* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Solar System -> Dione
Post Info TOPIC: Dione
Blobrana


L

Posts: 131433
Date:
RE: Dione
Permalink  
 

This map of the surface of Saturn's moon Dione illustrates the regions that will be imaged by Cassini during the spacecraft's very close flyby of the moon on October 11, 2005.
At closest approach, the spacecraft is expected to pass approximately 500 kilometres above the moon's surface.
The coloured lines delineate the regions that will be imaged at differing resolutions, listed in the legend at the bottom.


Expand (133kb, 1263 x 892)
Credit Nasa

Imaging scientists expect the Dione encounter to be one of the highlights of Cassini's mission. In terms of planning, this particular flyby is perhaps the most sophisticated yet undertaken by the Cassini imaging team. The timing of the imaging sequence has been optimized to within seconds, relative to the spacecraft's pointing during the encounter.
As Cassini approaches Dione, the cameras will capture regional-scale, medium resolution mosaics, with some coverage of the moon's relatively poorly imaged leading hemisphere (the region centred on 90 degrees longitude).
Planned inbound coverage also includes high-resolution images of the South Pole and the well-known streaked terrain on Dione's trailing hemisphere. The previous flyby showed the markings to be an elaborate system of braided tectonic fractures.

During the outbound portion of the flyby, Cassini will image a crescent Dione as the moon recedes into the distance. While staring at the moon's dark side, Cassini will take images using long exposure times, in order to see terrain that is dimly illuminated by reflected light from Saturn. Such a technique was successfully employed during the New Year's Eve 2004 encounter with Iapetus.
This map was made from images obtained by both the Cassini and Voyager spacecraft.
Cassini previously flew past Dione at a distance of approximately 72,100 kilometres on Dec. 14, 2004.

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Dione's southern polar region contains fractures whose softened appearance suggests that they have different ages than the bright braided fractures seen in the image to the north. This region is also notably brighter than the near equatorial terrain at the top of the image.


Expand (68kb, 896 x 910)

At centre, several of the bright, radial streaks mark a feature named Cassandra, which may be a rayed crater or a tectonic feature.
This view of Dione (1,118 kilometres across) captures high southern latitudes on the moon's trailing hemisphere.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 1, 2005, at a distance of approximately 269,000 kilometres from Dione and at a Sun-Dione-spacecraft, or phase, angle of 41 degrees.
Image scale is 2 kilometres per pixel.


__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

This image was taken on August 01, 2005 and received on Earth August 02, 2005 by the Cassini spacecraft. The camera was pointing toward Dione that was approximately 243,875 kilometres away.
The image was taken using the CL1 and IR3 filters.


Expand

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

This image was taken by the Cassini spacecraft on June 23, 2005 and received on Earth June 23, 2005.


Expand

The camera was pointing toward Dione that was approximately 1,846,079 kilometres away. The image was taken using the CL1 and CL2 filters.



__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

This unmagnified view of Saturn's moon Dione shows the moon's bright, wispy terrain, along with several large impact craters. Two of the craters have central peaks. Dione is 1,118 kilometres across.



North on Dione is up.
This view shows principally the anti-Saturn hemisphere on Dione.
It is clear why low-resolution Voyager spacecraft images gave the impression that the Dionian wispy terrain might be bright ice deposits. High-resolution Cassini images have shown these to be complex systems of braided tectonic fractures.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 25, 2005, at a distance of approximately 2.8 million kilometres from Dione and at a Sun-Dione-spacecraft, or phase, angle of 60 degrees.
The image scale is 17 kilometres per pixel.



__________________
«First  <  1 … 6 7 8 | Page of 8  sorted by
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Solar System -> Dione


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard