1.   Spacecraft sent to Venus and Mars have produced better topographical maps of those worlds than exist for Earth.

2.   The Earth is not alone in such churning, as was driven home last week as the Galileo spacecraft sent back its first measurements and images of Ganymede.

3.   The main spacecraft then will send itself on a path to burn up over the Pacific Ocean.

4.   Spacecraft sends back evidence of huge Mars flood.