Re: Double shadow transit happening on Jupiter (12:30)

i was using an 8" SCT. Shadow sizes were easily distinguishable. But
as for color, they all looked black...You had a lot more photons to
work with ....

Thanks!

Doug

On Sep 4, 2009, at 2:01 PM, Steve Gottlieb wrote:

> It depends a lot on aperture, magnification and seeing conditions.
> In my 18-inch, the three dots were distinctive in size (the
> difference between Ganymede and Ganymede's shadow was discernable)
> and Ganymede had a relatively lighter color (still showed up well
> against the belt) than the two shadows. I was observing at 262x.
>
> Steve
>
>
> On Sep 4, 2009, at 11:42 AM, Randy Muller wrote:
>
>> On Fri, Sep 4, 2009 at 9:55 AM, Douglas Fairbairn<dgfairbairn@No-Spam
>> > wrote:
>>> Turns out I did see three black dots - all in the right places per
>>> Starry
>>> Nights.... two were shadows and one was Ganymede. So why was
>>> Ganymede dark?
>>
>> Ganymede has an albedo of .43. It is certainly darker than the light
>> tan colored belts on Jupiter, and I think it would look "black"
>> compared to them in a small telescope.
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