Rome, 12 June 2023 - Among the remote sensing instruments on board the ESA Jupiter Icy Moon Explorer (JUICE) spacecraft, the Moons and Jupiter Imaging Spectrometer (MAJIS), operating in the visible and near-infrared (0.5-5.5 μm), has particular relevance for its ability to provide essential measurements for the entire range of surveys involving Jupiter and its major icy moons. As for JANUS, RIME and 3GM - all built with funding from the Italian Space Agency (ASI) - MAJIS was also successfully turned on and tested in orbit (commissioning phase): both channels proved to work very well.

Giuseppe Piccioni, Co-Principal Investigator of the MAJIS instrument for INAF in Rome, explains: “Last week, the scanning mirror and shutter were activated and operated flawlessly. Observations of its internal calibration sources were performed, confirming the performances of the instrument aligned with the on-ground calibration. MAJIS is now ready to fulfil its mission, namely to study the surface composition and the exosphere of the icy moons and to characterise the composition and the dynamics of the atmosphere of Jupiter".

Among the objectives of MAJIS, the determination and mapping of the surface composition of the moons Ganymede, Callisto, and Europa are of the utmost importance, with particular emphasis on compounds other than water ice already known from previous observations or predicted by models, such as hydrated mineral salts, volatiles and organic compounds, and compositional mapping of the planet's atmosphere, including cloud density and aurora morphology. In this context, the MAJIS project aims to enhance and further develop the skills gained during the Jovian InfraRed Auroral Mapper (JIRAM) project operating around Jupiter on the NASA Juno mission.

“The completion of the first flight tests of the MAJIS instrument - says Raffaele Mugnuolo, head of Exploration, Infrastructures and Scientific Satellite Department at ASI - is a crucial step and one that instils great optimism for the continuation of the JUICE mission. The MAJIS spectrometer confirms the great and consolidated Italian capacity in this field for the engineering and scientific teams. The coordination exercised by ASI has proved effective in relations with CNES and towards ESA. It has allowed the completion of a complicated instrument that will pay off in unprecedented scientific return".

The MAJIS instrument was built by a French-Italian consortium led by Institut d’Astrophysique Spatiale in Orsay, France, with CNES and ASI's support. The Italian contribution comes from INAF, the Istituto Nazionale di Astrofisica, with help from ASI and the industrial contract for the optical head from Leonardo S.p.A. in Florence. The instrument was initially assembled and calibrated at Leonardo, then at IAS-Orsay. Finally, it was housed aboard the JUICE satellite in December 2021. Belgian laboratories supported by Belspo were involved in characterising the MAJIS detectors.

Contacts:

INAF press office - Marco Galliani, ufficiostampa@inaf.it, +39 3351778428

ASI press office - Giuseppina Piccirilli, stampa@asi.it, +39 335 7821912