Apr2818AASAstroFacts 600

 Comets are usually named for their discoverers, but not Halley’s. Edmond Halley (1656-1741) figured out that the comet now named for him returns about every 76 years, confirming that comets are in closed orbits around the Sun. It’ll be back in 2061. #gam2018 #RandomAstroFact