Apollo s Analemma . ... Credit Copyright: Anthony Ayiomamitis ( TWAN ) Explanation: Today, the Sun crosses the celestial equator heading south at 20:44 Universal Time. An equinox (equal night), this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. ... Exposures were made at the same time of day (9:00am local time), capturing the Sun's position on dates from January 7 through December 20, 2003. ... NASA Official: Jay Norris. ...