This is an image of "puddle-like" flows of Europa taken by the Galileo spacecraft. This image is called "the mitten".
Click on image for full size
The picture seems to show the presence of a "puddle" which has seemingly wiped out the surface nearby. Scientists cannot prove that this feature is really the remnants of a puddle, but such a patch probably involves a local pocket of water which refroze on the surface.
This feature suggests a third process, one which scientists call icy-volcanism. In this case, even though a volcanic cone is not formed, a liquid comes out of the ground and flows on the surface. That is why this feature is called icy-volcanism.
You may leave the tour and read more about terrestrial volcanism and how volcanic cones are formed on Earth using the link at the bottom of the page.
This is page 9 of 20
Shop Windows to the Universe Science Store!
Our online store
includes fun classroom activities
for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist
are also full of classroom activities on different topics in Earth and space science!