Comments and questions about the
APOD on the main view screen.
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Ann
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by Ann » Fri Nov 06, 2020 5:10 am
Yeah, well... Moon over ISS, ISS over the Moon - what's the difference?
It's all just free fall in curved space anyway.
Ann
Color Commentator
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BDanielMayfield
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by BDanielMayfield » Fri Nov 06, 2020 5:39 am
Interesting geometry here. We’re seeing an unlit side of ISS in front of a sunlit part of the Moon. ISS must have been inside the Earth’s shadow at the time.
Just as zero is not equal to infinity, everything coming from nothing is illogical.
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Chris Peterson
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by Chris Peterson » Fri Nov 06, 2020 2:15 pm
BDanielMayfield wrote: ↑Fri Nov 06, 2020 5:39 am
Interesting geometry here. We’re seeing an unlit side of ISS in front of a sunlit part of the Moon. ISS must have been inside the Earth’s shadow at the time.
The Moon just three days past full, and imaged near midnight. No way that the ISS could be anywhere else than in shadow.
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orin stepanek
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by orin stepanek » Fri Nov 06, 2020 2:23 pm
Neat photo of ISS passing over Luna! Think I'll use it as a wallpaper!
![Wink :wink:](./images/smilies/icon_wink.gif)
Orin
Smile today; tomorrow's another day!
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WSODONNELL2
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by WSODONNELL2 » Fri Nov 06, 2020 2:54 pm
"Oh Lord, your sea is so great, and my boat is so small"
Fisherman's prayer, origin obscure.
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MarkBour
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by MarkBour » Fri Nov 06, 2020 7:27 pm
Chris Peterson wrote: ↑Fri Nov 06, 2020 2:15 pm
BDanielMayfield wrote: ↑Fri Nov 06, 2020 5:39 am
Interesting geometry here. We’re seeing an unlit side of ISS in front of a sunlit part of the Moon. ISS must have been inside the Earth’s shadow at the time.
The Moon just three days past full, and imaged near midnight. No way that the ISS could be anywhere else than in shadow.
So, would that mean that the photographer had no way to track the ISS visually as it approached conjunction with the Moon? Would Derek Demeter have just aimed the shot and used sufficiently precise data from some source to know when this event would happen? Would he have had to have known this down to a matter of seconds? Maybe a series of shots were taken in rapid fire around the moment of the transit? The high resolution image is wonderfully detailed in its rendering of the space station shape, I guess as you are both saying, there's no light bouncing off of it, it's all a silhouette!
Mark Goldfain
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Chris Peterson
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by Chris Peterson » Fri Nov 06, 2020 9:49 pm
MarkBour wrote: ↑Fri Nov 06, 2020 7:27 pm
Chris Peterson wrote: ↑Fri Nov 06, 2020 2:15 pm
BDanielMayfield wrote: ↑Fri Nov 06, 2020 5:39 am
Interesting geometry here. We’re seeing an unlit side of ISS in front of a sunlit part of the Moon. ISS must have been inside the Earth’s shadow at the time.
The Moon just three days past full, and imaged near midnight. No way that the ISS could be anywhere else than in shadow.
So, would that mean that the photographer had no way to track the ISS visually as it approached conjunction with the Moon? Would Derek Demeter have just aimed the shot and used sufficiently precise data from some source to know when this event would happen? Would he have had to have known this down to a matter of seconds? Maybe a series of shots were taken in rapid fire around the moment of the transit? The high resolution image is wonderfully detailed in its rendering of the space station shape, I guess as you are both saying, there's no light bouncing off of it, it's all a silhouette!
Right, I don't think it would be visible. But the orbit is very well characterized, so capturing it blind shouldn't be a big deal with an accurate time source (like GPS). I posted a
capture I made earlier this year. This was around sunset, and moonrise, so the ISS was much farther away than in today's image. But you can clearly see what it looks like in front of the Moon when it is in sunlight. Brighter than the Moon surface, in fact.
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MarkBour
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by MarkBour » Fri Nov 06, 2020 11:02 pm
Chris Peterson wrote: ↑Fri Nov 06, 2020 9:49 pm
I posted a
capture I made earlier this year. This was around sunset, and moonrise, so the ISS was much farther away than in today's image. But you can clearly see what it looks like in front of the Moon when it is in sunlight. Brighter than the Moon surface, in fact.
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20200604_stack.jpg
Thanks, I always appreciate these explanations and examples.
This one is
very nice. And I really like the video you made of some of the frames, posted at that link on cloudbait.com.
Mark Goldfain