Don’t be misled by the
sheets of “flame” depicted in the above images of the
Tvashtar region of Io, Jupiter’s closest
Moon. Planetary scientists have colored in bleached-out areas on
the photographs taken by the Galileo probe, converting
the images into what they had expected to find — lava fountains.
The original image is inset in the lower right corner of the photograph. According to the release,
Yet no lava flow
ever witnessed has exhibited temperatures so high as to produce the
effect seen in the original Galileo image.
This image is actually a
processed mosaic combining images taken in the near-infrared,
clear, and violet filters. All that later analysis could determine
is that temperatures exceeded 1200 K. To place the matter in
perspective, with attention to the alternative electrical
explanation: a lightning discharge "pinches" down to a
few centimeters diameter (or possibly meters in the case of the
diffuse discharge on Io) where it meets a conducting
electrode. So if the instruments were detecting an electric
discharge any temperature reading, averaged over a much
larger region than the actual heat source, would have greatly
understated the real temperature.