Io is the innermost of Jupiter's four moons that were discovered b Galileo in January 1610. Io is a bit bigger than our moon, but the most geologically active body in the solar system, according to a press release. The moon - mainly covered by sulfur and sulfur dioxide - is sprinkled with hundreds of volcanic areas.
Astronomical Journal Publication
"Spatially resolved M-band emission from Io's Loki Patera - Fizeau imaging at the 22.8 meter LBT"
Albert Conrad, Katherine de Kleer, Jarron Leisenring, Andrea La Camera, Carmelo Arcidiacono, Mario Bertero, Patrizia Boccacci, Denis Defrère, Imke de Pater, Philip Hinz, Karl-Heinz Hofmann, Martin Kürster, Julie Rathbun, Dieter Schertl, Andy Skemer, Michael Skrutskie, John Spencer, Christian Veillet, Gerd Weigelt, Charles E. Woodward
https://iopscience.iop.org/1538-3881/149/5/175/article
doi: 10.1088/0004-6256/149/5/175
