The European Space Agency’s (ESA) Jupiter Icy Moons Explorer (Juice) lifted off on an Ariane 5 rocket from Europe’s Spaceport in French Guiana on 14 April, 2023.
Key points
- The successful launch marks the beginning of an ambitious voyage to uncover the secrets of the ocean worlds around giant planet Jupiter.
- It will make detailed observations of gas giant Jupiter and its three large ocean-bearing moons – Ganymede, Callisto and Europa.
- It has an eight-year cruise (2031) 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 Israel Space Agency. It is the first Large-class mission in ESA’s Cosmic Vision programme.
Jupiter and Ganymede
- Astronomer Galileo Galilei brought Jupiter into focus in 1610, observing the planet through a telescope for the first time and discovering its orbiting moons. His observations overturned the long-held idea that everything in the heavens revolved around Earth.
- Juice – which carries a commemorative plaque in honour of Galileo’s discoveries – will see Jupiter and its moons in a way that Galileo couldn’t even have dreamt of.
- Three of the planet’s largest moons – Europa, Ganymede and Callisto – hold quantities of water buried under their surfaces in volumes far greater than in Earth’s oceans.
- These planet-sized moons offer us tantalising hints that conditions for life could exist other than here on our ‘pale blue dot’, and Juice is equipped to bring us one step closer to answering this alluring question.
- Ganymede, which is larger than the planet Mercury, is Juice’s primary scientific target; it will spend around nine months observing the moon closely from orbit.
- Ganymede has a particularly intriguing characteristic in addition to its hidden ocean: it is the only moon in the Solar System to generate its own magnetic field. Only two other solid bodies generate a field like Ganymede’s – Mercury and Earth.
