Ghostly 'Spokes' Puff Out From Saturn's Ring's (w/ Video)

Nov 16, 2009
Massive, bright clouds of tiny ice particles hover above the darkened rings of Saturn in an image captured by the Cassini spacecraft on Sept. 22, 2009, around the time of Saturn's equinox. Image credit: NASA/JPL/Space Science Institute

(PhysOrg.com) -- Massive, bright clouds of tiny ice particles hover above the darkened rings of Saturn in an image captured by the Cassini spacecraft on Sept. 22, 2009, around the time of Saturn's equinox.

During this period, sunlight hits the rings edge-on and shines directly over the equator. The levitating icy particle clouds, which are known as "spokes" and are as wide as 10,000 kilometers (6,000 miles), appear particularly dramatic because of the unique lighting geometry of the equinox period.

This video is not supported by your browser at this time.
A movie of spokes dancing around the rings in 2008.

The particles that make up spokes levitate above the ring plane when they acquire an electrostatic charge, the way static electricity on Earth can raise the hair on your arms. The spoke particles appear to acquire more charge during dim conditions and, during equinox, the bulk of the rings are in shadow. That angle of also brightens features that stick out of the ring plane.

Saturn's exact equinox was Aug. 11, 2009, but there were extreme lighting conditions a few weeks before and after that date. Cassini's wide-angle camera captured this image six weeks later, when the spacecraft was about 1.3 million kilometers (808,000 miles) away from . The spokes appear in Saturn's B ring. Scientists are not yet sure how high these spokes hover above the ring plane. The bright dot on the left side of the image is Saturn's moon Janus.

Spokes in Saturn's rings were first discovered in the late 1980s by NASA's Voyager spacecraft. The features disappeared from view between 1998 and 2005, likely because of the angle of sunlight on the rings. To learn more about spokes, click here.

Provided by JPL/ (news : web)

Explore further: Red moon at night; stargazer's delight

add to favorites email to friend print save as pdf

Related Stories

Cassini Spacecraft Witnesses Saturn's Blues

Feb 09, 2005

Colorful new images from the Cassini spacecraft show that Saturn's northern hemisphere has a case of the blues. In the first image, the icy moon Mimas is set against a dazzling and dramatic portrait of Saturn's ...

Ghostly spokes in Saturn's rings spotted by Cassini

Sep 16, 2005

Delighted scientists on the Cassini imaging team will be breaking out the champagne in celebration of the first Cassini sighting of spokes, the ghostly radial markings discovered in Saturn's rings by NASA's ...

A long night falls over Saturn's rings

Oct 24, 2009

As Saturn's rings orbit the planet, a section is typically in the planet's shadow, experiencing a brief night lasting from 6 to 14 hours. However, once approximately every 15 years, night falls over the entire ...

Recommended for you

Red moon at night; stargazer's delight

2 hours ago

Monday night's lunar eclipse proved just as delightful as expected to those able to view it. On the East Coast, cloudy skies may have gotten in the way, but at the National Science Foundation's National Optical ...

Meteorites yield clues to Martian early atmosphere

4 hours ago

(Phys.org) —Geologists who analyzed 40 meteorites that fell to Earth from Mars unlocked secrets of the Martian atmosphere hidden in the chemical signatures of these ancient rocks. Their study, published ...

Let's put a sailboat on Titan

7 hours ago

The large moons orbiting the gas giants in our solar system have been getting increasing attention in recent years. Titan, Saturn's largest moon, is the only natural satellite known to house a thick atmosphere. ...

Image: Rosetta's Philae lander snaps a selfie

7 hours ago

Philae is awake… and taking pictures! This image, acquired last night with the lander's CIVA (Comet nucleus Infrared and Visible Analyzer) instrument, shows the left and right solar panels of ESA's well-traveled ...

User comments : 0

More news stories

Meteorites yield clues to Martian early atmosphere

(Phys.org) —Geologists who analyzed 40 meteorites that fell to Earth from Mars unlocked secrets of the Martian atmosphere hidden in the chemical signatures of these ancient rocks. Their study, published ...

Red moon at night; stargazer's delight

Monday night's lunar eclipse proved just as delightful as expected to those able to view it. On the East Coast, cloudy skies may have gotten in the way, but at the National Science Foundation's National Optical ...

Researchers see hospitalization records as additional tool

Comparing hospitalization records with data reported to local boards of health presents a more accurate way to monitor how well communities track disease outbreaks, according to a paper published April 16 in the journal PLOS ON ...

Ebola virus in Africa outbreak is a new strain

Scientists say that the Ebola (ee-BOH'-lah) virus that has killed scores of people this year in Guinea (GIH'-nee) is a new strain. That means it did not spread there from outbreaks in some other African nations.