Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometri...Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometric array designed for low-frequency Sun imaging,presents a promising tool for probing asteroid interiors.With a substantial 1-km array aperture and an equivalent receiving area of approximately 8,850 m2,DART plays a vital role in diagnosing asteroid internal structures.This study introduces an electromagnetic wave scattering model tailored to asteroids within DART’s operational frequency range(150 to 450 MHz).Ground-based radar detection can unveil multiple facets of these celestial bodies by leveraging low-frequency waves’penetrating capabilities and capitalizing on asteroids’rotational dynamics.Through simulations capturing the characteristics of low-frequency waves traversing a layered model and interacting with internal structures,we propose an electromagnetic scattering model of asteroids.Our results underscore DART’s potential as a crucial instrument for discerning the internal structure of near-Earth objects.We first formulate an asteroid model through celestial impact models,dimensional analysis,and data fitting to achieve this.Subsequently,we derive an electromagnetic scattering model using geometric optics and a propagation model for lossy mediums.Simulations demonstrate that morphology and internal structure dictate the distribution of scattered waves,with forward and backscattered waves providing comprehensive internal structure information over a rotation cycle.Furthermore,we observe that alterations in electromagnetic wave frequency induce changes in the scattering characteristics,prompting the convenience of employing multiple frequencies for retrieving detailed information about an asteroid’s internal medium and structure.This multidimensional approach positions DART as a promising asset in advancing our understanding of asteroid interiors,offering valuable insights for scientific inquiry and hazard mitigation strategies.展开更多
基金supported by the National Nature Science Foundation of China(grant no.42004139)High-Precision Localization Method for Near-Earth Asteroids(grant no.E32623A0)the Research Project of Civil Aerospace Technologies(grant no.KJSP2023020106).
文摘Understanding the internal structure of asteroids is crucial for deciphering their formation and establishing defenses against potential hazards.The Daocheng Radio Telescope(DART),a recently constructed interferometric array designed for low-frequency Sun imaging,presents a promising tool for probing asteroid interiors.With a substantial 1-km array aperture and an equivalent receiving area of approximately 8,850 m2,DART plays a vital role in diagnosing asteroid internal structures.This study introduces an electromagnetic wave scattering model tailored to asteroids within DART’s operational frequency range(150 to 450 MHz).Ground-based radar detection can unveil multiple facets of these celestial bodies by leveraging low-frequency waves’penetrating capabilities and capitalizing on asteroids’rotational dynamics.Through simulations capturing the characteristics of low-frequency waves traversing a layered model and interacting with internal structures,we propose an electromagnetic scattering model of asteroids.Our results underscore DART’s potential as a crucial instrument for discerning the internal structure of near-Earth objects.We first formulate an asteroid model through celestial impact models,dimensional analysis,and data fitting to achieve this.Subsequently,we derive an electromagnetic scattering model using geometric optics and a propagation model for lossy mediums.Simulations demonstrate that morphology and internal structure dictate the distribution of scattered waves,with forward and backscattered waves providing comprehensive internal structure information over a rotation cycle.Furthermore,we observe that alterations in electromagnetic wave frequency induce changes in the scattering characteristics,prompting the convenience of employing multiple frequencies for retrieving detailed information about an asteroid’s internal medium and structure.This multidimensional approach positions DART as a promising asset in advancing our understanding of asteroid interiors,offering valuable insights for scientific inquiry and hazard mitigation strategies.
