WIREDGOV

A new mission to explore Jupiter and its icy moons has been approved by the European Space Agency (ESA). The mission will reveal fresh insights into the habitability of the ‘waterworlds’ orbiting the giant planets in our solar system and beyond.

On 2 May 2012, at a meeting in Paris, ESA’s Science Program Committee voted to go ahead with the project, the Jupiter Icy Moons Explorer (JUICE), the first European-led mission to the outer solar system, and the first spacecraft destined to orbit an icy moon. The JUICE spacecraft is scheduled to launch in 2022, arriving in the Jupiter system in 2030. JUICE will contribute to key questions in the STFC Science Roadmap.

The selection of the Jupiter mission is the culmination of five years of hard work by the ESA team of scientists and engineers. ESA’s Cosmic Vision L-class competition started in March 2007 with a call to the scientific community to propose new ideas for future exploration.

The JUICE mission relies on a strong heritage of outer solar system exploration by UK scientists, such as those involved in the Cassini-Huygens mission to Saturn and Titan, and UK researchers have been deeply involved in the leadership and planning for JUICE. Several universities have played a vital role in gaining approval for the mission, including UK scientists and researchers from Imperial College London, Oxford University, University of Leicester, and UCL (University College London).

The primary target of the mission is the solar system’s largest moon, Ganymede, an icy world 8% larger than the planet Mercury. Ganymede is unique within the solar system – it is thought to harbour a deep ocean under the icy crust, it has its own internally generated magnetic field, and it has an ancient surface littered with more individual types of crater than anywhere else in the solar system.

If moons are common features of giant planets around other stars, then Ganymede may represent a whole class of potentially habitable environments in our galaxy. JUICE will carry experiments designed to study the sub-surface ocean, the geology and composition of the surface, and its interaction with its plasma environment, to assess its potential as a habitable environment in our solar system. The spacecraft will also investigate Jupiter’s other icy worlds, Callisto and Europa, as well as the giant planet’s complex atmosphere and extended magnetosphere.

The JUICE mission relies on a strong heritage of outer solar system exploration by UK scientists, such as those involved in the Cassini-Huygens mission to Saturn and Titan.

Proposing instruments for JUICE will be several universities, including Imperial, Oxford, Leicester and University College London. These instruments will be specifically designed to study the gas giant, its icy moons and charged particle environment to an unprecedented level of detail, giving our most detailed characterisation of the jovian system ever obtained.

As well as making close measurements of the surface, sub-surface, magnetic and plasma environment of Ganymede the mission will also focus on the other icy moons; performing multiple flybys of Callisto and two flybys of Europa. By studying all three of these icy environments the mission’s studies of Ganymede will take on a broader significance.

In order to assess whether Jupiter and its moons could provide habitable environments, and provide a model for gas giant systems orbiting other stars, the spacecraft will make an extensive study of the planet’s dynamic, evolving atmosphere, with its belts, zones and gigantic swirling storms, over the 3-year duration of the mission. JUICE will also study the magnetic and charged particle environment of Jupiter, which has the largest magnetosphere in the solar system, and its coupling to the moons (particularly Ganymede).