The Moon Europa:
Cue Ball of the Satellites
Smoothest Body Around
Europa, pictured in the image to the right, may be
the smoothest solid body in the Solar
System. It appears to be covered with a frozen water ocean and
has very few craters. As the adjacent image indicates, it is covered with
cracks, but these seem to have little vertical relief
(Ref).
Details of the crazed cracks criss-crossing Europa's frozen surface are
apparent in this mosaic
of the Galileo spacecraft's latest images of Jupiter's ice-covered moon shown
to the left
(Ref). Here is
a
further discussion of these
Cracked Ice Plains of Europa.
History of Europa
Europa, like Io, is heated internally by the tidal tug-of-war with Jupiter, but
because Europa is further from Jupiter than Io the tidal effect is less
dramatic. In the case of Europa, the effect of the tides induced by Jupiter is
to heat the interior of Europa sufficiently to keep the surface soft. Thus, no
vertical relief features can survive for long on Europa's surface, explaining
its smooth appearance.