“Say farewell to 2016 in cosmic style by looking up to see the #NewYearsEve #comet on December 31,” the laboratory said in a Wednesday Instagram post. Say farewell to 2016 in cosmic style by looking up to see the #NewYearsEve #comet on December 31 YZ< #NewYear #astronomy #nightsky #comet45p #planets #NASA #JPL #WhatsUp #NYE #newyears The comet, NASA said, was expected to appear in the western horizon on Dec. 15 and had a bluish-green head by Dec. 21. The comet is a periodic comet, which returns to the inner solar system about every 5 years.