Active Volcanic Plumes on Io
This color image, acquired by the Galileo spacecraft in 1997 on its ninth orbit around Jupiter, shows two volcanic plumes erupting on Io. The view also includes detailed insets of the plumes.
One plume was captured on the bright limb or edge of the moon, is 140 kilometers (86 miles) high, and was also detected by the Hubble Space Telescope. The second plume is closer to the center of the image. The reddish shadow of this airborne plume can be seen extending to the right of the eruption vent. (The vent is near the center of the bright and dark rings).
Full caption is available here. Another version of this image, with enhanced surface detail, can be found here.