Stars Can't Be Seen from Outer Space

Heres an image that seems to show some odd effects. What look like stars, when zoomed, have some strange colours and shapes. What's going on?
eol.jsc.nasa.gov...

originally posted by: GaryN
a reply to: onebigmonkey

No, it's you who don't understand. The telescope can collect the light OK, but the wavefront is not the same as the wavefront generated in the ionosphere/plasmasphere that Earth based telescopes see. You folk who think you know everything really annoy those of us who do.

So it's the wavefront that determines whether light is detectable or not detectable?

Before you accuse me of not having any idea about optical systems they use in space, read up on what a wavefront sensor is and what it's used for. There's the Wikipedia article, but the link you gave me has all the details in-depth. I'll give you a quote from one of the papers for convenience:

This software is a comprehensive suite of wavefront sensing and optical control tools designed to measure the wavefront and control the optical systems in order to correct for distortion.

originally posted by: GaryN
Heres an image that seems to show some odd effects. What look like stars, when zoomed, have some strange colours and shapes. What's going on?
eol.jsc.nasa.gov...

Because it's a long handheld shot, there is going to be camera shake.

a reply to: nataylor
I'll disagree, of course, but not because I don't think it looks like camera shake, but because I don't believe even NASAs hot-rod cameras could bring out stars with 1/8 at 6400.
www.cloudynights.com...
I can't determine what stars would have been visible at the time, as I am having trouble importing the latest ISS orbital figures into Celestia, due to the Excel file not importing properly into my open source equivalent of Excel. Means setting up a windows box and real Excel, which I'll do, but too busy just now. And Stelarium won't do what I need either, cute program though, and I'll set it up for my friend whos wife just bought him a telescope, as he doesn't know much about astronomy, and even less about computers. Maybe you could identify the stars?

@wildespace

So it's the wavefront that determines whether light is detectable or not detectable?

It's being able to focus, to put it simply, enough of the wavefront onto the ccd element to be able to trigger an electron. I have a friend who worked in Military R@D who told me that the lens material (classified) for the star trackers is insanely expensive, and they reject 90% of it when they make a batch. The lenses have to be shaped to such an amazing accuracy (the shape is classified) that it wasn't until the manufacturing technology reached a certain level that they could be produced. The software is classified of course, and at $400 to 800K a pop for the trackers, I don't think they are going to sell you the software, even if by some miracle you could create the optics. The latest star trackers are using the APS sensor, and they now can do everything in software, gets rid of the complex optics, but you don't think they'll be any cheaper do you? And you don't just need one sensor for going into space. The Sun sensors are only $15k a pop, what a deal!

originally posted by: GaryN
Heres an image that seems to show some odd effects. What look like stars, when zoomed, have some strange colours and shapes. What's going on?
eol.jsc.nasa.gov...

6400 lots of noise 1/8 of second shutter speed with focus even slightly out you will have problems with stars!

Don't have time to post an image will do later.

I was just watching an old video with Buzz Aldrin talking on Larry king show, and he mentioned seeing the stars from the viewing port of the Apollo capsule they were in.

I would say that would have more credibility than someone saying you can't see the stars.

If you can see the light from stars here on earth with all the light pollution in many places, you can see the stars if you are in interplanetary space, and even deep space is my belief. The Hubble can see galaxies within inter galactic space, but of course Hubble has a big mirror that gathers a lot more light than the human eye can, but I would bet that if you were in inter galactic space, you would see the light from many galaxies all around you.

originally posted by: GaryN
Heres an image that seems to show some odd effects. What look like stars, when zoomed, have some strange colours and shapes. What's going on?
eol.jsc.nasa.gov...

That image is out of focus, that's the main factor, along with digital noise and perhaps some atmospheric influence.

At f/1.4 (which is a very large aperture size compared to 5.6) I think it's quite possible to capture stars at ISO 6400 and 1/8s exposure.

It's being able to focus, to put it simply, enough of the wavefront onto the ccd element to be able to trigger an electron.

I wonder what exactly you mean by that. Focusing is focusing, it just creates a sharp image on the sensor/film/retina. Star trackers obviously need superior optics to create the best-focused image possible - for the sake of accuracy. I'll agree that, for the very faint stars (barely on the limit of detectability), good focusing is needed for them to register on the sensor. But for brighter stars, regular focusing that is done in photocameras and telescopes is sufficient. An unfocused blob of light is still light, even though it's spread over a larger area.

originally posted by: GaryN
a reply to: nataylor
I'll disagree, of course, but not because I don't think it looks like camera shake, but because I don't believe even NASAs hot-rod cameras could bring out stars with 1/8 at 6400.
www.cloudynights.com...
I can't determine what stars would have been visible at the time, as I am having trouble importing the latest ISS orbital figures into Celestia, due to the Excel file not importing properly into my open source equivalent of Excel. Means setting up a windows box and real Excel, which I'll do, but too busy just now. And Stelarium won't do what I need either, cute program though, and I'll set it up for my friend whos wife just bought him a telescope, as he doesn't know much about astronomy, and even less about computers. Maybe you could identify the stars?

