Europa transits Jupiter’s face along with its own shadow and the shadow of Ganymede overnight tonight. | Published: May 15, 2026 Catch both Ganymede and Europa’s shadows transiting Jupiter late on May 15, along with Europa itself. At this time, Io is occulted by Jupiter and Callisto lies farther east, outside this field of view. Credit: Astronomy: Roen Kelly Looking for a sky event this week? Check out our full  Sky This Week  column.  May 14: The Moon and Mars in the morning Jupiter remains prominent in eastern Gemini after sunset, glowing brightly to the lower left of the Twins’ two heads, Castor and Pollux. Overnight tonight, there’s a double shadow transit visible on the gas giant’s cloud tops, as the shadows of both Europa and Ganymede travel from east to west.  Eastern time zone observers can get started once the sky grows dark to catch Europa itself already transiting the planet. Ganymede’s large shadow is the first shadow to appear, at 9:58 P.M.…