- 4769 Castalia
The asteroid 4769 Castalia (pronEng|kæˈsteɪliə "ka-stay'-lee-ə"; previously known by the
provisional designation 1989 PB) was the firstasteroid to be modeled byradar imaging . It is an Apollo, Mars- andVenus-crosser asteroid . It was discovered onAugust 9 ,1989 byEleanor F. Helin (Caltech ) on photographic plates taken atPalomar Observatory . It is named afterCastalia , anymph inGreek mythology .General information
Castalia's
orbit took it within elevenlunar distance s ofEarth , allowing it to be observed withradar from theArecibo Observatory byScott Hudson (Washington State University ) andSteven J. Ostro (JPL). The data allowed Hudson et al. to produce a three-dimensional model of the object.Castalia has a peanut shape, suggesting two ~800 m diameter pieces held together by their weak mutual gravity. Since then radar observations of other asteroids have found other contact binaries.
ee also
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List of noteworthy asteroids External links
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* [http://echo.jpl.nasa.gov/asteroids/4769_Castalia/cast01.html NASA Asteroid Radar Search - The 228 Radar-Detected Asteroids: Asteroid 4769 Castalia]
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