Comet ISON entered STEREO Ahead HI1 field of view
Comet ISON entered STEREO Ahead HI1 field of view. First image was taken at 21:34 UTC on November 20, 2013. Both STEREO spacecraft will have a view of the comet in the COR1 and COR2 coronagraphs in the hours around closest approach on November 28.
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