Why are there no visible stars in the background?
Who Took the Legendary Earthrise Photo from Apollo 8?
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Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#12Why are there no visible stars in the background?
Because it is daytime.
(If the camera exposure was set for the faint stars, then the sun-lit scene would be hugely overexposed.)
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#13Earlier quoted context omitted.
Thanks. I wasn't aware of that. I just remember the first time I ever saw that footage, couldn't believe what I was hearing, and haven't forgotten it. My own objection isn't even about government/state promotion of religion - though I'm not particularly a fan of that - it's that a scientific body like NASA comes out with "God created Earth". And I wouldn't even mind that if NASA stated it was their official position.…
You are conflating the official position of the organization with a statement made by one of its employees on company time. The linked decision thoroughly considers this point as well, and finds it unconvincing. NASA's official allegiance in matters of faith was found to be as nonexistent as befits a US government agency. The court recognizes that sometimes people say things of their own accord, for which they alone…
Amen!
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#14Why are there no visible stars in the background?
Because it is daytime. (If the camera exposure was set for the faint stars, then the sun-lit scene would be hugely overexposed.)
I am not sure this is the complete explanation.
On Earth we do not see stars because of light scattering (Rayleight and Mie) [0].
In the outer space there is no scattering and the light from each star represents a tiny point in the picture, but this point is bright. After all it comes from a sun. But the original image [1] has a dark background as well.
Maybe it is due to the fact that jpeg compression losses small artifacts or something else.
On some pictures it is possible to see tiny white points such as in [2]
[0] https://en.wikipedia.org/wiki/Diffuse_sky_radiation
[1] https://www.hq.nasa.gov/office/pao/History/alsj/a410/AS8-14-...
[2] https://www.hq.nasa.gov/office/pao/History/alsj/a410/AS8-15-...
(some non important edits, including changing link 2 which was a thumb view)
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#15Just to clarify, the earth does not rise on the moon (just wobbles). The earth appears to rise because the orbiter circling the moon.
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#16Earlier quoted context omitted.
Because it is daytime. (If the camera exposure was set for the faint stars, then the sun-lit scene would be hugely overexposed.)
I am not sure this is the complete explanation. On Earth we do not see stars because of light scattering (Rayleight and Mie) [0]. In the outer space there is no scattering and the light from each star represents a tiny point in the picture, but this point is bright. After all it comes from a sun. But the original image [1] has a dark background as well. Maybe it is due to the fact that jpeg compression losses small a…
We see stars during solar eclipses, so it is the scattering of the light of the sun that obscures them. It really _is_ the exposure issue, since the surface brightness of the Earth is that of full daylight and so full daytime exposures were needed. Stars will never show up unless longer exposures are used.
Here is an over exposed photo of Earth by Apollo 16 from the lunar surface, with stars visible:
https://en.wikipedia.org/wiki/File:Apollo_16_UV_photo_of_Ear...
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#17Earlier quoted context omitted.
Because it is daytime. (If the camera exposure was set for the faint stars, then the sun-lit scene would be hugely overexposed.)
I am not sure this is the complete explanation. On Earth we do not see stars because of light scattering (Rayleight and Mie) [0]. In the outer space there is no scattering and the light from each star represents a tiny point in the picture, but this point is bright. After all it comes from a sun. But the original image [1] has a dark background as well. Maybe it is due to the fact that jpeg compression losses small a…
[deleted]
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#18Why are there no visible stars in the background?
I once got curious about that myself, so I downloaded some of the full size black and white TIFFs from the NASA site. (I'd link them, but I'm not sure where the archive is today.)
Anyway, if you bring up the shadows a long way in Photoshop in some of the pictures you'll find some little dots that look a whole lot like stars.
If you'd like to test this for yourself, take some photos of the full moon with a telephoto lens. The moon is extremely bright, as nighttime objects go, and the amount of exposure needed by the camera to capture a photo is short. Edit: The moon will be properly exposed, the sky dark.
There's something called the Looney 11 rule, https://en.wikipedia.org/wiki/Looney_11_rule. Basically, you can set the camera to these settings and obtain a reliably exposed photo of the moon. There's a similar rule for objects on earth which are in full sunlight called the Sunny 16 rule. The important thing to note is that there is one camera stop difference between these settings. Objects in full sunlight on earth reflect twice as much light as the sunlight reflected from the moon. And in terms of photography, that is a trivial difference.
Try those Looney 11 camera settings indoors sometime. There's not even enough light in your house for those settings to work. You'll see the lightbulbs, some reflections, light coming in through windows, etc, but not much else.
The important point to take away is the difference in the amount of light between the stars in the sky and the surface of the moon, is significant. It's large enough that it doesn't fit into the exposure latitude of color transparency film used (see https://en.wikipedia.org/wiki/Exposure_latitude), and is very deep in the shadows of negative film if it registers at all.
But rather than take anyone's word, this is something anyone who has a camera can try for themselves.
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#19I'm glad they got the Earthrise Photo, because otherwise, six months before Apollo 11 gave the world a line which even impressed the Soviets, Apollo 8 would be remembered for this cringey, inane stuff[1]: https://www.youtube.com/watch?v=ToHhQUhdyBY [1] To avoid misunderstanding: this isn't an atheist/anti-religion post, it's about the aptness of such an utterance by personnel on a top scientific mission, from one of…
You're definitely coming off as an edge-lord for calling this inane. Today, I'm sure Twitter would melt because of it (you can't even have a shirt people don't like without causing outrage), but the country was very different back then. Plus these missions were more than a scientific endeavor, because it took more than science to put everything in place for it. It was the biggest accomplishment by us as a species, so they wanted mark it with what they considered the most important thing in their lives. To me it's cringey that you can't look at it objectively without taking some kind of offense to it. But hey, that's just me.
Re: Who Took the Legendary Earthrise Photo from Apollo 8?
#20Earlier quoted context omitted.
I am not sure this is the complete explanation. On Earth we do not see stars because of light scattering (Rayleight and Mie) [0]. In the outer space there is no scattering and the light from each star represents a tiny point in the picture, but this point is bright. After all it comes from a sun. But the original image [1] has a dark background as well. Maybe it is due to the fact that jpeg compression losses small a…
We see stars during solar eclipses, so it is the scattering of the light of the sun that obscures them. It really _is_ the exposure issue, since the surface brightness of the Earth is that of full daylight and so full daytime exposures were needed. Stars will never show up unless longer exposures are used. Here is an over exposed photo of Earth by Apollo 16 from the lunar surface, with stars visible: https://en.wikip…
I may not have been so clear (English is not my native tongue, etc), but you repeat what I wrote:
* it is the scattering of the light of the sun that obscures them
* On some pictures, stars are visible (I even provided a link)
However having said that you also say "It really _is_ the exposure issue" but it has nothing to do with light scattering?