cosmoworld7: Go BKMP...I loved Carl Sagans segments on space etc. He once said of Kepler on one of his broadcasts...a physical force moves the planets in their orbits. Kepler was the first to combine a bold imagination with precise measurements. To step out into the cosmos. It changed everything. This fusion of facts with dreams opened the way to the stars. He preferred the hard truth to his dearest illusions. That is the heart of science. Go BKMP....