Why can't you see stars while you are in space?

Question

This has been answered poorly many times before with answers about bright backgrounds, etc. But there are never any answers as to why pictures with very low light background, such as pictures of asteriods (NEAR) and others have no stars in the background. If you see pictures with stars in the background, the stars have been added.

One example of this deceit is at the site below where NASA has clearly superimposed the constellation Orion on top of the Aurora! You can clearly see that the stars are in front of the Aurora, not seen through the Aurora!! NASA continues to decieve the public over this star issue.

http://antwrp.gsfc.nasa.gov/apod/ap970126.html

Answer 1

Have you never seen any pictures from the Hubble telescope??
Stars all over the place mate! Wake Up.

Answer 2

There is no deception! Cameras don't have infinite dynamic range, and the stars are too underexposed to show up when a camera is set to daylight exposure. Asteroids are have low albedos, yes, but that doesn't mean that they are very dark up close. When a camera's exposure is set to record an object in daylight, such as the lunar surface, an asteroid at point-blank range, or the International Space Station, the stars simply don't receive enough exposure time to show up. There is no great conspiracy - it's basic photography.

If you're still not convinced, I suggest that you try an experiment. With a camera capable of manual exposure, use the "Sunny 16" rule for daylight photography. That is, set the aperture to f/16 and the shutter speed to the reciprocal of the ISO setting (e.g. 1/100 sec for ISO 100 film). Point the camera at the night sky and take a picture. You won't see any stars. Better yet, do this when the Moon is in the sky. The Moon will be well-exposed, but stars won't show up. That there's no atmosphere in space changes nothing.

That photo is perfectly normal. The aurora is inherently faint, and it requires a significant amount of exposure time to properly record. Since the exposure time is long, stars show up. And the stars weren't superimposed; the aurora reduces the contrast of the stars that it crosses in front of, meaning that the stars are much more difficult to spot.

I hope that this clarifies things for you.

Answer 3

Enternewid, why is it you can see lots and lots of stars out in the country, but only a few (or none) in the city?

The reason is because of the overhead lights. Try this experiment some time. Drive out into the country, on a clear dark night, and count the number of stars you see in the triangle formed by Vega, Dened, and Altaire. Then turn your car headlights on and gaze into the high beam for 60 seconds. Then look back at the star field.

You'll be doing good if you can even make out the three corner stars.

Your eye is much like a camera lens, just more sensitive. Take your digital camera outside some time and snap a photo of the night sky. How many stars appear in the photo? Far fewer than you can see. NASA's cameras work the same way.

In fact, increase the exposure time and snap a photo while holding the camera very still. Then do the same thing with some light source in the background. You can easily conduct this experiment yourself, and prove the explanation you have been given is indeed correct.

Answer 4

The Earth (and any other body) viewed from space is as bright as a sunny day on Earth (since it is reflecting the Sun's or the camera flashes rays). The stars are very dim. When the sun is going down, you don't see a majority of the stars until everything is dark. At twilight, you might see a few of the brightest - but with any serious light, they aren't bright enough to stand out.

Film has the same problem - if you let the film expose long enough to see the stars, the Earth would look like a big white ball - like the sun. Film is even more difficult than our eyes. If you have a photo taken outdoors in the sun, look at it. anything in the shade is almost black. If you went and took a picture in the shade, the sunlit portions would be seriously overexposed. To get a pretty picture of earth, they just don't do a long enough exposure to pick up stars.

Answer 5

The answer about bright backgrounds is the correct one. You can choose to believe it or not. Even an asteroid is bright compared to some distant star. Read up on real photography there is a lot more to it than the instruction book for your pocket digital camera lets on.

If you don't like that picture, complain to NASA, not to us. There is also the possibility that some of the points of light in the "foreground" were created by the camera lens though I have to agree that the picture looks like a photo shop jobbie with stars apparently between the Earth and the camera.

On the other hand, NASA and many other agencies with a scientific and engineering background assume some level of knowledge and understanding among those who check their sites and paper publications. Otherwise they would have to explain everything from first principles and they are not in the business of primary or secondary education.

BTW, if you are thinking that the Moon landings were faked, think again. If they had been, scientists and even radio amateurs from around the world would have spotted it immediately Particularly the Russians, but there were plenty of other people in other countries who would have known. The assertion that the Moon landings were faked is false.

