This true color mosaic of Jupiter was constructed from images taken by the narrow angle camera onboard NASA's Cassini spacecraft starting at 5:31 Universal time on December 29, 2000, as the spacecraft neared Jupiter during its flyby of the giant planet. It is the most detailed global color portrait of Jupiter ever produced... -- NASA/JPL/SSI 
The Galilean satellite Io floats above the cloudtops of Jupiter in this image captured two days after Cassini's closest approach... -- NASA/JPL/University of Arizona 
On January 15, 2001, Cassini resumed repeated imaging of Jupiter as it began its departure from the Jovian system. At this time, and throughout the departure phase, only a planetary crescent was visible... -- NASA/JPL/University of Arizona 
This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft's Jupiter flyby in early 2007... -- NASA/JHU/APL Mission to Jupiter -- With its suite of science instruments, Juno will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. Juno's principal goal is to understand the origin and evolution of Jupiter. Underneath its dense cloud cover, Jupiter safeguards secrets to the fundamental processes and conditions that governed our solar system during its formation.
Mission Timeline: Launch - August 2011; Earth flyby gravity assist - October 2013; Jupiter arrival - August 2016
Image credit: NASA/JPL