Stars/no stars - and other space oddities

If NASA faked the moon landings, does the agency have any credibility at all? Was the Space Shuttle program also a hoax? Is the International Space Station another one? Do not dismiss these hypotheses offhand. Check out our wider NASA research and make up your own mind about it all.
hoi.polloi
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Re: Stars/no stars - and other space oddities

Unread post by hoi.polloi »

molodyets wrote:The blue sky disappears at about 9km
Huh? No. :huh:

The sky is virtually the same on long haul flights. Stars. Moon. Sun. Blue sky.

You can observe weather below, feel high altitude air currents and so on.

I am not sure what the discussion is here until we at least establish we know this much. For those that haven't been on many long haul flights, I understand your skepticism (or sarcasm). Take it from someone who has been traveling back and forth across the Atlantic for a quarter century, often gazing out the window admiring nature and the cosmos.

There may be some color or spectrum differences, and perhaps some stars might disappear. That may be true enough. But it would require some closer observation by people attentive to such differences. Maybe we've all been missing something obvious.
aa5
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Re: Stars/no stars - and other space oddities

Unread post by aa5 »

If Hoi has observed stars and the Moon out the window on his many long haul flights then I feel confident in saying that stars and the Moon are observable at least up to the altitude of those flights.

Doing a quick research on how high long haul flights fly at, it appears they cruise at between 9km and 11km altitude.

I think those high altitude balloons go up to ~30km, before the air is too thin to allow further ascent.
pov603
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Re: Stars/no stars - and other space oddities

Unread post by pov603 »

:) between 9 & 11 km!
molodyets
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Re: Stars/no stars - and other space oddities

Unread post by molodyets »

aa5 » July 31st, 2017, 5:02 am wrote:If Hoi has observed stars and the Moon out the window on his many long haul flights then I feel confident in saying that stars and the Moon are observable at least up to the altitude of those flights.

Doing a quick research on how high long haul flights fly at, it appears they cruise at between 9km and 11km altitude.

I think those high altitude balloons go up to ~30km, before the air is too thin to allow further ascent.
I'm glad Hoi corrected that piece of information. It forced me to review where I found it which at the time seemed quite low, ~9 km. The balloon video with this information was of lower quality, but was one of the few that gave enough altitude readings on the way up. I found better videos this morning, below. They indicate that the altitude is about 21 km (70,000 ft) when the sky begins to turn black. As a side note, most videos available on the web are from GoPro cameras which might have too many digital corrections to make any definite conclusions. The other video didn't indicate what camera they used.

The following video shows a camera view of the sky and an altimeter reading during the entire trip. The sky begins to turn black around 70,000 ft, as indicated by the camera pointing upward: youtube.com/watch?v=hceMXAQWWN8. Another video agrees with the first and shows the view from a U2 spy plane at 70,000 ft., youtube.com/watch?v=q48Swb2ATww. Although the pilot doesn't point the camera up, the horizon is dark blue, and darkens as the angle upward increases.
hoi.polloi
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Re: Stars/no stars - and other space oddities

Unread post by hoi.polloi »


full link: http://www.youtube.com/watch?v=hceMXAQWWN8
High Altitude Balloon 7 (Gopro Hero 3 & 4 Cameras) published by Dwayne Kellum on Feb 26, 2017

At 2 hrs 20 min and 16 seconds, and again at 2:20:47, you can see a bright light pan by. Does this seem like a bright star, planet or city light? Or is it some lens flare?

Regarding stars, it could be that the f-stop and such don't change automatically with the making of the video referenced, in which case stars would not be getting their deserved exposure? I don't know, but it seems to me stars should be visible and yet they are not. Hmm.

Off-topic comments:

It seems odd and yet not odd that the hip hop track playing mentions "Illuminati". Don't many artists happily mention it without knowing what it is? The whole song is about trying to find the truth.

Not to get dragged into that particular discussion haunting independent researchers lately, but it might also be noted that if this video is legit, it quite clearly shows curvature around this time in the video, but apparently (that is argued by YouTube commenters) from lens distortion. B)
Intothevoid
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Re: Stars/no stars - and other space oddities

Unread post by Intothevoid »

aa5 » July 29th, 2017, 9:42 pm wrote:Maybe one day a person with a window seat on a long haul flight will look out the window and double check for stars and also check for the Moon. It seems they all go to sleep though.
I asked our process engineer from work to look for stars when he took a commercial flight over the Atlantic at night last year. He was perplexed as the answer was no stars. I read somewhere that they may be more visible at certain times of the year than others. I have no doubt that Hoi has seen them and hope I get another chance to look for them again myself.
bongostaple
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Re: Stars/no stars - and other space oddities

Unread post by bongostaple »

I'd forgotten about this thread - I decided to check this out for myself a year or so ago, as I was doing a lot of long-haul at the time for business. Aeroplane windows, being fairly thick units, and lots of internal reflections, made it difficult, but when the interior lights were mostly off I had a good look. I could see stars for sure, but not all that many. I would put that down to the glazing making it difficult. But nevertheless, at about 36,000 feet / just under 7 miles / about 11 km, stars were visible. The sky was pretty dark, but it was night time, so I don't know about the sky going black during the day - I think I'd have noticed that if it happened, on plenty of other flights.

