Stars Can't Be Seen from Outer Space

originally posted by: GaryN

I mean photons do not travel long distances in the vacuum.

what?

do you live in either colorado or washington state?

because the only explanation for that statement is you're smoking way too much dope

so how does the photon's emitted by the sun get here? how did a supernova, i can't remember which one, made the night sky light up like dawn and cast shadows?

how do you explain that i can shoot a laser to the moon and detect the reflection back?

how can the picture from voyager record this i.stack.imgur.com...

because by your explanation nothing should be visible in this picture

I mean photons do not travel long distances in the vacuum.

After that, who can put much stock in the other things you say.

originally posted by: GaryN
From Earth, a Canon A60, 2 MP shot. You don't think Chang'e or Curiosity has at least as good a camera?

Megapixels have nothing to do with light sensitivity. In fact, a smaller sensor with larger pixels would be better at capturing faint light.

That the Chinese said" Oh, were going to the Moon, but lets not think about some astrophotography, waste of time and money?" I doubt it.

Chang'e lander has a telescope-mounted camera for UV astrophotography. They have chosen UV for scientific reasons, not because the camera wouldn't be able to capture stars in visible light.

Forget Hubble, it sees what our eyes never will, and we are talking about human visibility of stars or planets, don't you get that?

The Hubble captures light in the visible spectrum (along with near-infrared), using a digital sensor just like any other digital camera. You can find documentation about the various filters used by the Hubble, and see that several of them fall into the red, green, or blue part of the spectrum.

we are talking about what space would look like to human vision, and away from a planet with no or little atmosphere, it will be pitch black.

So how did Apollo astronauts use stars for navigation in cislunar space if they couldn't locate them using their eyes first?

how can the picture from voyager record this

That's a screen shot from Celestia by the looks of it, not a picture. What you smokin?

Megapixels have nothing to do with light sensitivity. In fact, a smaller sensor with larger pixels would be better at capturing faint light.

Correct.The curiosity mast cameras use a 3 MP sensor, as does my Nikon Coolpix 990, and I can take good star, moon, and conjunction images quite well. The Curiosity cameras are also 3 MP, and there is no reason they should not be able to get as good images as I can. Here's an image from the same camera as mine, with dark frame subtraction, but even without that, the Moon and planets are easily visible.
reductionism.net.seanic.net...
So maybe the ISS crew needs to downgrade from those much newer Nikons to get some conjunction images?

do you live in either colorado or washington state?


because the only explanation for that statement is you're smoking way too much dope

B.C. actually, Bud. Yeah, maybe you are correct, I'm delusional. I'll check myself into the local loony-bin and get back to you all when I'm clean, maybe I'll realise the error of my ways.

so how does the photon's emitted by the sun get here?

They don't. Find me a picture of the Sun, or Moon from space that uses an off-the shelf camera, and can be shown not to be looking through Earths atmosphere. Maybe by the time they let me out, you'll have found one. NASA or Goddard or the ESA can't find me one, I asked. Maybe you will have better luck. Anyway, time for one last hoot before I turn myself in...

originally posted by: GaryN

Megapixels have nothing to do with light sensitivity. In fact, a smaller sensor with larger pixels would be better at capturing faint light.

Correct.

And yet you keep mentioning megapixels. Whether a camera has 2 MP, or 12 MP, doesn't bear on its light sensitivity.

Here's an image from the same camera as mine, with dark frame subtraction, but even without that, the Moon and planets are easily visible.
reductionism.net.seanic.net...

It's pretty close to what Curiosity has captured, in terms of light sensitivity. But of course the Moon is not visible like that from Mars, so the brightest and biggest objects visible from there are Phobos, Deimos, and Jupiter. Have you seen those images? Those objects have been captured quite well by Curiosity's camera.

So maybe the ISS crew needs to downgrade from those much newer Nikons to get some conjunction images?

Their Nikons have captured great images and videos of the Moon, the stars, the Milky Way, etc. but of course you keep banging on about it being through the Earth's atmosphere, even though the vast bulk of the atmosphere is a couple hundred kilometers below them, and we can see stars and other space objects fairly high above the Earth's limb.

Find me a picture of the Sun, or Moon from space that uses an off-the shelf camera, and can be shown not to be looking through Earths atmosphere.

upload.wikimedia.org...



