1956 2 1001 The gegenschein is a quite different phenomenon, namely the emission by a gas tail given off by the Earth.
1983 71 411/3 Cometary happenings (split nuclei, detachments, striations, motions of knots in gas tails, antitails, etc.).
2001 M. D. Reynolds i. 7 In 1997 Comet Hale-Bopp..exhibited both a spectacular blue gas tail and a yellow dust tail.