During the Q-and-A following a seminar someone (not me) commented that they recently heard that the supposed hydraulic erosion features on Mars were actually caused by CO2. The speaker responded by saying these Martian surface features were more easily explained as being caused by water erosion. However he then said that the competing erosion theories of water versus CO2 were "testable" and eventually one theory would win out. This same speaker earlier expressed vexation at the inability to find carbonates on Mars after many repeated attempts by different spacecraft. He mentioned that an orbiter will be sent to Mars in 2005 with a high resolution instrument to once again search for carbonates.

I was "good" and kept my mouth shut. I didn't mention that this "testable theory" had indeed been tested by the lack of carbonates on Mars. I walked out of the seminar feeling rather depressed thinking to myself that we are lemmings heading towards the cliff.

Gary