Two Full Days of Saturn’s Aurora

[n2doc]

Saturn’s aurora shimmers and shines over the course of two full days in a new movie and images from Cassini orbiter. In an ongoing study compiling thousands of these images, scientists are beginning to decipher what drives the celestial light show.

Much like Earth’s northern and southern lights, Saturn’s aurora is triggered when charged particles from solar winds are channeled toward the poles by the planet’s magnetic field. At the poles, these particles interact with charged gas or plasma in the upper atmosphere and emit light. Saturn’s aurora can also be caused by electromagnetic waves generated when its moons move through its magnetosphere.

Cassini has already delivered some gorgeous examples of these colorful curtains of light.

“But to understand the overall nature of the auroral region we need to make a huge number of observations — which can be difficult because Cassini observation time is in high demand,” said astronomer Tom Stallard of the University of Leicester in the UK in a press release.



Read More http://www.wired.com/wiredscience/2010/09/video-saturn-aurora/

http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20100923.html

[Tansy_Gold]

1. I love this stuff!

I don't always catch your posts but when I do, you never disappoint.

Thank you for putting up some of the most beautiful, most awe-inspiring photos and articles!




Tansy Gold, non-scientist fascinated by science

[deutsey]

2. I agree. Thanks!

[rayofreason]

3. Cool, but...

...the stament in the article

Saturn’s aurora is triggered when charged particles from solar winds are channeled toward the poles by the planet’s magnetic field.

is nonsense. The solar wind blows past Saturn's magnetic field, and some small fraction of the energy is captured in the Saturnian magnetosphere. That energy powers a system of electric currents, some of which close in the polar regions, but not at the poles where there is direct entry of solar wind particles (which are at most a few 10's of eV in energy). If the current densities are large enough, electric fields parallel to the magnetic field are established, and these accelerate electrons to KeV energies. It is those electrons that hit neutral atoms and cause them to emit light.

[Judi Lynn]

4. Unbearably beautiful. Thank you. n/t