Saturn's aurora, even better than before
Posted by Emily Lakdawalla
24-11-2009 15:35 CST
The Cassini imaging team have posted their own processed and captioned version of the Saturn's aurora movie that I posted a preview of about six weeks ago, and it was worth the wait. It turns out that the video covers an amazing 81 hours of auroral action on Saturn's night side. This version of the video has also been annotated with lines denoting Saturn's limb and latitudes 70 and 78 degrees north latitude. The auroral action occurs at a latitude of 74 degrees north latitude and extends an amazing 1,200 kilometers above Saturn's limb, making them "the tallest known 'northern lights' in the solar system,' according to the caption released with the movie. An orange color was added to the aurora in order to help differentiate it from the star-streaked background. Other processing included the removal of cosmic ray hits and hot pixels.
According to the Cassini imaging team, "These auroral displays are created by charged particles from the magnetosphere that plunge into the planet's upper atmosphere and cause it to glow. The magnetosphere is the region of electrically charged particles that are trapped in the magnetic field of the planet. The auroral curtains shown in the movie reveal the paths that these charged particles take as they flow along lines of the magnetic field between the planet's magnetosphere and ionosphere."
Credit: NASA / JPL / SSI