Mars Polar Cap Mystery Solved

Matt_dk writes "Scientists are now able to explain why Mars' residual southern ice cap is misplaced, thanks to data from ESA's Mars Express spacecraft (the same probe running the 'Mars Webcam'). It turns out the martian weather system is to blame. And so is the largest impact crater on Mars — even though it is nowhere near the south pole. Like Earth, Mars has frozen polar caps, but unlike Earth, these caps are made of carbon dioxide ice as well as water ice. During the southern hemisphere's summer, much of the ice cap sublimates, a process in which the ice turns straight back into gas, leaving behind what is known as the residual polar cap. The mystery was that while the winter cap is symmetrical about the south pole, the residual cap was offset, and scientists couldn't figure out why."

Comments

Alien planet

[Dan East]

It seems absurdly simple, but it is quite foreign to meteorology on our planet to have an impact crater affecting the global climate and weather patterns. That will be just another of those little things that will give future astronauts the "this isn't Kansas anymore" feeling as they live on another planet.

Two mysteries linked by Rossby waves

[exp(pi*sqrt(163))]

The important phenomenon at work here is that of Rossby waves. It's interesting that this type of polar standing wave may also be implicated in the famous Saturnian hexagon.