* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Prometheus


L

Posts: 131433
Date:
RE: Prometheus
Permalink  
 


A shepherd moon can do more to define ring structures than just keep the flock of particles in line, as Cassini spacecraft images such as this have shown.
Prometheus (102 kilometres across) is seen here with two long streamers of material that it has pulled out of the F ring. When Prometheus comes close to the F ring in its orbit, the moon's gravity tugs on the ring particles. The disturbed particles, now pulled into orbits slightly closer to Saturn and therefore faster, shear out during successive orbits, creating the long and delicate streamers seen here.

PIA08303b
Expand (117kb, 1024 x 1004)
Credit NASA

This view looks toward the unlit side of the rings from about 31 degrees above the ringplane.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 29, 2006 at a distance of approximately 1.7 million kilometres from Prometheus and at a Sun-Prometheus-spacecraft, or phase, angle of 160 degrees. Image scale is 10 kilometres per pixel.

__________________


L

Posts: 131433
Date:
Permalink  
 

Prometheus zooms across the Cassini spacecraft's field of view, attended by faint streamers and deep gores in Saturn's F ring. This movie sequence of five images shows the F ring shepherd moon shaping the ring's inner edge.


GIF animation (.2 MB)
Credit: NASA/JPL/Space Science Institute

Note that the faint ringlet coincident with the orbit of Prometheus (102 kilometres across) decreases sharply in brightness behind the moon in its path. The normally twisted-looking F ring core is overexposed in the images, causing its appearance to be more uniform than it usually is.
The images were taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 11, 2006, at a distance of approximately 2.2 million kilometres from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 162 degrees. Image scale is 13 kilometres per pixel.

__________________


L

Posts: 131433
Date:
Permalink  
 

This image shows Prometheus (left) and Pandora (right), with the icy ring particles, that makeup the F ring, between them.
Pandora is exterior to the ring, and closer to the Cassini spacecraft here. Each of the shepherd satellites has an unusual shape, with a few craters clearly visible.


Expand (28kb, 1022 x 932)

The effect of Prometheus on the F ring is visible as it pulls material out of the ring when it is farthest from Saturn in its orbit.
The image was taken in polarised green light with the Cassini spacecraft narrow-angle camera on October 29, 2005, at a distance of approximately 459,000 kilometres from Pandora and 483,500 kilometres from Prometheus.
The image scale is 3 kilometres per pixel on Pandora and 3 kilometres per pixel on Prometheus. The view was acquired from about a third of a degree below the ringplane.

__________________


L

Posts: 131433
Date:
Permalink  
 

Saturn's shepherd moon Prometheus reveals its elongated, irregular form to Cassini in this image. The moon's long axis points toward Saturn. Prometheus is 102 kilometres across.



This view shows the southern part of the moon's anti-Saturn side (the face that always points away from Saturn).

The image was taken in visible red light with the Cassini spacecraft narrow-angle camera on June 7, 2005, at a distance of approximately 438,000 kilometres from Prometheus.
Resolution in the original image was 3 kilometres per pixel.
The image has been contrast-enhanced and magnified by a factor of two to aid visibility.



__________________


L

Posts: 131433
Date:
Permalink  
 

This image was taken by the Cassini spacecraft on July 02, 2005, and received on Earth July 02, 2005.


Expand

The camera was pointing toward Prometheus that was approximately 2,130,404 kilometres away.
The image was taken using the CL1 and CL2 filters.

__________________
«First  <  1 2 3 | Page of 3  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard