Re: Why is ISS still visible in Earth's shadow?

From: fvalcho@yahoo.com
Date: Mon May 02 2011 - 02:58:24 UTC

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    I've watched the ISS fade into the shadow in N.Cal/SanFran area. At this Lat the Suns rays are north of the equator (northern summer) and the ISS will still disappear rather quickly, turning brownish as it leaves the sun behind. If you blink, you'll miss the twlight fade. Any sat. That enters termination has an extremely short viewing period. 
    If moonlight has any effect, the moon has to be extremely low on the horizon, otherwise it only reflects off surfaces not visible from a ground perspective. 
    I can't believe any earths city lighting would have ANY effect at all.
    Sent from my Verizon Wireless BlackBerry
    
    -----Original Message-----
    From: Bob King <nightsky55@gmail.com>
    Sender: seesat-l-bounces+fvalcho=yahoo.com@satobs.org
    Date: Sun, 1 May 2011 21:43:02 
    To: <seesat-l@satobs.org>
    Subject: Re: Why is ISS still visible in Earth's shadow?
    
    Hi George and all,
    So it would appear to be residual, after-sunset light -- in other
    words, can we say twilight? I've followed in binoculars until it's
    around 8th magnitude and it appears pale white after the sunset colors
    are gone. It may be brownish as you suggest, but at such a dim
    magnitude, no color is visible.
    Bob
    
    On Sun, May 1, 2011 at 8:53 PM, George Roberts <gr@gr5.org> wrote:
    > From the ISS's perspective it sees the sun set.  When the Sun is just on the
    > edge of the horizon it sees a redish light so the ISS starts to turn red.
    > After the sun sets the ISS still sees a large arc of the earth's atmosphere
    > as a bright red sunset arc.  At this point the ISS is getting quite dark
    > brown.  At some point after this the ISS sees no 'sunset' light at all, it
    > should be too dark to see even I would expect in a full moon but not sure
    > about that.
    >
    > The earthshine concept isn't right - there is no earthshine once the sun
    > sets behind the earth's limb.  Maybe moonshine but no earthshine.  The moon
    > sees earthshine when it is a thin crescent and the earth see's moonshine
    > especially when full.
    >
    > - George Roberts
    > http://gr5.org
    > -----Original Message----- From: Bob King
    > Sent: Sunday, May 01, 2011 8:36 PM
    > To: seesat-l@satobs.org
    > Subject: Why is ISS still visible in Earth's shadow?
    >
    > Hi everyone,
    > I've always wanted to ask this question. No doubt some of you have
    > followed the space station into Earth's shadow, where it's visible for
    > some time with binoculars. Is it being illuminated by the moon or ???
    > Thank you for your help!
    > Best wishes,
    > Bob
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