Higher up, we only have military aircraft, which none of us here can hop on and try out, or high altitude hot-air balloon flights, the 'amateur' ones being what we get to see. I really don't see a GoPro camera having sufficient dynamic range to pick up stars, they automatically adjust exposure throughout recording, so the only interesting situation would be if one was pointed away from the earth so that the exposure would open up a bit. And funnily enough, I haven't seen any video clips where anyone has done this. I'd like to see some though...
molodyets
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Re: Stars/no stars - and other space oddities

Unread post by molodyets »

hoi.polloi » July 31st, 2017, 4:46 pm wrote:
full link: http://www.youtube.com/watch?v=hceMXAQWWN8
High Altitude Balloon 7 (Gopro Hero 3 & 4 Cameras) published by Dwayne Kellum on Feb 26, 2017

At 2 hrs 20 min and 16 seconds, and again at 2:20:47, you can see a bright light pan by. Does this seem like a bright star, planet or city light? Or is it some lens flare?

Regarding stars, it could be that the f-stop and such don't change automatically with the making of the video referenced, in which case stars would not be getting their deserved exposure? I don't know, but it seems to me stars should be visible and yet they are not. Hmm.
The bright light at 2:20:47 is a great find. Although, I think it might be a piece of the balloon reflecting the sunlight, the object looked smaller.

I am very tempted to do one of these flights. I want to see the moon which is mysteriously absent from the videos that I could find. I also would love to view the sun through a filter so the light doesn't saturate the sensors.

Regardless of the camera exposure settings, the upward facing camera does capture the blue sky, even when it is very faint. From this we can conclude that it is sensitive to the low light levels and should show the stars. Unfortunately, the bright balloon in that view forces the camera to adjust to the higher light level. If the camera pointed to the sky, without a bright object in it, that would be more conclusive evidence if it still didn't show stars. Since the camera can show the faint blue light of the background, the stars should at least show as blurry spots. It's similar to how we begin to see the brightest stars while the sky is still blue.
NotRappaport
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Re: Stars/no stars - and other space oddities

Unread post by NotRappaport »

hoi.polloi » July 31st, 2017, 7:46 am wrote:
full link: http://www.youtube.com/watch?v=hceMXAQWWN8
High Altitude Balloon 7 (Gopro Hero 3 & 4 Cameras) published by Dwayne Kellum on Feb 26, 2017

At 2 hrs 20 min and 16 seconds, and again at 2:20:47, you can see a bright light pan by. Does this seem like a bright star, planet or city light? Or is it some lens flare?
Assuming the lights you refer to are the ones shown in this gif (taken from the YouTube video):

Image

A larger image, showing two lights (both streaked due to camera motion):

Image

These are approximately due West, in the direction of the setting sun. Using Stellarium, we can set the date to January 30, 2017, and time to about 8pm PST (UTC-8:00), and location to N36°43'05"/W120°57'47" to match the time/location coordinates of the video. At that time, in the West we see:

Image

From this we can conclude the main bright light in the video is certainly the moon and the dimmer light (only seen in some sequences) is Venus. The Moon appears quite small because it's angular diameter is less than 1/2° and the GoPro Hero4's field of view (FOV) is quite wide - between 73.6° and 149.2° on the diagonal (depending on if set to "Narrow", "Medium", or "Wide" FOV).

Venus of course is much brighter than any other planet or star in the sky, so it stands to reason that it would be visible (although clealy dim relative to the Moon) while other stars would not be seen.

Now as for the astroNots ludicrous claim that space is black with no stars when viewed from space... well, if that were true their beloved "Hubble" telescope would only show black images.

Stars won't appear in many photographs due to exposure (f-stop/ISO) settings not being set for very low light conditions. I do some sky photography occasionally (strictly amateur) and have noticed the settings necessary to pick up stars in the sky are about the same as the settings necessary to see the aldebo of the unlit portion of the moon (which of course massively overexposes the lit portion of the moon.
Exposure: 1/10 second, ISO 100 f/9.1
Image

Exposure: 1/5 second, ISO 3200 f/5.7
Image
In the first photo, no stars can be seen. In the second, a couple of stars are visible
molodyets
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Re: Stars/no stars - and other space oddities

Unread post by molodyets »

NotRappaport » October 4th, 2017, 9:43 pm wrote:
These are approximately due West, in the direction of the setting sun. Using Stellarium, we can set the date to January 30, 2017, and time to about 8pm PST (UTC-8:00), and location to N36°43'05"/W120°57'47" to match the time/location coordinates of the video.

From this we can conclude the main bright light in the video is certainly the moon and the dimmer light (only seen in some sequences) is Venus. The Moon appears quite small because it's angular diameter is less than 1/2° and the GoPro Hero4's field of view (FOV) is quite wide - between 73.6° and 149.2° on the diagonal (depending on if set to "Narrow", "Medium", or "Wide" FOV).

