[AZ-Observing] Re: Images of Occultation of Venus

Hi Wayne,
NO "Green Flash" could possibly be seen on Venus during the lunar 
occultation, for the following reasons:
(1) As you correctly stated, there is no atmosphere on the Moon.
(2) BOTH the Moon and Venus were being illuminated by the Sun, off at an 
angle.  We are seeing both via the REFLECTED light.
So there is no light being transmitted past the limb of the Moon and 
THROUGH the edge of the Venusian atmosphere, and therefore, no 
refracting medium to separate the various colors, as in the case when we 
see the Green Flash on the Earth, as Sunlight is refracted upward and 
separated into various colors... Green being the highest of the 
refracted rays, and therefore, the last to be seen as the disk of the 
Sun has already gone over the horizon.  (We are actually seeing 
multiple, overlapping images in separate colors of the Sun's disk from 
below the horizon.)
Gene Lucas (17250)
Wayne (aka Mr. Galaxy) wrote:
> 15480 Empire Rd.
> Benson, AZ 85602
> hm ph: 520-586-2244
> I just had a chance to view your exquisite video of the Venus occultation, 
> Tom (and, I assume, Jennifer!). Interesting is the spillover (irradiance, 
> according to Gene) of Venus' image onto the moon's surface in your imagery. I 
> understand some people saw the effect visually though I did not, mostly, I 
> suspect because I had a large enough image scale with my 13-inch f/5.5 
> telescope and 16mm eyepiece. 
> One effect that occurred to me to try and see was a Venusian green flash as 
> the last remnants of its disk disappeared behind the moon. Comments as to why 
> or why not the phenomenon should or should not have been expected would be 
> appreciated. The moon doesn't have an atmosphere, of course, while the earth 
> does and is the reason why we see the green flash happen with the sun from 
> our vantage point on earth. Venus does have a very thick atmosphere and even 
> though it is disappearing behind the sharp edge of the atmosphereless moon I 
> would have thought that some effect should have been seen. 
> I was fascinated by how easy Venus was able to be seen after the sun had 
> risen, especially with the moon being used as a reference, and also the 
> clouds, when they were our of the way! 
> Clear skies, 
> Wayne (aka Mr. Galaxy)
[ref . to Tom Polakis' interesting video of the Venus occultation 
snipped -- GL]
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