Frontiers in Astronomy and Space Sciences (May 2024)

The temporal variability of Io’s hotspots

  • A. Mura,
  • F. Zambon,
  • F. Tosi,
  • R. M. C. Lopes,
  • J. Rathbun,
  • M. Pettine,
  • A. Adriani,
  • F. Altieri,
  • M. Ciarniello,
  • A. Cicchetti,
  • G. Filacchione,
  • D. Grassi,
  • R. Noschese,
  • A. Migliorini,
  • A. Migliorini,
  • G. Piccioni,
  • C. Plainaki,
  • R. Sordini,
  • G. Sindoni,
  • D. Turrini

DOI
https://doi.org/10.3389/fspas.2024.1369472
Journal volume & issue
Vol. 11

Abstract

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We investigate the variability of the power emission of Io’s hotspots by using recent Juno/JIRAM infrared observations. The Jovian Infrared Auroral Mapper (JIRAM) is an imaging spectrometer which began observing Jupiter in August 2016. Although observing Jupiter’s moons is not its primary objective, JIRAM can use the frequent opportunities to observe Io (up to once per orbit) to gather infrared images and spectra of its surface. The present study uses the data acquired by JIRAM during the last 2 years, including the location and morphology of Io’s hotspots, and the temporal variability of the total output. A new photometric model for the hotspots and the dayside surface has been developed, which permits us to disentangle the temporal variability from the changes in the observation geometry. While the latitudinal dependence of the power output is not well constrained, low-latitude hotspots show a significantly more intense temporal variability and greater temperature.

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