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Title: New insights of asteroid 4179 Toutatis using China Chang'e-2 close flyby optical measurements

The mysteries of near-Earth asteroid 4179 Toutatis have been more comprehensively unveiled by analyzing the optical images taken during the Chang'e-2 flyby in 2012. Compared with previous works, this paper concentrates on the photogrammetric relation between the Chang'e-2 spacecraft and Toutatis and the imaging shadow effect during the flyby. Accurate models of imaging and optical measurements are developed to study Toutatis's dimensions and rotational state at the time of imaging. As the illumination study shows, the shadowed region perpendicular to the long axis accounts for 27.78% of the Toutatis images, while the long axis of the body is fully captured. With a compensation on the shadow effect, the optical measurements reveal that Toutatis's long axis is 4354 ± 56 m, the maximum length is 4391 ± 56 m, and the spatial orientation described with the angles of direction cosine during the flyby is (126.°13 ± 0.°29, 122.°98 ± 0.°21, 126.°63 ± 0.°46). Furthermore, a new triaxial ellipsoid of 4354 × 1835 × 2216 m and a volume of 7.5158 km{sup 3} are proposed based on the previous Toutatis shape model. The effectiveness of the proposed method is validated, since typical features such as the neck and endpoints agree well withmore » the results simultaneously observed by the ground radar. Moreover, it also potentially provides a feasible approach to precisely calculate the spin period of Toutatis.« less
Authors:
; ; ; ; ;  [1] ; ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Aerospace Flight Dynamics Laboratory, Beijing Aerospace Control Center, PO Box 5130, Beijing 100094 (China)
  2. Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101 (China)
  3. School of Earth and Space Sciences, Peking University, Peking 100871 (China)
  4. College of Mechatronics and Automation, National University of Defense Technology, 410073 (China)
  5. Institute of Electronics, Chinese Academy of Sciences, 100190 (China)
Publication Date:
OSTI Identifier:
22342162
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 149; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTEROIDS; CAPTURE; EARTH PLANET; ILLUMINANCE; IMAGES; PLANETS; RADAR; ROTATIONAL STATES; SATELLITES; SHADOW EFFECT; SPACE; SPECTRA; SPIN; SURFACES