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Radar Map of Buried Mars Layers Confirms Climate Cycles
Matt_dk writes "A radar instrument on the Mars Reconnaissance Orbiter has essentially looked below the surface of the Red Planet's north-polar ice cap, and found data to confirm theoretical models of Martian climate swings during the past few million years. The new, three-dimensional map using 358 radar observations provides a cross-sectional view of the north-polar layered deposits. 'The radar has been giving us spectacular results,' said Jeffrey Plaut of JPL, a member of the science team for the Shallow Radar instrument. 'We have mapped continuous underground layers in three dimensions across a vast area.'"
The newspeak term for that now is "global climate change".
A re-education officer will be along shortly to your location.
Actually, that term was widely held in contempt by the scientific community until it was noted that the term "global warming" actually confuses the issue because climate change doesn't evenly modify the temperature of our climate. In fact, some areas of the globe have cooled of late, but that has little bearing on the global mean temperatures, nor on the localized warming in key areas such as the Arctic. So, much as you may not like the political origins of the term, there's a reason that the media AND the scientific community is using it so widely, now.
While these results are cool, the obliquity cycle was confirmed in 2002, in a paper in Nature, Orbital forcing of the martian polar layered deposits by Jacques Laskar et al., They used pictures of the layering at the edge of the polar caps, not radar, but its basically the same idea, and they showed good correlation with recent obliquity cycles.
Again, it's cool to see these layers throughout the caps, but I don't think that anyone has doubted the connection with the obliquity / insolation cycles for a while.
No true believers are required.
Unlike the Earth (which has a big Moon to anchor things), Mars has huge variations in insolation due to its obliquity and eccentricity cycles. These oscillations drive large variations in climate, which causes the cool layering in the Martian Polar Caps - the so called North Polar Layered Deposits. There are lots of cool pictures of these layers.
While it is true that both the Earth and Mars would exhibit climate changes if the solar luminosity changed, so far I have not heard of any evidence requiring this from Mars. Mars's internal and orbital dynamics are quite enough to keep the climate modelers busy.