pillars

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dannyd

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Just wondering - were one to be on a planet in one of those astounding hydrogen pillars - what would the night and daytime sky look like? dannyd
 
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dannyd

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I'm sorry I was so vague - I mean of course those awesome gaseous pillars photographed by Hubble a decade ago in the Eagle Nebula. thanks -dannyd
 
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newtonian

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dannyd - perhaps quite dark - I will detail my reasons soon.
 
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newtonian

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dannyd - That would be the pillars of creation - very awesome hubble photo!<br /><br />Early earth was apparently very dark - note that it is not just hydrogen in those 'pillars.' It is also dust.<br /><br />My specialty is Biblical cosmology, which relates to your question:<br /><br />I will add, of course, scientific reasons for the following which would likely be true for planets embedded within such hydrogen and dust (etc.) clouds (pillars):<br /><br />(Genesis 1:2) . . .Now the earth proved to be formless and waste and there was darkness upon the surface of [the] watery deep; . . .<br /><br />This was, of course, after the creation of earth (Genesis 1:1). Apparently, it was not just water (more hydrogen than oxygen - H2O) that was accreted by early earth, but also dust that caused darkness on the formless (no landforms) early earth.<br /><br />There were clouds causing darkness and gloom (compare Venus today):<br /><br />(Job 38:4) 4 Where did you happen to be when I founded the earth? Tell [me], if you do know understanding.<br />(Job 38:9) 9 When I put the cloud as its garment And thick gloom as its swaddling band,<br /><br />Likely planets in the Eagle Nebulae would tend to by enshrouded in similar 'swaddling bands," accretion bands including the abundant dust in these hydrogen pillars. <br /><br />Is water also abundant in those pillars?<br /><br />Back to darkness on planets early in accretion stages:<br /><br />(2 Peter 3:5) . . .an earth standing compactly out of water and in the midst of water . . .<br /><br />This was right before the last condensation catastrophe on earth - involving accretion and also cooling of the planetary surface.<br /><br />By this time the accreting water had already gone from translucent (compare Venus) to transparent.<br /><br />Much earlier, light reached the surface of the earth:<br /><br />(Genesis 1:3) 3 And God proceeded to say: “Let light come to be.” Then there came to be light.<br /><br />It was at this point that the daytime sky became translucen
 
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doubletruncation

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I think it depends on how deeply embedded you'd be in one of the pillars. The regions are dense enough to block out light from background stars (I don't know off-hand a numerical estimate for the extinction though) so if you were deep in the middle of one of the things then it'd be really rather dark (as Newtonian mentioned) at least in the sense that you wouldn't see many (if any) stars in your sky. But the back-scattering of light from your star off the dust around you would probably lead to a brighter night sky background than you would see outside of the Earth's atmosphere. Outside of one of the actual pillars I think you'd see very large bands across the sky where no (or few) stars would appear to be present. I don't know if you'd be able to see the nebular emission very clearly with your naked eye, you'd be closer to it so you'd gain by ~1/r^2 but it'd appear to be spread over a larger area which causes you to lose by ~r^2. It's an interesting question though. <div class="Discussion_UserSignature"> </div>
 
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qso1

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I doubt you would even know it if you were inside the pillars. Even if you could see them they would be too large within your field of view to realize what they are structurally. The night sky might be more the color of the pillars but I suspect you would not see them at all.<br /><br />The real vantage point is to be within maybe 5-50 Ly distance from the pillars where they could be seen towering into the night sky in one direction. I'd have to do up an image to illustrate what I mean here but if you've seen artists illustrations of starry skies with huge galaxies in them as seen from hypothetical worlds, the pillars would be a similar situation. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>
 
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dannyd

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thanks people - qso, yeah, that's the answer I was hoping for. Can you imagine looking up and seeing those stupendous structures as part of the skyscape? As incredible as our sky is I suspect it is rather pedestrian compared to views from other planets out there. -dannyd
 
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CalliArcale

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One thing to bear in mind is that the Hubble photos are long exposures. Even close up they may not be as spectacular as you hope. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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agnau

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Did they adjust the photos for Red Shift or is that the raw coloring received by hubble in a specific spectrum? <br /><br />If that is shifted toward visable for example, it is possible nothing would be seen much closer up.
 
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doubletruncation

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It isn't really corrected for redshift in any sense (the radial velocity of these would not be very large) and the filters used for the classic 1995 shot are all in the optical, but they are narrow-band filters designed to detect light in a very narrow frequency range from atomic line emission (which is what's interesting to look at from a scientific point of view). The filters they used were 502 nm, 656 nm, 673 nm. The colors in that sense are probably not very representative of what you would see if you could see it with your naked eye. Also note that the nebula looks different depending on what filters you use, the coloring of the more recent ACS image of the eagle nebula looks pretty different from the classic 1995 image. See for example: http://heritage.stsci.edu/2005/12b/supplemental.html<br /><br />And as Calli mentioned, these are pretty long exposures (the 656 nm image is over 18 minutes for example) using a 2.4 meter mirror (i.e. imagine a 2.4 meter eyeball). The eagle nebula is about 15 light years across, so if we were ~50 light years away it it would be about 17 degree across (comparable to the width of the milky way), but I don't think it would look much brighter. We're about 7000 ly away, so the total brightness would be up by a factor of (7000/50)^2 ~ 20000, but the area that that light would be coming from would also be up by a similar factor of 20000, so the surface brightness would approximately remain the same, meaning you'd still need Hubble to stare at it for 18 minutes to get the same number of counts per pixel in your image, and you wouldn't be able to see the emission from it with your naked eye. I think what you would be able to notice though is the extinction, so you would probably be able to see it in silhouette against the background stars, in the same way that you can see the dust lanes in the plane of the galaxy. <div class="Discussion_UserSignature"> </div>
 
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newtonian

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doubletruncation - Thank you for the link. <br /><br />The Eagle nebulae 2005 shot is not only different from the Hubble 1995 shot in color - but also in shape.<br /><br />Is it changing shape that fast?<br /><br />The extinction (of light) is what I was posting on, in effect. Am I wrong - or is it as I thought that we cannot see through the dust clouds such that a planet within the thicker portion would also not be able to see out to our area, etc.?
 
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doubletruncation

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It's a different field of view, as you can see in the top image (which is a ground-based image). Also they used different filters, and since the line emission from different atomic species is distributed differently you'll see something slightly different if you use different filters.<br /><br /><font color="yellow">The extinction (of light) is what I was posting on, in effect. Am I wrong - or is it as I thought that we cannot see through the dust clouds such that a planet within the thicker portion would also not be able to see out to our area, etc.?</font><br /><br />I think that's probably true, yes. <br /><br /> <div class="Discussion_UserSignature"> </div>
 
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newtonian

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doubletruncation - By a different field of view, do you mean we (earth, solar system) have moved suffiently to change the appearance of the Eagle Nebulae? Is it that close?
 
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doubletruncation

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No, I just mean the 1995 and 2004 pictures aren't of exactly the same portions of the Eagle Nebula. The two green boxes on the first image of the link shows the fields of the ACS (2004) and WFPC2 (1995) pictures within the larger context of the Eagle Nebula. <div class="Discussion_UserSignature"> </div>
 
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