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Jovian Infrared Auroral Mapper is an instrument on the Juno spacecraft in orbit of the planet Jupiter. It is an image spectrometer and was contributed by Italy. Similar instruments are on ESA Rosetta, Venus Express, and Cassini-Huygens missions. The primary goal of JIRAM is to probe the upper layers of Jupiter's atmosphere down to pressures of 5–7 bars at infrared wavelengths in the 2–5 μm interval using an imager and a spectrometer. The Jupiter's atmosphere and auroral regions are targeted for study. In particular it has been designed to study the dynamics and chemistry in the atmosphere, perhaps determining the how Jovian hot spots form.
H3 ions, ammonia, and phosphine can be mapped. The ion of Hydrogen H3 is rare on Earth, but is one of the most common ions in the universe and known as protonated molecular hydrogen or the trihydrogen cation.
Despite the intense magnetosphere of Jupiter, the JIRAM is expected to be operational for at least the first eight orbits.
Previously Jupiter was observed by an Infrared imaging spectrometer called NIMS on the Galileo Jupiter orbiter. JIRAM was used to observe Earth during its flyby en route to Jupiter. These observations were used to help calibrate the instrument, and the lunar observations were actually a critical planned step in preparing the instrument for observations at Jupiter. The polar orbit of the Juno mission permits to get unprecedented observations of the planet. In particular, the polar regions, that where never observed before Juno, can be observed with high spatial resolution.