Wednesday, December 15, 2010

Putting the G in AGU, Part 1

By Alaina G. Levine

There may be a ring around the Earth, according to a consultant whose poster was presented at the American Geophysical Union (AGU) Annual Fall Meeting this week in San Francisco. And that ring might be affecting climate change.

But before you say “du’oh-f course!” to the idea that there’s a donut of particles circulating around the globe, know this: just as is the case with most controversial ideas in science, people are just about willing to come to blu’ows over it.

And so it was that while meandering through the poster fields of AGU I ran across the consultant’s poster and witnessed two scientists with elevated voices explaining to her that there was no way that there was a ring, akin to one of Saturn’s, ‘round the earth, with nobody knowin’ nothin’ ‘bout it before.

I asked one of the screaming nerds about the research before me and he suggested that she probably saw an anomaly in the climate data and was arguing a ring was the cause. But a ring that would be massive enough to contribute to climate change would have been observable, and yet, for some reason nobody seemed to notice it. Perhaps it was because we were so focused in on ET being found in a California lake that we missed all the crap floating mere miles into space.

No biggie. There was much more to see, do, and hear at AGU. Posters at the AGU Meeting play a big role, as big as talks, said one source. So I skipped over to another poster on the Planetary Sciences aisle and found that there is an elementary proposal in the works, as part of the Planetary Sciences Decadal Survey, to build and launch a Saturn Ring Observer.

As Matthew S. Tiscareno, a grad student at Cornell and one of the authors, explained it, the Observer would sit 3 km above Saturn’s rings and monitor how particles in the rings interact with each other. The particles, unbeknownst to the casual bystander, are constantly bumping into each other and clumping together. The rings move at a velocity of 10 km/sec, but the individual particles move at a relative velocity much slower – As Tiscareno, et al, notes in their poster, “Typical particle sizes in the rings of Saturn and Uranus are a few meters. Indirect evidence indicates that the vertical thickness of the rings is as little as 5 to 10 m which implies a velocity dispersion of only a few mm/sec.”

A Saturn Ring Observer would be the very first in situ spacecraft to directly study Saturn’s jewelry and help us better understand its microphysical reactions. Stay tuned…

1 comment:

  1. Posters at the AGU meetings do play a big role it seems from what you have said and in this case even taught specialists in their field something new!

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