[math-fun] As long as we're talking astronomy
http://media.zenfs.com/en_us/News/Reuters/2012-12-19T035245Z_616564795_TM3E8... shows the ridiculously complicated illumination of Saturn's nightside by sunlight scattered off the rings, some of which is then viewed though the rings. At 4 o'clock on the limb, there is even an arc filtered through the dayside rings and then the upper atmosphere. But I don't understand: 1) Why the crisp silhouettes of the near rings against the (false color) green background seem discontinuous with the arcs outside the planet's shadow, presumably viewed by scattered, transmitted sunlight. 2) The bluish white haze extending far to the right from 5 o'clock on the limb. --rwg
On 12/29/12, Bill Gosper <billgosper@gmail.com> wrote:
1) Why the crisp silhouettes of the near rings against the (false color) green background seem discontinuous with the arcs outside the planet's shadow, presumably viewed by scattered, transmitted sunlight.
Part of that may be the fact that they look different from in front and from behind. To first approximation, the dark shadow pattern agrees with the bright Sunward-facing reflection pattern (what we usually see) but not necessarily with the backscatter pattern (which involves diffraction and other messy stuff). Here's a nice image showing all three (by pasting two images) side by side: http://farm9.staticflickr.com/8483/8285714929_54f4ccfc2d_b.jpg
2) The bluish white haze extending far to the right from 5 o'clock on the limb.
I think it's the E ring, but maybe it's the G ring. See: http://en.wikipedia.org/wiki/File:Saturn_outer_rings_labeled.jpg -- Robert Munafo -- mrob.com Follow me at: gplus.to/mrob - fb.com/mrob27 - twitter.com/mrob_27 - mrob27.wordpress.com - youtube.com/user/mrob143 - rilybot.blogspot.com
RWG's incomprehension is way ahead of mine --- I cannot make visual sense of this abstractly impressive graphic at all! WFL On 12/29/12, Bill Gosper <billgosper@gmail.com> wrote:
http://media.zenfs.com/en_us/News/Reuters/2012-12-19T035245Z_616564795_TM3E8... shows the ridiculously complicated illumination of Saturn's nightside by sunlight scattered off the rings, some of which is then viewed though the rings. At 4 o'clock on the limb, there is even an arc filtered through the dayside rings and then the upper atmosphere. But I don't understand: 1) Why the crisp silhouettes of the near rings against the (false color) green background seem discontinuous with the arcs outside the planet's shadow, presumably viewed by scattered, transmitted sunlight. 2) The bluish white haze extending far to the right from 5 o'clock on the limb. --rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (3)
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Bill Gosper -
Fred lunnon -
Robert Munafo