Bleak as it may seem, it may not take as long for the dust to settle out as many are inclined to think. “Things do mix up in the atmosphere,” reiterated Lemmon.

While the 10.8 Tau has a lot of team members concerned, Lemmon is not as concerned. “It really depends on the overall perspective. If you say optical depth was 10 or 11 or more for Opportunity and you look at how fast it decays exponentially, that projects a very bad answer in terms of how long it’s going to take. But frankly, Opportunity was sitting in the worst of it,” he said.

“Once the lifting stops and the normal circulation averages the dust out, usually on a timescale of many days to a few weeks, the Tau can go from 10 to 5 or 3 very fast,” Lemmon continued. “Then, once you’re around 3 or 4, you start going into this very slow decay. But it depends very much on exactly how much dust was picked up everywhere around Mars with this storm and we can’t measure that with what we have very accurately, so we will just have to wait and see how that plays out.”

When the storm transitions well into the decay phase, Curiosity’s measurements should help the MER team understand what’s going on at the Meridiani site as well, said Lemmon. Basically, the Tau Curiosity records at Gale Crater will likely be the Tau Opportunity will see at Meridiani Planum about a week later. “Right now, they’re just in different weather,” he said.

Figuring out what causes these dust storms to stop once they get started will go a long way to understanding how humans, as well as robots, can survive these PEDEs. The scientists studying this PEDE will be looking for more clues about the decay processes in coming days and weeks. There are plenty of good, seemingly scientifically sound theories.

Maybe these monster dust storms just run out of power. Since the radiative heat of sunlight reaching the surface of the planet is what drives these dust storms, the large planet-encircling dust storms may ultimately doom themselves.“It could be that the winds die down because once all that dust gets into the atmosphere it blocks a lot of the sunlight and there is less heating at the surface,” said Wolff, who will be working to quantify the evolution and the amount of dust in the atmosphere with imaging instruments, including TES onboard Odyssey. “Dust in the atmosphere may absorb energy and make the atmosphere warmer, but the surface gets colder, because there’s not as much sunlight getting down to the surface. At some point that lack of solar energy will cut off the ability to lift dust.”

Or, perhaps the lifting centers have lifted all the Martian dust in their paths there is to lift. “It could be there are these reservoirs of dust on the surface that are easily lofted and they kind of run out,” suggested Smith. “That could also be why we see these global scale dust storms in some years but not every Mars year, because there’s just not any more dust that can get picked up until those resources restore, and as dust falls out all over planet these reservoirs eventually build back up.”

With all the research efforts underway, this storm may offer up telling clues. With a little of the MER luck, maybe the storm will be over soon.