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Are there*any* large, pretty structures in space that can be seen with the naked eye?


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Following on from the thread looking at "The Manifesto of the Committee to Abolish Outer Space":

Without re-hashing what that weird "manifesto" is all about...

Things like nebulae are often presented in literature using imagery from various instruments that record yet more various sensory data which is used to produce so-called "false-colour" picutures that use light enhancement, non-visible spectra etc that give these wonderfully colourful and impressive images of huge, light-year scale objects.

In reality, if you were an astronaut in deep space and you stuck you head out of the ship (in a suit, natch), viewing with the naked eye, these objects would be nigh-invisible, due to the type and intensity of their emissions and generally diffuse nature.

Are there *any* large structures that could be viewed with the naked eye in space? If you were, say 100,000 light years outside of the milky way (approx 1 milky way diameter) would it appear as a blazing spiral? Or something more mundane? Or would it be almost invisible?

Is it possible for there to exist large cloud/dust formations that are emissive enough in the visible spectrum to be visible - from a distance that they would subtend a large-ish portion of the "sky"?

I know that there are visible things, obviously, if you go close enough to them you can view things like planets and asteroids - black hole accretion discs would be quite impressive to see, though I'm not sure what the safe distance is from one of those (referring to hard radiation from the disc, not the hole's gravity) and if you could get close enough to it that it would just be a point of light.

I'm looking for things of a more "grand" scale I guess, could you ever view a galaxy cluster for instance.

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Nebulae and star clusters could be very visible under the right conditions, we can see quite a few of them with the naked eye, although they won't be quite as dramatic as many of the false light pictures that we often see published.

The Milky Way too is quite visible on the night sky when you're in an area with low light pollution, even with the detrimental effects of the atmosphere. So from space, at an angle away from the galactic plane and at about the same distance away from the center, the spiral should be quite a spectacle to behold against the dark of the rest of space. Especially the core.

A closely-knit group of galaxies, like our local group, is likely the biggest structure of sorts that we could visibly make out.

Seeing a galaxy cluster with the naked eye is highly unlikely. There are only a few galaxies that we can see with the naked eye as it is, and I think all of them are in the local group. Galaxy density in a cluster is also far lower than star density in a galaxy, even allowing for the scale difference: clusters are usually about 100-1000 galaxies, whereas most galaxies hold billions of stars concentrated in a much smaller volume.

In most clusters, the clustering doesn't even become apparent until one 'zooms out' several orders of magnitude, at which distance all sources of visible light in galaxies have become too faint to spot with the naked eye.

So I'd say a tight group of galaxies is about as grand as we can expect to see out there.

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The Moon.



Milky Way Dusts.

Andromeda Galaxy.


I don't know what the manifesto is talking anyway. We certainly know it's there - the only thing I can't imagine about these people is to explain an alternative story, where did that few story high explosive - rockets - gone ? Can't stand their weirdness...

Back on topic : they'll be very hard to look at. Only skilled observer will be able to discern them than feeling of seeing faint reflection, if you're in outer space.

Edited by YNM
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7 minutes ago, tater said:

I'd second the Milky Way. Anyone living in an urban area who has never been to a truly dark sky tends to be pretty gobsmacked when they see what the sky actually looks like at night.

I live in London but am from up North, when I occasionally visit my folks back home, if you look out of the window of the train (assuming its night of course) as you travel out of london and further North, you can literally watch the stars coming out. You can see like 10 stars from London... :(

Edited by p1t1o
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Orion Nebula is visible to the naked eye. To my eye the nebula looks like a faint star halfway between the belt of Orion and the stars Saiph and Rigel.

Also the Pleiades cluster is easily visible to spot near the Taurus constellation; is appears as a fuzzy blue cloud with five dim blue stars.

Edited by Exploro
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I'd be speechless if I got to see that.

If you were outside the galactic plane, you could probably make out the spiral arms, and be able to see a few neighbors. It wouldn't ever be as spectacular as a long-exposure of the same view, but it would certainly be a sight to behold. Anything much farther than that and the light is too dim to make out at all.

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When trying to see extended objects, what counts is surface brightness. Getting closer to something doesn't increase its surface brightness, because you see it spread over a larger angular size. That may seem counterintuitive, but it really shouldn't - an ordinary object here on Earth looks just as light when it's up close or far away. Looking at something through a telescope can't increase surface brightness either.

What this means is that if you can't see an apparently-large nebula from dark skies on Earth, you can't see it with your eyes *anywhere*. So stuff like the California Nebula or Banard's Loop is not going to be visible. The Orion Nebula will be visible, but not especially colourful.

As for candidates for what *would* look bright and spectacular, well a few spring to mind. Planetary nebulae for a start. They're very compact by nebula standards, and appear too small to see with the naked-eye from Earth but can have quite high surface brightness and through a telescope visible colours.

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Also, does seeing them from telescopes with bare eye (no artificial detector) counts ? If that counts, pretty much all object can be seen...

Good "Cricket Wars" joke there XD fits the title !

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