Kind of on a different note, did you know that one of Jupiters moons, Io is the most volcanically active body in the solar system with over 100 active volcanoes?
Jupiter's four largest satellites, including Io, the golden ornament in front of Jupiter in this image from NASA's Cassini spacecraft, have fascinated Earthlings ever since Galileo Galilei discovered them in 1610 in one of his first astronomical uses of the telescope. This true-colour composite frame, made from narrow angle images taken on 12 December 2000, captures Io and its shadow in transit against the disk of Jupiter. The distance of the spacecraft from Jupiter was 19.5 million kilometres. The image scale is 117 kilometres per pixel. The entire body of Io, about the size of Earth's Moon, is periodically flexed as it speeds around Jupiter. As a result of its non-circular orbit, it feels the periodically changing gravitational pull of the planet. The heat arising in Io's interior from this continual flexure makes it the most volcanically active body in the solar system, with more than 100 active volcanoes. The white and reddish colors on its surface are due to the presence of different sulfurous materials. The black areas are silicate rocks.
Here's a great picture of an eruption on Io..........
This image of a plume erupting from Tvashtar, a volcano on Io was taken by the Long Range Reconnaissance Imager (LORRI) on New Horizons at 11:04 Universal Time on February 28, 2007. Five hours after the spacecraft's closest approach to Jupiter, the picture was taken from a distance of 2.5 million kilometres. The image was centred at 85 degrees west longitude, in the 11 o'clock direction near Io's north pole. The plume depicted is about 290 kilometres high. Seen at first by the Hubble Space Telescope, and then two weeks later on February 26 2007 by New Horizons itself, this image is much clearer. This is due to longer exposure; there is an excellent view of the night-side illuminated by Jupiter.
I'm still looking for more info on the big red spot!