As you can see in the astronaut's reflection, the Earth is directly behind the camera, meaning the Sun is almost directly above it.

Several here too taken with a Nikon DX2, including one showing the moon clearly above the Earth's atmosphere:

news.softpedia.com...

and goalpost move in 3..2..1...

a reply to: GaryN

Find me a picture of the Sun, or Moon from space that uses an off-the shelf camera, and can be shown not to be looking through Earths atmosphere.

be very carefull what you ask for :

theres the sun

source



deffo no " earth atmoshpere" on the moon

and just for completenes :

the earth and the moon - taken from lunar orbit - so absolutuly no earth atmosphere



as OBM said - goalposts move in 3 , 2 . 1 ............................

originally posted by: AthlonSavage
Actually thinking about this more, the ability to see stars is a relative effect to how much light is around us. For example during day we cant see stars. Therefore if the sun is pointing at them in direct site they wouldn't be able to see the stars to same effect. As they move further from sun the stars will come into view, I think a mathematical calculation could be done to show this. I would do the calc if I had time but im too absorbed on other research calcs right now so over to someone else.

I may be wrong, but I seem to remember reading a story about someone who either fell or climbed down a deep well during daylight and was able to see the stars...

originally posted by: JadeStar

Neither is lying.

They are both right. It depends on where the spacecraft (and the angle of it's window) was pointing and the time it was pointing that way.

On Earth's night side with no moon present (because it is behind you along with the Earth and the Sun) you would see stars.

Here's a challenge. Plot both Yuri Gagarin's orbit, in Celestia at the time he flew and then plot the flight of Apollo 11 to the Moon.

You'll see why one saw stars and the other didn't and be smarter in the process.

Just denying ignorance...

First I don't have Celestia running a friend's MacPro...

I do not understand then why Armstrong phrased it that way because he clearly went around to the far side of the Moon at least twice and he didn't add 'We saw brilliant stars on the farside of the Moon, but not in Cis-Lunar space _BECAUSE_...'

IOW, he looks a bit puzzled and not very sure of himself. You'd think that an astronaut would have given a semi-scientific explanation, such as "In Cis-Lunar space, the Sun was casting a glare on the windows of the capsule, both to and from the Moon".

He would have said something like "we tried to see stars with our eyes by getting behind a big boulder, but the glare off the Lunar surface, which has an albedo like asphalt was just unusually bright".

Instead he seems to have a limited or scripted comment which to the layperson seems counter-intuitive on the face of it.

a reply to: seattlerat


you may have read it but it doesnt make it true

originally posted by: ignorant_ape
a reply to: seattlerat


you may have read it but it doesnt make it true

You are correct this 'see stars in a well' is a myth.

www.snopes.com...

originally posted by: Maverick7


I do not understand then why Armstrong phrased it that way because he clearly went around to the far side of the Moon at least twice and he didn't add 'We saw brilliant stars on the farside of the Moon, but not in Cis-Lunar space _BECAUSE_...'

He was asked a specific question about the view from the lunar surface. He only mentioned cislunar space in passing.

IOW, he looks a bit puzzled and not very sure of himself.

In your opinion. My opinion says otherwise.

You'd think that an astronaut would have given a semi-scientific explanation, such as "In Cis-Lunar space, the Sun was casting a glare on the windows of the capsule, both to and from the Moon".

He would have said something like "we tried to see stars with our eyes by getting behind a big boulder, but the glare off the Lunar surface, which has an albedo like asphalt was just unusually bright".

Instead he seems to have a limited or scripted comment which to the layperson seems counter-intuitive on the face of it.

In your opinion.

Your main argument seems to be that because he didn't answer a question he wasn't asked then this makes the answer to the question he was asked incorrect. His not behaving in the way you think he should have behaved does not mean anything other than he is not you.

Armstrong navigated to the moon and back using stars. He specifically commented on the view of stars in cislunar space while he was in cislunar space. Which part of that is difficult?

originally posted by: ignorant_ape
a reply to: GaryN

Find me a picture of the Sun, or Moon from space that uses an off-the shelf camera, and can be shown not to be looking through Earths atmosphere.

be very carefull what you ask for :

theres the sun

source

For the sake of being accurate, the Sun in that image is fake, because the image is actually a mosaic of several photos, and none of them have the Sun in the frame (but plenty of lens flares).

