Comets' Orbits

Comet orbits remained mysterious. Halley claimed that comet orbits were elliptical, just very elongated. At the time, he was not taken seriously, but when he successfully predicted the return of a comet 50 years later, he was vindicated posthumously.
 Edmund Halley England 1705 Comets' Orbits

Comet orbits remained mysterious. Halley claimed that comet orbits were elliptical, just very elongated. At the time, he was not taken seriously, but when he successfully predicted the return of a comet 50 years later, he was vindicated posthumously.