Jupiter's moon Io saw three massive volcanic eruptions within a two-week period last August. This August 29, 2013, outburst on Io was among the largest ever observed on the most volcanically active body in the solar system. The infrared was image taken by Gemini North telescope, courtesy of Katherine de Kleer, UC Berkeley.
Image credit: NSF/NASA/JPL-Caltech//UC Berkeley/Gemini Observatory
Note: For more information, see PIA18656: Eruptions on Io and A Hellacious Two Weeks on Jupiter's Moon Io.