Here's the mosaic using just the original images:

originally posted by: seattlerat

originally posted by: AthlonSavage
Actually thinking about this more, the ability to see stars is a relative effect to how much light is around us. For example during day we cant see stars. Therefore if the sun is pointing at them in direct site they wouldn't be able to see the stars to same effect. As they move further from sun the stars will come into view, I think a mathematical calculation could be done to show this. I would do the calc if I had time but im too absorbed on other research calcs right now so over to someone else.

I may be wrong, but I seem to remember reading a story about someone who either fell or climbed down a deep well during daylight and was able to see the stars...

They probably bumped their head.

a reply to: wildespace
Yes, here are a couple that they took of the Sun, but never through an ND filter, which is what is needed to make it look as it should appear. All the images show the Sun way bigger than it should using that lens, so is it just optics effects, or did the Sun really appear so large? IMO, what makes the Sun visible is the Lunar dust atmosphere.

www.lpi.usra.edu...
www.lpi.usra.edu...
Mystery of the Lunar Ionosphere
science.nasa.gov...


And here are a couple of quick graphics showing the geometry of viewing from the Cupola. The first shows the Earth as the inner circle, the smallcirle with the lines id the ISS with the line-of sight available from both the front window of the cupola and the angled windows that give a slightly increased angle. The second circle shows the approximate height of the denser atmosphere/ionosphere, and the outer circle is the extents of the exosphere where there is still matter, but much less dense. The long line of sight through the atmosphere when they view objects that still have the rim of the earth visible provides enough matter for the creation of light by interaction of the UV/EUV from the viewed object with the matter in the ionosphere, or rather the electrons of the atoms in that matter, as the process works better with bound rather than free electrons.
www3.telus.net...
The second image is just an enlargement of the ISS region. Grid squares are 1000 KM.
www3.telus.net...

originally posted by: GaryN
Yes, here are a couple that they took of the Sun, but never through an ND filter, which is what is needed to make it look as it should appear. All the images show the Sun way bigger than it should using that lens, so is it just optics effects,

Yes

or did the Sun really appear so large?

No

IMO, what makes the Sun visible is the Lunar dust atmosphere.

Your opinion is wrong.

The lunar dust atmosphere is tiny - there is not enough dust in it to produce the kind of effect you can see there. It is entirely a product of a camera pointing at the sun. You can find any number of photographs of showing objects much larger than they should be because of exposure times and camera optics and nothing to do with atmospheres. The video you link to contains an image of Venus that shows it far bigger than it is in reality. I have posted images taken of the moon during a lunar eclipse where it is apparently 3 times larger than it is in reality and not a single speck of dust or puff of air is involved.

Please buy a camera and learn how to use it.

originally posted by: GaryN
For the record, I learned my photography from a retired R.A.F aerial survey lance technician,

The RAF never had "lance technicians"....

I also bet they never taught you that stars from when you are in space cannot be seen!

I have lots of cameras, mostly film, my Coolpix 990, and D1x,

So why haven't you learn't how they and light etc. actually work?

I respect other people's opinion, I really do, but this.. this is LOL

OK so I didn't see GaryN's deleted post, but he I'm guessing he is claiming some sort of photographic expertise, and that he owns several cameras.

If GaryN has many cameras then I invite him to go out with a camera to the best place he can find to take photographs of the night sky and take some photographs.

He will learn that you don't just take photographs of the night sky like holiday snaps. You need to have the right settings on your camera and you need time. Those big swirls of stars you see that are really impressive? They can take hours, sometimes days to do. Really clear images with millions of pin sharp stars? They also take hours and hours with cameras mounted on tracking motors.

The conditions in space differ only that there is no atmosphere, but otherwise the technical difficulties remain the same: you need long exposures and sensitive receptors (whether that is the CCD or film), and a stable platform.

Here is a photograph of a small number of stars I took with my Canon 450D, resting on the roof of a car, on a clear night in a part of Scotland with very little light pollution.

Guess how long I had to stand there holding the camera still:



You can see stars in space, and you can photograph them, you just need the right conditions for the equipment you are using and this absolutely does not include the presence of an atmosphere.