Venus of course is much brighter than any other planet or star in the sky, so it stands to reason that it would be visible (although clealy dim relative to the Moon) while other stars would not be seen.
Thanks for the analysis. This is the first time I've seen the Moon or Venus on these videos.
NotRappaport
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Re: Stars/no stars - and other space oddities

Unread post by NotRappaport »

Here's an even better illustration that the lights are indeed the Moon and Venus. I set the landscape to "ocean" and projection to "perspective" so the horizon is straight and unobstructed. Rotating the video frame so the horizon overlaps the Stellarium screenshot shows the match is perfect:

Image
molodyets
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Re: Stars/no stars - and other space oddities

Unread post by molodyets »

NotRappaport » October 4th, 2017, 9:43 pm wrote: Now as for the astroNots ludicrous claim that space is black with no stars when viewed from space... well, if that were true their beloved "Hubble" telescope would only show black images.
That's assuming their hubble telescope is actually taking the pictures, a lie within a lie:).

I may be mistaken, but when I've watched astronots make that claim, don't they say or hint that the stars are too faint to see, due to the brightness of the Earth, or sunlight, or the dark tint of their protective shielding?

I've read the claim from a few sources (possibly referencing a single source) that the Hubble images are really taken from the flying infrared observatory, SOFIA. If you visit their site: https://www.nasa.gov/mission_pages/SOFI ... index.html they'll give several reasons for using infrared sensors rather than using the visible spectrum. They may be telling the truth, or attempting to mislead the public. I can't say for sure, but one reason for them to lie, would be to cover up the fact that at a high altitude, the stars cannot be detected in the visible spectrum.

In your previous post, you showed pretty conclusively that the lights on the high altitude video were actually Venus and the Moon, but those are not stars. You also showed how exposure settings will affect the ability to record star light which everyone already knows. I'm just not convinced that the situation is the same at high altitude where the stars should be much brighter. I'm not glued to either conclusion, but my gut instinct says their cameras would be able to see the stars in these videos. If the stars are not showing in the visible spectrum, the implications would be too great to dismiss without more evidence, which is my reason for wanting more evidence before I move on.

Here's an example from their site, showing the difference between IR and visible pictures. Why did they show the IR image as so much blurrier and the visible one so much clearer? Food for thought. I have some possible answers, but I don't think that's as important as my other points.
Image
NotRappaport
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Re: Stars/no stars - and other space oddities

Unread post by NotRappaport »

molodyets » December 8th, 2017, 5:26 pm wrote:I'm just not convinced that the situation is the same at high altitude where the stars should be much brighter
...
my gut instinct says their cameras would be able to see the stars in these videos.
Regardless of how much brighter we think stars would be when viewed from that altitude, the Moon and Venus would also be that much brighter. By looking at how bright Venus is in the video, we can easily determine how bright a star would look in comparison.
Image

It helps to be familiar with the brightness magnitude scale. In the video the Moon is at crescent phase (10% illuminated) and it's brightness is magnitude -8.42. Venus at that time was at 40% phase and its magnitude was -4.56. Due to the way the magnitude scale works, this is a dfference in brightness of about 9.7x, and we can see the difference in the above picture.

In comparison , the brightest star, Sirius, at magnitude -1.45 would be about 7.8x dimmer than Venus and is unlikely to be seen at all. The next brightest star (visibile from the Northern Hemisphere at the time the video was made) is Vega at magnitude 0: 11.5x dimmer than Venus. All the rest of the stars in the sky are dimmer still.
molodyets » December 8th, 2017, 5:26 pm wrote:Here's an example from their site, showing the difference between IR and visible pictures. Why did they show the IR image as so much blurrier and the visible one so much clearer?
I think there might be a few different factors at play, but the dominant one is probably the fact that the resolving power of a telescope with a given aperture size decreases with longer wavelengths. The mostly far-infrared wavelengths in the image (5.4, 24, and 37 μm) are much longer than visible light wavelengths, which range between 0.38μm (violet) and 0.75μm (red).
Altair
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Re: Stars/no stars - and other space oddities

Unread post by Altair »

Anyway, it's quite strange that down on Earth seems to be no problem in photographing scenes where stars are quite apparent, like this 360º shoot in Google Maps. I can understand that a photo in daylight requires a small aperture and hence small and dim objects would not appear. But how about 'night' pictures in space where there are no stars also?
NotRappaport
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Re: Stars/no stars - and other space oddities

Unread post by NotRappaport »

Altair » December 9th, 2017, 4:04 am wrote:it's quite strange that down on Earth seems to be no problem in photographing scenes where stars are quite apparent, like this 360º shoot in Google Maps.
Look how bright the Moon is in that image - it's obviously a long exposure. My guess would be 5-10 seconds based on experience and the minimal amount of streaking in the stars.

Photographing stars is no problem if you use the right settings to photograph them, but anything else in the scene that is not also very dim will be massively overexposed (the Moon, for example). If the exposure were instead set to show a clear image of the Moon, the stars would not be seen (nor would much of the ground scenery, which is lit by Moonlight).
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