PASADENA, Calif., Sept. 23 (UPI) — NASA says new imaging of the martian north-polar ice layers is consistent with theoretical models of Martian climate swings during the past few million years.
Space agency scientists said the alignment of the layering patterns imaged by the Mars Reconnaissance Orbiter with the modeled climate cycles provides insight about how the layers accumulated.
NASA said the ice-rich, layered deposits cover an area one-third larger than Texas and form a stack up to 1.2 miles thick atop a basal deposit with additional ice.
“Contrast in electrical properties between layers is what provides the reflectivity we observe with the radar,” said Nathaniel Putzig of the Southwest Research Institute in Boulder, Colo., a member of the orbiter science team. “The pattern of reflectivity tells us about the pattern of material variations within the layers.
“We’re not doing the climate modeling here; we are comparing others’ modeling results to what we observe with the radar, and using that comparison to constrain the possible explanations for how the layers form,” Putzig said.
He and nine co-authors report the findings from 358 radar observations in a paper accepted for publication by the journal Icarus and currently available online.
Copyright 2009 by United Press International