A €1 billion mission to study the icy moons of Jupiter has been chosen as Europe's next large-scale space mission ahead of rival bids to study gravitational waves and observe the universe at x-ray wavelengths. The European Space Agency's (ESA's) Jupiter Icy Moons Explorer (JUICE) will investigate the Galilean moons Europa, Ganymede, and Callisto. Scientists believe the moons are potential homes of primitive life and could be models for life on moons beyond our solar system.
JUICE was approved by ESA Science Programme Committee at a meeting in Paris today. It will be the first L-class mission in the agency's Cosmic Vision 2015-2025 program. It was picked ahead of the New Gravitational Wave Observatory (NGO), a scaled-down version of the LISA gravitational-wave mission, and ATHENA, the Advanced Telescope for High-Energy Astrophysics.
JUICE is scheduled to be launched in 2022 and will make detailed observations of Jupiter and its moons for at least 3 years following its arrival at the solar system's largest planet in 2030. After visiting Callisto and measuring the thickness of the icy crust of Europa, plans call for JUICE to enter into orbit around Ganymede in 2032, studying the moon's icy surface and subsurface ocean. It will also observe the interaction of Ganymede's magnetic field and the Jovian magnetosphere.
"Jupiter is the archetype for the giant planets of the solar system and for many giant planets being found around other stars," says Alvaro Giménez Cañete, ESA's director of science and robotic exploration. "JUICE will give us better insight into how gas giants and their orbiting worlds form, and their potential for hosting life."
In a statement, ESA said that the Science Programme Committee recognized the "high scientific value" of both NGO and ATHENA and that technology will continue to be developed for these mission proposals, allowing them to "be considered as candidates for future launch opportunities." ESA is expected to issue a second call for large missions in 2013; the first competition began in 2007.