June 22nd in Astronomy and Space Science
![]() | 1675 | Royal Greenwich Observatory founded in Greenwich, England. Greenwich Observatory was chosen to be the prime meridian - defining east and west longitude, and the basis for the world's time zones by a vote of 25 nations at The International Meridian Conference in 1884. The exact line that divides east longitude from west is defined as the north-south line that passes through the crosshairs in the eyepiece of the transit telescope in Royal Greenwich Observatory. |
![]() | 1978 | American astronomer James Christy discovers Charon, the moon of Pluto. He was working on photographic plates from the 1.55 m (61 inch) reflector at the US Naval Observatory in Flagstaff, Arizona on a project to refine Pluto's orbit. The moon appeared as a elongation in the shape of Pluto that shifted in position with a period of about 6 days. It was christened Charon after the mythological ferryman who carried souls across the river Styx to Pluto's underworld. |