and comets serve as time capsules of the solar system's origins, containing largely unaltered primordial materials. With minimal exposure to planetary-scale weathering, their interiors record a history of collisions and dynamical interactions dating back billions of years. The Tianwen-2 mission, launched in late May 2024, aims to probe these interiors using its Asteroid Internal Structure Detection Radar (AISDR).
AISDR features dual-frequency radar systems: one operating at 130-150 MHz for deep penetration (>50 meters), and another ranging from 300-1500 MHz for fine-scale subsurface imaging. These capabilities make it uniquely suited to examine the small, fast-rotating asteroid 2016 HO3-believed to be either a fragment of the main asteroid belt or lunar ejecta-and determine its internal configuration.
In parallel, AISDR will examine 311P/PANSTARRS, an active asteroid known for its unusual multiple tails, which may be caused by rotational breakup or collisions rather than typical sublimation seen in comets. Using advanced dielectric models such as Looyenga-Landau-Lifshitz, the radar will assess subsurface properties, including dust-to-ice ratios and porosity levels. This analysis will help classify the body's internal structure, whether it be a rubble-pile, pebble-pile, or layered composition.
The mission's findings will contribute significantly to our knowledge of how volatile materials survive in small solar system bodies and shed light on the location and evolution of the ancient snowline-the boundary beyond which ice could persist-in the solar system's formative years.
Research Report:Research progress on internal characteristics of asteroids and comets: implications of Tianwen-2 radar observations
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