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The Science Surprise of Juno’s Stellar Reference Unit – how a low-light engineering camera became a high-profile science instrument on NASA’s Juno Mission to Jupiter


Feb. 17, 2023, 3:30 p.m. - 5:30 p.m.
Slichter 3853

Presented By:
Heidi N. Becker
Jet Propulsion Laboratory, California Institute of Technology

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Results from NASA’s Juno Mission have yielded multiple discoveries about Jupiter’s nature, giving us an entirely new, up close view of the gas giant. Several of Juno’s scientific gains have come from an unexpected source - Juno’s innovative use of its low-light sensitive Stellar Reference Unit (SRU) star camera as a high-resolution, visible wavelength science imager. Designed and primarily used to detect dim stars for navigation, the SRU has proven itself a valuable investigative tool, capable of unique science. The engineering characteristics of the camera enabled the discovery of “shallow lightning” on Jupiter’s dark side - small flashes which suggest the presence of high-altitude ammonia-water clouds in Jupiter’s atmosphere. Images of the surfaces of Ganymede and Europa, dimly lit by “Jupiter-shine”, provide fascinating views of puzzling geologic formations never before imaged at such high resolution. The first images of Jupiter’s faint and mysterious ring system to be collected from inside the ring looking out were acquired by the SRU, and its added use as an in situ particle detector for “Radiation Monitoring” has provided significant insights into previously unexplored regions of Jupiter’s extreme radiation environment, including the discovery of a trapped >100 MeV/nucleon heavy ion population within the inner edge of Jupiter’s relativistic electron belt. The SRU has embarked on Juno’s Extended Mission as full-fledged member of Juno’s science payload, with exciting observations yet to come. Heidi Becker, Lead Co-Investigator for Juno’s SRU, shares the journey of how a low-light engineering camera became a high-profile science instrument on NASA’s Juno Mission to Jupiter.