1.   Earth has an actively convecting dense metallic core that produces and sustains a strong magnetic field.

2.   At even greater depths, the rock may give way to a metallic core.

3.   Different instruments will search for evidence of a metallic core, the presence of seismic activity and a magnetic field.

4.   Instruments aboard the Pathfinder station have detected evidence of a magnetic field generated within the planet, and signs that Mars contains a central metallic core.

5.   The implication is that Ganymede has a molten metallic core.

6.   The metallic core of the body is too far from Galileo to produce magnetic fields the satellite could detect, Schubert said.

7.   --The presence of metallic cores inside Io, Ganymede and Europa, and the curious lack of a similar core inside Callisto.

8.   It has already allowed them to establish beyond a doubt that Io is made of a huge metallic core.