OFFICE OF PUBLIC INFORMATION
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (2l3) 354-5011
 
PHOTO CAPTION                                      Voyager 2-30
                                                   P-21760C
                                                   July 10, 1979
 
This color image of the Jovian moon Europa was acquired by
Voyager 2 during its close encounter on Monday morning, July 9.
Europa, the size of our moon, is thought to have a crust of ice
perhaps 100 kilometers thick which overlies the silicate crust.
The complex array of streaks indicate that the crust has been
fractured and filled by materials from the interior. The lack
of relief, any visible mountains or craters, on its bright limb
is consistent with a thick crust. In contrast to its icy
neighbors, Ganymede and Callisto, Europa has very few impact
craters. One possible candidate is the small feature near the
center of this image with radiating rays and a bright circular
interior. The relative absence of features and low topography
suggests the crust is young and warm a few kilometers below the
surface. The tidal heating process suggested for Io also may
be heating Europa's interior at a lower rate.