CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Sector 6

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Common Questions
stmmr      
04-13-2009  10:14:52

04/13/2009

am not clear how Cassini’s ‘..degrees above the ring-plane’ or ‘phase, angle of … degrees’ and the ‘distance of …km from Saturn’ or the ‘image scale is … km per pixel’ etc.. relate to what I am interested in- that’s the sight-angle of Camera to a Star’s-image on A or B ring & Camera’s distance from the image’ (see my Sketch I sent you before- please note the tilt at 26.73 degrees was incorrectly shown…).



I am sure I can figure that out if I know where to look for a description of the terms ‘above ring-plane’, below ring-plane’, ‘lit side’, ‘un-illuminated side’, ‘phase, angle’ and the distance from Saturn etc… along with a 3-D diagram which shows the orbit of Cassini around Saturn.



I can’t tell (from these Photos I sent you) whether the Camera was trailing Saturn’s Orbit when these Photos were taken or was it inside (between Sun-Saturn) or outside of Saturn’s orbit in Sun-Saturn line at a specific distance above Sun-Saturn plane ?



The companion-Sun I am interested to see (or its image) can be seen ONLY if Camera is positioned close to Saturn’s magnetic-North pole and look down towards our-Sun at an angle of Approx. 87 degrees 30 minutes (to the Sun-Saturn line…).



I understand in August 2009 Saturn will be at the Equinox- that means it is very close to Equinox at this time. So, now or during the next few-months if we can position the Camera near (or close) on top of Saturn’s magnetic-North (or South-pole) and sight its view at about 87.5 degrees (+ or – a degree) below Sun-Saturn line we should be able to spot our companion-Sun (at a specific-distance below our-Sun) and we can catch its image on Saturn’s ring (B or A).



Can we take a shot in this direction any time soon ?



Please advice Who should I contact to get this done !



Mikki
stmmr      
04-12-2009  07:34:59

04/12/2009



Please tell me where can I find a diagram to visually find an answer to:



(1) What the statements below mean (visually) with respect to Saturn & Sun-Saturn plane or line? Or

(2) Where is the Camera location (distance & sight-angle) with respect to Saturn or Star or Sun-Saturn line ? And

(3) Where is Saturn in its Orbit when these Photos were taken (or how far from Aphelion or how close to Equinox….)?

(4) What is 58 degrees above ringplane & phase angle of 69 degrees- how do these angles relate to one another?

(5) How to use Image scale 54 km per pixel or 3 km per pixel… and why so much scale difference ?

(6) What is sunlit side … or 19 degrees below ringplane…? What is the phase-angle for this ?



A. “The view, which looks toward the unilluminated side of the rings from about 58 degrees above the ringplane, was obtained at a distance of approximately 825,000 kilometers (513,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 69 degrees. Image scale is 54 kilometers (34 miles) per pixel.”



B. “The views were acquired about half an hour apart as Cassini looked toward the unlit side of the rings from about 33 degrees above the ringplane.

The images were taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 26, 2006 at a distance of approximately 515,000 kilometers (320,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 102 degrees. Image scale is about 3 kilometers (2 miles) per pixel.”



C. “This view looks toward the unlit side of the rings from about 35 degrees above the ringplane. The star’s image is partly saturated, causing the vertical lines that extend up and down.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 26, 2006 at a distance of approximately 543,000 kilometers (338,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 106 degrees. Image scale is about 3 kilometers (2 miles) per pixel.”



D. “This view looks toward the sunlit side of the outer A ring (just interior to the Encke Gap) from about 19 degrees below the ringplane. Bright Aldebaran is over exposed, creating thin vertical lines on its image.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 9, 2006 at a distance of approximately 358,000 kilometers (223,000 miles) from Saturn. Image scale on the sky at the distance of Saturn is 2 kilometers (1 mile) per pixel.”



Thank you.



Mikki