Saturn's Spokes: Lost and Found

  title={Saturn's Spokes: Lost and Found},
  author={Colin J. Mitchell and Mih{\'a}ly Hor{\'a}nyi and O. Havnes and Carolyn C. Porco},
  pages={1587 - 1589}
The spokes are intermittently appearing radial markings in Saturn's B ring that are believed to form when micrometer-sized dust particles are levitated above the ring by electrostatic forces. First observed by the Voyagers, the spokes disappeared from October 1998 until September 2005, when the Cassini spacecraft saw them reappear. The trajectories of the charged dust particles comprising the spokes depend critically on the background plasma density above the rings, which is a function of the… 
Spokes in Saturn's B Ring: Could Lightning be the Cause?
Spokes are narrow markings across Saturn's B ring, most likely caused by a cloud of micrometer-sized particles intermittently lofted from the larger boulders in the ring. They were observed by the
The Behavior of Spokes in Saturn's B Ring
Formation of Saturn's ring spokes by lightning‐induced electron beams
Spokes are near‐linear markings sometimes visible on Saturn's rings. They are widely accepted as being electrostatically‐levitated sheets of ∼0.6 micron‐radius charged grains. Previously‐suggested
Statistical Perspectives on the Study of the Ring Spokes of Saturn
At the beginning of the Cassini Extended mission, the VIMS spectrometer was able to collect the first images of spokes on the Saturn rings at wavelengths longer than 1.1 μm ([1]). Previous
First ground observations of Saturn's spokes around 2009 equinox
Since 1980, only spacecraft or space telescope have been able to image spokes (intermittently appearing radial or elongated dark markings in Saturn’s B-ring) around the planet equinoxes. Amateur
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On 2008, July, the Cassini/VIMS spectrometer detected spokes on the Saturn's B ring for the first time. These are the first measurements of the complete reflectance spectrum of the spokes in a wide
Chapter 16 Diffuse Rings
In order to give context to Cassini’s findings about Saturn’s diffuse rings, this chapter first recalls the Voyager and telescopic observations prior to 2004. Cassini has investigated these faint
The Charging of Planetary Rings
This chapter will review what is known about the charging of planetary rings, in particular the sum of the individual currents from the time-varying charge dQ/dt, of the planetary ring particle. For


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Two of the features in the Saturnian ring system recently observed by the Voyager 1 spacecraft are (a) the braiding of theF-ring and (b) the radial spokes that rotate across theB-ring. Both of these
Oxygen Ions Observed Near Saturn's A Ring
The INMS saw signatures of molecular and atomic oxygen ions and of protons, thus demonstrating the existence of an ionosphere associated with the A ring, according to the Cassini Orbiter.
A New Look at the Saturn System: The Voyager 2 Images
Within Saturn's rings, the "birth" of a spoke has been observed, and surprising azimuthal and time variability is found in the ringlet structure of the outer B ring, leading to speculations about Saturn's internal structure and about the collisional and thermal history of the rings and satellites.
Encounter with saturn: voyager 1 imaging science results.
As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies, including small inner satellites that interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system.