Mt. Vernon Register-News

Community News Network

February 20, 2013

Saturn's kinky rings explained

The first time you see Saturn's rings through a telescope is amazing. It can change your life — literally, as it did for me when I was a wee lad.

The rings are shocking through a big telescope. Even through a small one you can see them clearly, and with a big one you can start to see some details, like the big Cassini Division, a dark gap slicing the main ring system in two.

But there's nothing like being there. The Cassini spacecraft (named after the Italian astronomer Giovanni Cassini, who discovered his eponymous division) has been orbiting Saturn since 2004. A masterwork of engineering, Cassini has returned thousands upon thousands of incredible images, showing amazing details in the rings.

On Dec. 25, 2012, from a distance of 1.1 million kilometers (680,000 miles), it took this phenomenal shot of Saturn's outer rings [see photo].

Saturn is off the frame to the upper left in this picture. Cassini was just over the plane of the rings, looking at them from a shallow angle. The sun is shining down on them, so they look very bright.

The main A ring is to the upper left, and you can see the Keeler gap, a narrow (40 km/25 mile) empty region in the rings, where the ice particles that make up the rings have been swept clear by the gravity of the tiny moon Daphnis.

But the star of this show is the weird F ring (the rings were named in order of discovery, not distance from Saturn). To give you a sense of scale, the division between the A and F rings is about 3,000 km (1,800 miles), roughly the distance from New York City to Denver, Colo.

The ring is narrow, and that's no accident. Orbiting just inside and outside of it are two very small moons named Prometheus and Pandora, and they act as shepherds, constraining the ice particles into that narrow strand. Due to the vagaries of orbital mechanics, most of the particles that stray outward or inward from the ring are gently nudged back into it by the moons' gravity.

Text Only
Community News Network
  • A 'wearable robot' helps her walk again

    Science is about facts, numbers, laws and formulas. To be really good at it, you need to spend a lot of time in school. But science is also about something more: dreaming big and helping people.

    April 23, 2014

  • Cuba is running out of condoms

    The newest item on Cuba's list of dwindling commodities is condoms, which are now reportedly in short supply. In response, the Cuban government has approved the sale of expired condoms.

    April 23, 2014

  • Screen Shot 2014-04-22 at 4.42.47 PM.png VIDEO: Leopard attacks crowd in India

    A leopard caused panic in the city of Chandrapur when it sprung from the roof of a house and charged at rescue workers.

    April 22, 2014 1 Photo

  • In cuffs... 'Warlock' in West Virginia accused of sexual assault

    Police in West Virginia say a man claiming to be a “warlock” used promises of magical spells to lure children into committing sexual acts with him.

    April 22, 2014 1 Photo

  • McCain 1 House Republicans are more active on Twitter than Democrats

    Your representative in the House is almost certainly on Twitter. Your senator definitely is. But how are they using the social network? Are Democrats more active than Republicans, or vice versa? Who has the most followers on the Hill?

    April 22, 2014 1 Photo

  • Do White Castle prices tell us anything about the minimum wage?

    The paper looked at how many delicious steamed sliders the minimum wage has been able to purchase over time. The point is that as it notes, in 1981, the $3.35 minimum could buy a whole dozen. Today, at $7.25, it could purchase just 10.

    April 21, 2014

  • VIDEO: Moose charges snowmobile, flees after warning shot

    While snowmobiling in New England, Bob and Janis Powell of Maine were charged by a moose and caught the entire attack on camera.

    April 21, 2014

  • Why do wolves howl?

    Of all the myths that dog the wolf, none is more widely accepted than the idea that wolves howl at the moon. Images of wolves with their heads upturned, singing at the night sky, are as unquestioned as a goldfish's three-second memory or a dog's color-blindness (both also myths).

    April 18, 2014

  • quake.jpg Pennsylvania won’t take action following Ohio ruling on quakes, fracking

    Pennsylvania officials plan no action despite new Ohio rules on drilling that affect a seismically active area near the state line.

    April 18, 2014 1 Photo

  • The case for separate beds

    The other night I slept on a twin bed in the guest room of the house I share with my husband and our two kids.
    It was the best night's sleep I've had in years.

    April 17, 2014

Twitter Updates
Facebook
Stocks