The temporal variability of Io's hotspots Provisionally Accepted
Alessandro Mura1*
Francesca Zambon1
Federico Tosi1
Rosaly M. Lopes2
Julie Rathbun3
Madeline Pettine4
Alberto Adriani1
Francesca Altieri1
Mauro Ciarniello1
Andrea Cicchetti1
Gianrico Filacchione1
Davide Grassi1
Raffaella Noschese1
Alessandra Migliorini1, 5
Giuseppe Piccioni1
Christina Plainaki6
Roberto Sordini1
Giuseppe Sindoni6
Diego Turrini1
- 1Institute for Space Astrophysics and Planetology (INAF), Italy
- 2NASA Jet Propulsion Laboratory (JPL), United States
- 3Planetary Science Institute, United States
- 4Cornell University, United States
- 5National Institute of Astrophysics (INAF), Italy
- 6Italian Space Agency (ASI), Italy
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 two 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. Key points: • New photometric model for the dayside reflected sunlight and for the hotspot emission angle dependence • Improved resolution mapping of hotspots • Characterization of Io's hotspot temporal variability: low latitude hotspots have more intense temporal variability
Keywords: io, Galilean moons of Jupiter, Volcanism, infrared - IR, Juno
Received: 12 Jan 2024;
Accepted: 26 Mar 2024.
Copyright: © 2024 Mura, Zambon, Tosi, Lopes, Rathbun, Pettine, Adriani, Altieri, Ciarniello, Cicchetti, Filacchione, Grassi, Noschese, Migliorini, Piccioni, Plainaki, Sordini, Sindoni and Turrini. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Alessandro Mura, Institute for Space Astrophysics and Planetology (INAF), Rome, Lazio, Italy