This is image shows an example of Europa "pits domes & spots". The image was taken by the Galileo spacecraft.
Click on image for full size
2.) Pits, domes, and spots were found in selected regions of Europa, such as to the right of the linea in this image. Scientists did not see these everywhere, but remember that the Galileo spacecraft did not photograph the entire surface of Europa. They may have come to be in place as a result of the rise of what is called a "diapir". A diapir is similar to a plume of material rising from a lower level to the surface which pushes out the surface and causes a bump to appear on the surface.
This is page 7 of 20
Shop Windows to the Universe Science Store!
Our online store
on science education, classroom activities in The Earth Scientist
specimens, and educational games