Saturn exposed: Los Alamos gadgets reveal secrets that 'cameras can't show'

Sue Vorenberg | The New Mexican

3/13/2008 - 3/14/08

There's a lot more to the weird, massive landscape around Saturn than a picture can reveal.

In fact, if a picture is worth 1,000 words, than data gained from a series of instruments that pick up invisible phenomenon — like the behavior of magnetic fields and the interaction of charged atoms around the planet — might be worth a trillion words.

And it's that invisible knowledge and science that give two Los Alamos National Laboratory scientists a thrill, as they study information returned from instruments designed at the lab that are flying on the National Aeronautics and Space Administration's Cassini mission.

"Normally with Saturn, people see all these great pictures in the newspapers, but they don't see the particle data," said Rob Wilson, one of the scientists. "There's a whole wealth of other science going on that's just as important, just as fascinating. Things the cameras can't show."

Recent news that Saturn's moon Rhea has a ring of dust-size particles is just one instance of that invisible data coming to light.

The instruments from Los Alamos, which measure groups of negatively and positively charged atoms called ions, were part of a suite that discovered that ring. And they're teaching scientists more about how the whole planetary system works.

"No one has actually ever seen a moon with rings before," Wilson said. "But that's just part of the picture. In the past people really didn't know what moons were, but this mission let us know they have their own magnetic fields, their own magnetospheres."

And the magnetic fields of Saturn's moons don't just sit there. They interact with the planet's magnetic field, and also with the solar wind, creating a very complex system and probably some very beautiful Saturnian versions of the Earth's northern lights, said Hazel McAndrews, another scientist.

"Everything we're finding is new," McAndrews said. "I think one of the key areas we're hoping to learn more about in coming years is how much interaction is going on between the solar wind and Saturn's magnetosphere."

On Earth, the northern lights are created when our magnetic field interacts with a phenomenon related to the sun's magnetic field — called the solar wind. In essence, Earth's magnetic field gets dragged and twisted into the solar wind, creating the streams of light in our northern sky, McAndrews said.

"So one thing that's interesting about Jupiter and Saturn is that they're so big," McAndrews said. "And what we want to learn is does a planet with such a large magnetic field of its own care that this magnetic field is coming from the sun?"

You could fit 764 Earths inside of a hollowed-out Saturn, to get some idea of the size. And that makes Saturn's magnetic field much larger than Earth's, McAndrews said.

But so far, the instruments seem to indicate that despite its size, Saturn's magnetic field also gets twisted by the solar wind, she said.

"We've looked at the magnetic boundaries, called the magnetopoles, to see if there's evidence of that ripping and twisting between the fields," McAndrews said. "And we found evidence that suggests yes, that is in fact occurring."

NASA launched its Cassini-Huygens probe in 1997, and it arrived at the Saturn system in 2004. Since then, it's been gathering data from the planet and its moons including Phoebe, Titan, Enceladus and Rhea.

When the main mission is finished, it will have conducted 74 orbits around the planet, including 44 flybys of Titan, by June 2008.

On Wednesday, it flew less than 120 miles from the surface of Enceladus, coasting through what appears to be geysers and taking samples of water-ice, dust and gas so scientists can better understand the phenomenon.

That data from that event probably won't be ready for them to look at until next week, though, the LANL scientists said.

But they're eagerly awaiting it. And every bit of information they get leads to more scientific thrills, Wilson said.

"I definitely like the outer planets," Wilson said. "They're so big, and pretty much, they're so unknown. A lot of these results, you only know by going there and measuring them. You can't see them from far away. It's fun to find things, especially when no one has been there before."

Contact Sue Vorenberg at 986-3072.