Extras

    Video thumbnail: Comet Encounter Official Trailer

    Comet Encounter

    Official Trailer

    Airs December 25, 2013 at 10:00 p.m. ET/PT. Check your local listings.

    Official Trailer

    Video thumbnail: Comet Encounter Official Trailer 2

    Comet Encounter

    Official Trailer 2

    Follow a once-in-a-lifetime event — Comet ISON’s brush with the sun.

    Official Trailer 2

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