Lava Fountains
Lava fountains produce a spectacular show on Earth and they have also been observed on Io on the Tvashtar region. In this image, a fissure eruption ejected molten material more than 1.5 kilometers high (1 mile). Estimates of the temperature of the fountain range from 1,000 K (1,300 Fahrenheit) to 1,600 K (2,400 Fahrenheit). The brightness of the fountain overloaded the camera's detector and caused it to show up as a white blur in the image.
The image also shows a the first close-up views of a large chain of calderas on Io. The calderas in this region dwarf other calderas in the solar system with dimensions of 290 km by 100 km (180 miles by 60 miles). This is larger than the largest caldera on Earth.
This
color image is an interpretive drawing by Galileo scientists
which shows the same area in the photo above. The bright
streak is a series of lava fountains. Lava flows are also
visible on the floors of the caldera. The darkest flows are
the most recent.
Photoglossary