The probe Juno NASA is getting ready for his objective, Jupiter: the appointment to the insertion in orbit of the largest planet of the solar system is going to be on next July, 4. Among the many activities in preparation for that moment, the scientific team responsible for the Italian instrument JIRAM (InfraRed Jovian Auroral Mapper), one of the ten that equips the scientific payload of the mission, was turned on twice, on January 25 and February 9, to carry out some tests on its camera. Although several months and more than 80 million km are still missing to the orbit insertion, the instrument, which was funded by the Italian Space Agency, built by Finmeccanica s.p.a. and operated under the scientific supervision of the Institute of Astrophysics and Space Planetology (IAPS) INAF has managed to acquire several images of Jupiter and its nearest satellite, Io. "The observations, even if obtained from a long distance, already demonstrate the excellent performance of JIRAM in the view of the beginning of the real observing mission," says Alberto Adriani, IAPS-INAF, principal investigator for the instrument. "JIRAM was also operated in the absence of the pointing information which instead will be at its disposal during the mission and immediately after the orbit insertion."

The instrument is equipped with a spectrometer and a camera capable of working in the infrared spectral range 2-5 microns. The camera is equipped by two color filters optimized to observe both the auroral and the thermal emissions from the planet. The images were acquired during the first test on January 25 and confirmed the excellent performance of the infrared camera. One of the images shows the northern aurora of the planet and, on the right, its moon Io. The second one identifies the thermal emission of the planet and, in particular, that from the equatorial areas which exhibits higher temperatures than the rest of the planet. During the February 9 power-on sequence JIRAM has also acquired many other images. In particular, at this time, the JIRAM team is examining the scientific content of those concerning the satellite Io in order to consider the possibility of a publication of the results got from those new images.