On 22 October, the European Space Agency launched its most ambitious deep-space mission to date, as a six-tonne probe named Juice head to Jupiter with the aim of exploring whether its moons, several of which have oceans, can support life. Scientists led by Imperial College London are particularly excited about the possibilities of exploring Europa, Ganymede and Callisto, which will be scanned by Juice to look for signs of habitability. They will also attempt to discover if the oceans of the three moons contain salt water, and if so, if they could be home to life. The probe comprises ten instruments, and has taken more than a decade and approximately €1bn to develop.
The mission will first travel 4.1bn miles in a journey that will take more than eight years. Juice will separate from the rocket about half an hour after launch. It cost more than €1bn to create and its success rate is of great importance to the ESA, particularly given recent project failures. For example, the Schiaparelli probe crashed on Mars in 2016, whilst another mission to Mercury has just been terminated due to rising costs.
Scientists have been interested in the moons of Jupiter for some time, largely as a result of information provided by NASA’s Galileo mission, which lasted between 1989 and 2003, and is considered a huge success. However, Juice will look specifically for signs of habitability, which will include the investigation magnetic fields of Jupiter and Ganymede by the Imperial College London team. The presence of a magnetic field could indicate that there is a conductive salt water ocean beneath the surface of a moon. The general assumption is that such an ocean would also need to be warmed by tidal interactions with Jupiter in order to allow life to exist.