Suggestion
I've also had lengthy discussions with Nick both in this forum and in person concerning Mars. If you wish to pursue this thread, I suggest starting a new discussion at the top of this page and then draw in Nick. This thread is almost off the front page and will effectively die once it goes onto the next page. If I can add something then I will. However Nick's knowledge about Mars is of such a high level that when he's carry on a discussion, I prefer to stand in the audience, cheer and let the master do his thing.
Gary