Winter Solstice on December 22nd. This is officially the longest night of 2015, (even though the year's earliest sunset occurs two weeks earlier). The Geminid meteors on the night of the 13th-14th. Watch out for this reliable shower.
Capricornus, the Sea Goat: Sign of the Zodiac for birth dates between 22 December and 19 January; it is the leading constellation of the "wet" or "water" constellations. Capricornus has a symmetrical shape resembling a bikini bottom, but the stars of Capricornus are very faint with no star brighter than the third magnitude. Capricornus appears low in the southern sky (never at higher altitudes). The Tropic of Capricorn (23.5 degrees South latitude) is named after Capricornus; on 22 December (on average), the Sun is directly overhead (at the zenith) at Noon along the Tropic of Capricorn. In Mythology, the Greeks identified Capricornus with Pan, the god of nature, who was pictured as half-man, half-goat. In fear, Pan escaped the giant Typhon by leaping into the Nile River and changing his tail to that of a fish. This is the origin of the word, "panic."