Juice flyby of Europa (artist’s impression)

Could there be – or has there ever been – life in the Jupiter system?

Since the Voyager spacecraft passed by Jupiter and its moons in 1979, providing the first hints that Europa might contain liquid water, scientists have been desperate to answer this weighty conundrum. Digging deeper will be a key aim of ESA’s Jupiter Icy Moons Explorer, Juice, which will make two flybys of distinctly grooved Europa in the early 2030s, approaching as close as 400 km.

During these close encounters, Juice will characterise the composition and chemistry of Europa’s surface, hunting for substances that are essential to support life (‘biosignatures’). Scientists have found strong evidence that Europa has an ocean of liquid water under its icy shell, and the moon may vent water vapour to space via ‘plumes’ and geysers. Juice will search for pockets of water in the moon’s shallow subsurface using unprecedented ice-penetrating radar, and reveal locations where the transfer of material between subsurface, surface and space may be especially intense.

Juice will explore Europa by…

• …characterising the composition and chemistry of its surface, including searching for biosignatures and exploring how both internal and external factors (including tectonics, cryovolcanism and surface erosion) have shaped Europa’s surface over time;
• …searching for liquid water under Europa’s most active sites, from probing the crust (which may be only a few kilometres thick in places) to surveying the depth of the moon’s subsurface ocean;
• …studying these active sites and processes themselves, revealing their geology, composition, and any current levels of activity.

Discover more about Juice and Jupiter’s icy moons.

ESA’s Jupiter Icy Moons Explorer, Juice, is humanity’s next bold mission to the outer Solar System. It will make detailed observations of gas giant Jupiter and its three large ocean-bearing moons – Ganymede, Callisto and Europa. This ambitious mission will characterise these moons with a powerful suite of remote sensing, geophysical and in situ instruments to discover more about these compelling destinations as potential habitats for past or present life. Juice will monitor Jupiter’s complex magnetic, radiation and plasma environment in depth and its interplay with the moons, studying the Jupiter system as an archetype for gas giant systems across the Universe.  

Juice launches on an Ariane 5 from Europe’s Spaceport in Kourou in April 2023. It has an eight year cruise with flybys of Earth and Venus to slingshot it to Jupiter. It will make 35 flybys of the three large moons while orbiting Jupiter, before changing orbits to Ganymede.

Juice is a mission under ESA leadership with contributions from NASA, JAXA and the Israeli Space Agency. It is the first Large-class mission in ESA’s Cosmic Vision programme.