(slang) A reduced-gravity aircraft, an airplane that briefly provides a nearly weightless environment by flying on a parabolic flight path; used to train astronauts or conduct research.

(astronomy) A low-powered telescope with a large field of view, used for finding comets.

plural of comet-finder

(astronomy, planetology) A comet (or exocomet) located in interstellar space, and not gravitationally bound to a star.

A periodic Jupiter-family comet first recorded in 1772, subsequently splitting in two and not observed since 1852.

Alternative form of Halley's Comet

(astronomy) A comet that has shed its volatiles after numerous passes around the sun.

(television) A display artifact consisting of a smear of color that appears to follow a moving object in the picture. / Used other than figuratively or idiomatically: see comet, tail.

plural of comet tail

(astronomy) A comet that does not return to near the sun in a regular orbit.