Robert, this is interesting. I never thought about this. Polar satellites can be explained by GC. That's good news. Thanks, Gary Shelton > Polar orbits won't distinguish HC from GC. > HC explains the advance in longitude with each orbit as the rotation of the > Earth beneath the polsat. Seen from earth the polsat passes overhead every > 24 hours. > GC can explain the advance in longitude with each orbit as the rotation of > the polsat in response to the plenum's (local) rotation. > > Robert > -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 266.2.0 - Release Date: 2/21/05