That exposure at f/1.4, 1/8 sec, ISO 6400 is capturing 6400 times more light than one of the moon shots taken at f/5.6, 1/2000 sec, ISO 400.

At any rate, you can clearly see those are stars. Here's a screenshot from Starry Night Pro (click the link view a bigger version):

i.imgur.com...


And an animation switching back and forth between the photo and a screenshot:

i.imgur.com...

a reply to: GaryN

So lets see a link to a Canon 5D MK2 when the MK3 has been out since 2012 and the old my friend works with top secret tech that you cannot get info on REALLY!

Typical Star Tracker

Star Tracker CCD

You keep going on about the Sony a7s NOW as a Sony user myself I know about the camera and what it's capable of doing in low light now as it has a BOG STANDARD cmos sensor Full Frame size but only 12mp it has NO top secret tech either.

Now with the low pixel count on a full frame sensor the pixels are larger so get more hits by photons it's that simple.

PLEASE stop all the clutching at straws to try and convince people YOU would get more credit admitting YOU got it wrong instead of making things up that in the end just make YOU look kind of stupid.

a reply to: nataylor

And an animation switching back and forth between the photo and a screenshot:

Excellent work Sir! So they are stars, that's question one out of the way. With the exposure and visibility of those stars, I'll maybe try and get a consensus from a few experts, but my own belief is that they would not show up with a similar exposure, from Earth, with a stock Nikon. Maybe NASA lists the serial numbers of their tweaked cameras, getting IR sensitivity out of the way would be another step required too.
And as for asking some experts, I'll start with members here before I ask some professional image forensics experts about the footage from the Maurer 16mm motion picture camera on Gemini 12. Here is a single frame
i1.ytimg.com...
( I put this image in my library, but when I go to add the image from here, I have a little box at the top of the screen with just an X at the right to close the window. Why is adding images such a pain on ATS?)
and the video is here. Watch from 11:52 for the segment I am interested in.
www.youtube.com...
Looks like a plasma cloud energised by solar radiation, blue light from hydrogen Balmer emissions, tendrils at the edge where it is looking for electrons. Of course, most will see what they want to see to fit their own mental models, including myself, but this seems so obvious.
Another view would be lens effects with the Sun at a certain angle, blue from some internal lens prisming effect?
Looks like I may as well set up a dedicated Windows box for this kind of stuff too.

a reply to: GaryN

Here's a random photo I found on Flickr: Link

It was taken at f/1.8, 1/13 sec, ISO 6400, -2 EV. So that's 3.33 stops *less* light than the photo from the ISS. And you can see some bright stars.

And that Gemini film is definitely sun glare.

Edit: And here's the serial number of the D4 that was used to take the photographs on the ISS: 2071123. Not sure what that will tell you, though. That camera definitely hasn't been modified by having the IR filter removed. The earth photography would look much different if it had been removed.

a reply to: nataylor
Those stars when magnified do not look much like the ISS photos, but after Looking at the D4 specs, I'd have to agree it could be possible, my last retort then would be that it is the ionosphere that is creating the light being imaged, so lets try the D4 shot at the same settings from the Zenith port.
It will be interesting to hear what the image forensics people say about the Gemini footage, and before I started looking into all this, I would have said it was some lens effect, but with the Russians talking about seeing blue stars, from likely a similar altitude, and the blue moon images from the cupola, I'm not so sure. It looks to me that the Gemini shot is of what is called an ionospheric perturbation, and they are at about the correct altitude, and they can be detected by radio waves, so NASA would know where they would be at any given time to use them for the experiment.
www.astrosurf.com...

a reply to: GaryN

So you think this:



Is capable of imaging, on 16mm moving film, 'ionospheric perturbations'?

Do tell.

PS It's a lens flare.

In addition to just being cool as hell, the raw images from New Horizons' LORRI camera show lots of stars.

