Mark,

I'm not really surprised that Mars Odyssey detected so much ice. We've known about "splat craters" since Mariner 9. The only credible mechanism for a splat crater is lots of near surface ice.

Don't sell Nick's White Mars short. I still believe Nick is right in theorizing that many of the Martian surface features are due to carbon dioxide or carbon dioxide / water (clathrate) phase change. Mars has always been too cold to allow for liquid water to play a significant role except for transient phenomena due to an asteroid impact.

Mars has always been cold and dead but we can bring life to Mars. Due to the abundance of water, diverse minerals and a carbon dioxide atmosphere it appears that colonizing Mars is practical.

Gary