"one of a class of celestial bodies which move about the sun in great, elliptical orbits," c. 1200, from Old French comete (12c., Modern French comète), from Latin cometa, from Greek (aster) kometes, literally "long-haired (star)," from kome "hair of the head" (compare koman "let the hair grow long"), which is of unknown origin. So called from resemblance of a comet's tail to streaming hair.
Visible only when near the sun, they were anciently regarded as omens of ruin, pestilence, and the overthrow of kingdoms. Halley in 1682 established the fact that many were periodic. Comet-wine (1833), that made in any year in which notable comets have been seen, was reputed to have a superior flavor (the original reference is to the Great Comet of 1811). Related: Cometary; cometic; cometical.
Their sudden appearance in the heavens, and the imposing and astonishing aspect which they present, have, even in recent times, inspired alarm and terror. One however--the splendid comet of 1811--escaped somewhat of the general odium; for as it was supposed to be an agent concerned in the remarkably beautiful autumn of that year, and was also associated with the abundant and superior yield of the continental vineyards, the wine of that season was called the comet wine. ["The Leisure Hour," April 15, 1852]
Beware of wine named after noted vintages long passed, which is generally a clap-trap, the genuine wines being all before secured for years in private stocks. If "comet wine," or any other noted vintage, be offered, decline it, and nine times out of ten you escape an imposition. [Cyrus Redding, "Every Man His Own Butler," London, 1852]