Juice: The Billion-Pound Probe Blasting Off to Hunt for Extraterrestrial Life on Jupiter's Icy Moons

The ice on Europa, one of Jupiter’s moons, covers vast oceans of liquid water – and one of our best hopes of finding extraterrestrial life.NASA/JPL-CALTECH/SETI INSTITUTE

 In a few days, the Jupiter Icy Moons Explorer (Juice) will be launched on an eight-year mission to find signs of life on the icy moons of distant Jupiter. Juice will explore the greatest reserves of water that exist on worlds far from Earth, in deep space and in orbit around the giant planets Jupiter and Saturn. The mission aims to find places around Jupiter where life could have started and to discover more water than on Earth.

Juice will focus on Ganymede, the largest moon in the solar system. After a series of visits to Callisto and Europa, Juice will enter into a permanent orbit around Ganymede in 2034. It will be the first time a spacecraft has ever held an orbit around a moon other than our own.

The Jupiter Icy Moons Explorer being fuelled for launch before its eight-year journey to explore Jupiter’s ocean-bearing moons. Photograph: ESA/CNES/Arianespace/PA

Nasa’s Europa Clipper, on the other hand, will take a shorter route using flybys of Earth and Mars, to arrive at Europa in April 2030. The US spacecraft will focus on Europa and is scheduled to make 50 close approaches of the moon, sweeping a few hundred miles over its surface to try to spot areas that could support life.

If these missions find that life has evolved twice, separately, in our own solar system, it would indicate that it is likely to be widespread throughout the galaxy. Results could be revolutionary.

Getting there is a different matter, however. Journeys to Mars take about eight months. By contrast, Juice will take about eight years to reach Jupiter, a journey that will require a series of flybys of Earth and Venus to keep it up to speed.

Juice’s blast-off will be watched with bated breath by the scores of European scientists who have collaborated on the project and who will watch as it is carried aloft on an Ariane 5 launcher, the same rocket that placed the James Webb space telescope on a perfect trajectory on Christmas Day 2021. They will be hoping for a repeat performance.

In conclusion, Juice's mission to explore the icy moons of distant Jupiter will open up a new chapter in the hunt for extraterrestrial life. If successful, the mission could reveal that life exists not only on Earth but also on other worlds in our solar system. With close collaboration between the European Space Agency (Esa) and Nasa, the two missions, Juice and Europa Clipper, could yield revolutionary results that would change our understanding of the universe.

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