At the time (September 2002), the working model was that the deeply buried ruins of Cydonia were encased in an enormous block of ice that was covered with a thin layer of “poof dust,” making the ground appear opaque. Severe criticisms were immediately forthcoming, primarily arguing on two major points. First, that the THEMIS IR instrument couldn’t penetrate thousands of feet below the surface to generate a return signal to the instrument, and second that there was no evidence other than our controversial images that such a layering of ice even existed.
Dr. Phillip Christensen of ASU, principal investigator on the THEMIS device, later put the first item to rest, stating in an interview that THEMIS has been more successful at penetrating the Martian surface than even he imagined. His claims of at least “a meter” of penetration for the thermal instruments jibes well with our model of a few inches (at best) of Martian “poof dust.”
But the key to our model would be the discovery at Cydonia of significant quantities of sub-surface ice. That is no longer a problem.
Two new papers produced from results of the MRO’s ground penetrating radar data confirm that vast glaciers cover much of the mid-latitude northern hemisphere of the planet, just as Dark Mission and our own Mars Tidal Model predict. Geologist Jeffrey J. Plaut of JPL, who will be publishing results about the ice deposits in the American Geophysical Union's Geophysical Research Letters, stated in an MRO press release that most of the ice is in two latitude bands stretching from about “35 to 60 degrees in both hemispheres.” This would neatly encompass the Cydonia region, which lies at 41 degrees north latitude.
And once the infrared signal from the THEMIS instrument on Mars Odyssey got past that thin layer of obscuring dust, there is no telling how deeply it could have penetrated through the transparent block of ice.