Welcome to the New Horizons image site, where NASA and the New Horizons mission are happy to provide these JPEG images - displayed in raw form without special processing - for the public to use and enjoy. These JPEGs of images taken by the LOng Range Reconnaissance Imager (LORRI) are generally posted within 48 hours after receipt at the New Horizons Science Operations Center. The date/time listed in the image caption is when the picture was taken by the spacecraft, though receipt of the data on Earth could be many days later, depending on when the image is downloaded from New Horizons.

pluto.jhuapl.edu...

originally posted by: GaryN
a reply to: nataylor
Those stars when magnified do not look much like the ISS photos, but after Looking at the D4 specs, I'd have to agree it could be possible, my last retort then would be that it is the ionosphere that is creating the light being imaged, so lets try the D4 shot at the same settings from the Zenith port.
It will be interesting to hear what the image forensics people say about the Gemini footage, and before I started looking into all this, I would have said it was some lens effect, but with the Russians talking about seeing blue stars, from likely a similar altitude, and the blue moon images from the cupola, I'm not so sure. It looks to me that the Gemini shot is of what is called an ionospheric perturbation, and they are at about the correct altitude, and they can be detected by radio waves, so NASA would know where they would be at any given time to use them for the experiment.
www.astrosurf.com...

The film has been OVER SATURATED by the Sun and the lens shows some lens flare, it's like a burnt out highlight in a modern digital image pointed towards a bright source of light .

As for the comment that the stars DON'T look the same as the Nikon picture you were told it is out of focus, the stars can look like nice points of light on an image shown at a small size but see it enlarge and they often look like rings or blobs depending on lens/focus

a reply to: jokerzwild

The LORRI camera is a Star Tracker, it should be able to see stars, your eyes out there wouldn't.

wmd, I have had a professional photographer, old school guy who did all his own developing too, look at the single frame, and he thinks there is lens bloom, and showed be some images. There is for sure a good similarity, but when I showed him the movie he said that it certainly looked like there is a physical cloud there, and bloom from a bright source just out of view. I then showed him the plasma perturbation, and explained as simply as I could what it was and where they are found, and he said he believed I was right. This had nothing to do with the visibility of stars, I never even mentioned that part, but I think NASA did actually catch one of the perturbations in action, and they would know just where and when to be in order to see it as they could locate it by radio waves.
We have one or maybe 2 film and video academies not too far from me, going to drop in on them and see if they'd have a look, and an image processing/CGI section, could be interesting. Of course my real motive is to try and eye some cute chicks, but they don't have to know that! Haven't gone to any online experts yet, but will if I get more positive reaction locally.

a reply to: GaryN

Well if you eye some cute chicks get some pictures for us old guys, I have been taking pictures for 35+ years starting with a FULLY MANUAL FILM SLR developing in a friends darkroom , running a small camera club with him in the mid 80's and starting to edit images on Ataris. Then moving on to digital 2,5,8 and now 16mp cameras.

My cameras have been hooked up to microscopes , telescopes taken portraits, landscapes, wildlife & sports shots, long exposure, high speed flash there is not much I haven't tried.

To give you an idea, I am going to a motorbike race event this weekend on one day I will probably take between 500-700 pictures all in raw format. Single shots to 5-7 frames per second.

When you take literally 10,000+ images a year you get a very good understanding on what you see in images and how they are taken.

Get your Nikon out you could recreate your claimed plasma cloud here on the surface it's over exposure & flare nothing else.

a reply to: wmd_2008

Typical Star Tracker Star Tracker CCD

That's old school stuff in the star tracker world, moves very quickly. The 3 transistor APS sensor is the thing now, very small, very versatile.
artes.esa.int...
It is what the Nav Cam images from Rosetta are imaging comet 67P with.
But from Earth, or from 40,000 ft anyway, it seems film beats them all:
The Milky Way
www.musc.edu...
Haleys comet with ion tail
www.musc.edu...
Don't know the exposure details, but I'm told they are available, just fill out the needed paperwork.
mainweb-v.musc.edu...
And by some estimates, a 35mm ASA 100 film with have the equivalent of a 50 mega pixel image sensor, not easy for direct comparison, but the grains are smaller than present pixels, so far better anyway I'd think. Hard to retrieve film from space though, and if you on-bard process, than you have to scan it, so limited by the scanner resolution.
Anyway, seems like ATS does not have many visitors interested in this kind of discussion, a little surprising but not unexpected when they'd rather see the computer art images produced by NASA from Hubble, which bear no relation to what is actually visible out there, which is really just blackness.
Edit: Just found the camera setup image for the above images, may be interesting to another old-schooler.
www3.telus.net...

a reply to: GaryN

That sure looks like a fleet!!

originally posted by: ignorant_ape
a reply to: cooperton

the simplest argument against this idiocy - the sun is a star

One of the most concise, precise, and beautiful explanations I have ever seen on any topic. Well done!