Answer 6

Looks like this image was taken from low Earth orbit. The reason you can see stars (and the aurora) is because the exposure time of the film was long enough for the faint light to imprint photons upon the surface of the film substrait. If you were in orbit, you would be able to easily see the stars because your retina is MUCH more sensitive to photons than film. With your example of asteroids as the primary subject, the object is bright enough that the exposure time does not allow for the faint light of the stars to embed enough photons to generate an image.
So that you may better understand the what is happening here. Take a 100W light bulb and turn it on. Now look directly at the light bulb and try to read the lettering imprinted on the bulb. I dont think you will be able to read it unless you get real close to the bulb and stare at it for a long time. Eventually, the lettering will become clearly visible, but it does take a while, just keep staring at the illuminated bulb until you can see the lettering.
Good luck. I hope this helps you to see.

Answer 7

You can choose to believe the answers you have been given are poor, but that won't stop them being right. An object illuminated by the sun, whether that be the ISS, the moon, an asteroid or Neptune, will be bright enough to require exposure times that just won't capture stars on film or on the CCD. There is a picture of Neptune's rings that has stars in, because the exposure needed to image the tenuous, dark rings was long, but the part of the disc of Neptune that is visible in the picture is a bright, overexposed, undefined, flared blob.

that said they can be seen by the human eye under the right conditions. Seeing and photographing are very different things. No-one has ever said that satrs cannot be seen at all in space, only that they can only be seen under the right conditions, just as the stars can only be seen from Earth under the right conditions. Where I live now I can only ever see the very brightest stars, because there are too many light sources nearby and my eyes can't adapt enough to make out the fainter stars. From a pitch black observing site, however, I can see so many stars it's almost unbelievable.

Answer 8

So are you going to keep asking it until you get the answer you want to hear?

You can see stars in space, simple as that. Who persuaded you to believe otherwise? And how do you know they "superimposed" that constellation? You'd be surprised what photos can develope as. In that photo, it is somewhat apparent it is a time exposure, so the brighter stars bleed through as if they are on top. Obviously you are not into photography to make such blatent assumptions.

A bright source of light demands a faster shutter speed. In the surrounding low light conditions of the astro photography, if the shutter speed is set fast to capture one bright object, you lose exposure of the lesser light emitting objects in the distance, like stars. If you exposed the photo long enough to capture the dim objects, then your bright object would be much overexposed.

Answer 9

I suspect you question has been answered very well and that it was your understanding of that answer which was poor.

Clue: Despite your incorrect assumption, an asteroid is a very bright object, at least when you are as close to one as NEAR was. You cannot correctly expose a photograph of an asteroid and image the much fainter stars at the same time. Of course, this is the same logical answer that you were completely incapable of understanding before...so I doubt repeating it will help. Your ignorance of basic photography does not mean that NASA is engaged in a grand conspiracy.

As for your interpretation of the NASA aurora photograph...well, I see others have taken you to task on that monumental bit of miscomprehension.

Answer 10

You can see stars when you are in space (Yuri Gagarin said this), but you have to be in the Earths shadow because the brilliance of the sun and the reflected light from the Earths surface overpowers the relatively weak light from the stars.

Photos of objects like asteroids require exposure times from cameras that do not register starlight - the same principle that prevented stars from appearing in the Apollo mission photos.

If you go and stand under a streetlamp on a clear night you won't see any stars. Your eyes adjust to the streetlight and cannot register weaker starlight.

Cameras work in much the same way - long exposure times are needed to photograph stars and very often the result is like the one you included in your link.

Answer 11

When you see pics of asteroids, (Near.) the reason you do not see stars in the background is something called depth of field, a basic thing in photography, i.e ., focus.

If the near object is close and in sharp focus, the distant background is blurred, the degree of blurring can be varied by the aperture setting in conjunction with the light setting.

In view of the fact that the stars are nothing more then tiny dots of light, when they are blurred by the depth of field factor they disappear into the background, so it appears as if there are no stars.

In order to make the pictures look more like you would see it if you were able to with the naked eye, they add the stars.

What deceipt are you on about. Not another conspiracy theory, please!!! There are no such thing as stars, and its a government plot trying to convince us!! Is that it, LOL