September 4th, 2011

Saturn's rings

Astro-Porn of the Day: Saturn is gorgeous.

The Cassini spacecraft has been working Saturn for a while, but WOW has it ever sent us a couple of amazing shots lately! First up, check out this AMAZING shot of Saturn eclipsing the Sun:


Click the image to see the APOD page.

In 2006, Cassini spent about 12 hours in the giant planet's shadow looking toward the eclipsed Sun and photographed many wonders: The night side of Saturn is lit by light reflected from its own majestic ring system. Normally, the rings appear dark when silhouetted against Saturn, but bright when viewed away from Saturn, scattering sunlight in this exaggerated color image. Saturn's rings light up so much that scientists even discovered new rings! Particularly nice is Saturn's E ring, created by the newly discovered ice-fountains of the moon Enceladus, the outermost ring visible. Far in the distance, at the left, just above the bright main rings, is the "pale blue dot" (thanks, Carl Sagan) of Earth.

Next up is a current photo of Saturn displaying its HUGE storm, 8 times the surface area of Earth!


Click the image to see NASA's Saturn-JPL page.

Cassini first detected the storm on December 5, 2010, and it has been raging ever since at approximately 35° north latitude. Cassini photos show the storm wrapping around the entire planet, covering approximately 2 billion square miles (4 billion square kilometers).

The storm is about 500 times larger than the biggest storms we've previously detected. Scientists studied the sounds of the new storm's lightning strikes and analyzed images taken between December 2010 and February 2011 and learned that lightning flashed more than 10 times per second. As you might imagine, the storm is also a prodigious source of radio noise, so if you have a radio telescope now's the time to observe this active world. The lightning is produced in the water clouds, where falling rain and hail generate electricity. The mystery is why Saturn stores energy for decades and releases it all at once.

"Cassini shows us that Saturn is bipolar," said Andrew Ingersoll, Cassini imaging team member. "Saturn is not like Earth and Jupiter, where storms are fairly frequent. Weather on Saturn appears to hum along placidly for years and then erupt violently. I'm excited we saw weather so spectacular on our watch."

Go Saturn go! Too bad it's not in great viewing position right now....

Chris