Leicester scientists on Jupiter moon mission look ahead to launch date

Planetary scientists from the University of Leicester are eagerly waiting the launch of a mission to investigate the solar system’s largest planet, Jupiter, and its mysterious moons later this week.

They are among the science team for ESA’s Jupiter Icy Moons Explorer (Juice), which will observe the giant gas planet Jupiter and its three large ocean-bearing moons: Ganymede, Callisto and Europa. These moons are crucial to understand if life could ever have existed beyond Earth.

Juice will launch on an Ariane 5 from Europe’s Spaceport in Kourou, planned for 13 April 2023.

Professor Emma Bunce is Director of the Institute for Space at the University of Leicester. She is also a Co-Investigator on the JUICE J-MAG and UVS instruments, and Co-Lead of the newly formed ESA JUICE/NASA Europa Clipper Steering Committee. 

Professor Bunce said: “The JUICE mission represents the next logical step in our exploration of potentially habitable worlds in the outer solar system. The JUICE spacecraft will do that via multiple flybys of Europa, Ganymede and Callisto, and eventually from a dedicated orbit at Ganymede towards the end of the mission. After many years of hard work from science, engineering, and industry teams, we are so excited that the JUICE mission is finally ready to launch and start its long journey to the Jupiter system. We will patiently await the incredible data that we expect to receive from 2031, and we are confident that it will absolutely be worth the wait!”

ESA’s Jupiter Icy Moons Explorer, Juice, is humanity’s next bold mission to the outer Solar System. This ambitious mission will characterise the moons Ganymede, Callisto and Europa with a powerful suite of remote sensing, geophysical and in situ instruments to discover more about these compelling destinations as potential habitats for past or present life. 

The University of Leicester planetary scientists will use remote sensing from JUICE, across the electromagnetic spectrum from the ultraviolet to the sub-millimetre and radio, to understand how energy and material flows through the complex atmosphere of Jupiter, from the churning colourful cloud-tops to the dancing auroral lightshows of the ionosphere, and vice versa.

Professor Leigh Fletcher has been involved in the JUICE mission since 2008, and is one of three interdisciplinary scientists (IDS) for the JUICE mission, and the only one based in the UK.  

Professor Fletcher said: “JUICE provides a means of probing inside potentially-habitable ocean worlds of our solar system for the first time, down into the deep, dark, hidden oceans that might be the most suitable abodes for life in our Solar System beyond Earth.  If JUICE can reveal that these distant icy worlds provide genuinely habitable environments, then it has profound implications for the continued search for life, far beyond the classical ‘goldilocks zone’.

“My particular focus is the scientific exploration of Jupiter itself, ensuring that the spacecraft, the orbital tour, and the individual instruments can all work together in harmony to explore the processes shaping Jupiter’s atmosphere as an archetype for giant planets in our solar system and beyond.

“The results from JUICE will significantly enhance ongoing studies at Leicester of the Jupiter system using Juno, JWST, and ground-based observatories, which have explored Jupiter’s belt/zone structure, and shown that Jupiter’s bands exhibit periodic but unexplained cycles of weather and climate over long spans of time.  The end goal of all this is to be able to predict the weather, climate, and chemistry of Jupiter, as an archetype for giant planets – a long term Jovian weather forecast.”

Professor Nigel Bannister said: “The challenges that had to be overcome to make JUICE happen were formidable. JUICE represents more than a decade of work for an international team of scientists and engineers, and launch marks the beginning of an eight year journey to its destination. My work on JUICE concerns the radiation environment around Jupiter, and how to protect the J-MAG instrument from being damaged by the high energy particles concentrated in the space around the planet by its vast and powerful magnetic field. To have been able to work on instrumentation that will ultimately be placed into orbit around one of the moons which Galileo discovered as a tiny point of light in his telescope in 1610, is an enormous privilege.”

Leicester’s scientists will work with three of the instruments on Juice:

• MAJIS, the Moons and Jupiter Imaging Spectrometer, led by the Institut d’Astrophysique Spatiale, France, which will observe cloud features and atmospheric constituents on Jupiter, and will characterise ices and minerals on the icy moon surfaces. 

• UVS is a UV imaging spectrograph, led by the Southwest Research Institute, USA, to characterise the composition and dynamics of the exospheres of the icy moons, to study the Jovian aurorae, and to investigate the composition and structure of the planet’s upper atmosphere 

• J-MAG is the Juice magnetometer, led by Imperial College London, is equipped with sensors to characterise the Jovian magnetic field and its interaction with that of Ganymede, and to study the subsurface oceans of the icy moons.

Since the formation of the University of Leicester’s Space Research Group, now the largest in Europe, it has been involved in more than 90 space missions and had at least one instrument operating in space in each year since 1967. Space Park Leicester, officially opened by British astronaut Tim Peake in March 2022, builds on Leicester’s 60-plus year heritage as a hub for the UK space sector and collaborator with international space agencies.

The massive gas giant Jupiter and its moons have long been a focus of space scientists at Leicester, and the University is home to the only formal UK science lead for the Juno mission, NASA's programme to study our solar system's largest planet. Their research into Jupiter includes investigating solutions to the gas giant’s ‘energy crisis’ and recently releasing some of the sharpest images of Jupiter's moons ever acquired from a ground-based observatory. 

• Juice is an ESA mission with contributions from NASA, JAXA and the Israeli Space Agency.

• Professors Emma Bunce, Leigh Fletcher & Nigel Bannister will be speaking at Exploring Ocean Worlds with the ESA Jupiter Icy Moons Explorer on 25 April.