23 May 1997
Vol 276, Issue 5316

About The Cover

Cutaway view of the possible structure of Jupiter's moon Europa. The surface is a mosaic of Voyager images, and the interior characteristics are inferred from gravity-field and magnetic-field measurements by the Galileo spacecraft. A metallic core (gray) is surrounded by a mantle of rock (brown) and an outer shell of water ice (blue and white), part of which could be liquid. Relative sizes of the regions are to scale. See the related Reports on pages 1236 and 1239. [Graphics: E. De Jong and Z. Gorjian, JPL Digital Image Animation Lab