Triple Transit

Three of Jupiter's large moons (from left: Europa, Callisto, and Io) cross the face of the planet in this time-lapse view of Hubble Space Telescope images taken during a 42-minute stretch on January 24, 2015. Such triple transits are rarely seen. (Video: NASA, ESA, and the Hubble Heritage Team and G. Bacon - STScI/AURA) (00:05)