The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
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EAS's Jupiter Icy Moons Explorer (Juice) will spend years in the Jovian system exploring the gas giant Jupiter, its space environment, and its intriguing satellites.
Juice will pay particular attention to Jupiter's 'Galilean Moons', Io, Europa, Ganymede, and Callisto, with special focus on the latter three. Their name comes from the Italian astronomer Galileo Galilei, who first observed these four moons through a telescope in 1610. But how do those moons compare to our own Moon? Whilst Io and Europa are relatively similar in size to the Moon, Juice's final destination Ganymede is quite a lot bigger.
Read more on what Juice will discover about the moons of Jupiter
[Image description: An infographic that displays Jupiter (diameter: 142 984 km) and its moons Io (3643 km), Europa (3122 km), Ganymede (5262 km) and Callisto (4821 km), together with Earth (12 756 km) and its Moon (3475 km).]