What is Digg?81 Comments
- pauliewoll, on 10/12/2007, -0/+56It's a composite image, to illustrate the size of M31 in the sky relative to a familiar "landmark".
Agreed though, pretty impressive. - inactive, on 10/12/2007, -0/+28@ilyag:
Mere would be correct. In the scheme of things in outer space, Andromeda is in our galactic neighbourhood. - chriscooley, on 10/12/2007, -6/+26***** amazing
- EatingPie, on 10/12/2007, -3/+22This is a Composite image, not a "Capture" as the headline states. Andromeda itself has been magnified about 100x.
I realize most people understand this... just wanted to be clear because of the misleading headline.
-Pie - spect3r, on 10/12/2007, -0/+14Here is the picture of the original:
http://www.caelumobservatory.com/gallery/m31abtp.jpg - trogdor282, on 10/12/2007, -1/+15To put things in perspective, it would take the Enterprise 2400 years to reach Andromeda at warp 8 :-P
- arduenn, on 10/12/2007, -2/+15Wow, either the moon's very small, or M31 is very large. Dugg for being such an eye-opener. Yet, the composite looks very unnatural. I'd expect the moon to be highly over-exposed.
- zavigny, on 10/12/2007, -0/+12I've seen Andromeda many times under crystal clear skies without optical aid, and indeed, this is a close representation of how large it really appears. While it's not easy to see immediatly, after an hour or two of complete darkness to dialate your pupils to their maximum, you will likely have success. It appears to me as a large oval ball of soft cotton, with what I percieve as a slightly greenish tint, although the coloration could just be my imagination or an artifact of my visual system. I see it best by using "averted vision", where you look off to the side of the object by 10ยบ or so. It takes a bit of time and dedication, but the reward of seeing the farthest thing away that can be observed by the unaided eye is a tresure you can carry in your heart and mind for the rest of your life.
- gharding, on 10/12/2007, -1/+12I think I ordered this at Denny's last night..
- Alphabet, on 10/12/2007, -3/+14It's fake, but not really fake. If you place the moon and andromeda right next to each other, it would look like that. Unfortunately, in order to take a picture of the andromeda galaxy, you need to expose that patch of sky for months. The moon doesn't stand still in one place for months. So in order to compare the two, you have to take the moon and scale it accordingly, and then combine the two images.
And this is the result. - sardion2000, on 10/12/2007, -3/+13Fake != Composite.
- inactive, on 10/12/2007, -0/+10To all of you who are confused about what this is:
First of all, it IS showing the size comparison to the naked eye. YES, the Andromeda galaxy appears THAT large in the sky. You just don't see it with the naked eye because it is extremely dim. Those kinds of pictures are taken with very long camera exposures, hence the huge number of stars in the background.
YES, it is photoshopped. Because if you were to expose your camera long enough to see Andromeda like that, the Moon would totally overexpose your film or CCD. In addition, if you were to actually see the moon, Andromeda would be pretty hard to see in the same day because Andromeda is just *that* dim.
The purpose of this photo is to illustrate that the Andromeda galaxy actually appears that large in the sky and you don't need any advanced telescopes. All you need is a good camera and a remote location without light pollution. - inactive, on 10/12/2007, -0/+10Science damn you!
- JamesWilson, on 10/12/2007, -4/+14@ilyag: A light year is half the calories of a regular year.
- sardion2000, on 10/12/2007, -0/+8No it's more like 300,000+ light years across. I dont know the exact answer but it's a lot bigger then 10 light years across.
- inactive, on 10/12/2007, -0/+8very true about the rewarding part. the other rewarding thing is that this thing is 2,000,000 light years away. It's an incredible feeling, knowing how unbelievably fast light travels, to know that with your naked eye you're looking at something whose light took 2,000,000 years to reach you. You're seeing another galaxy as it existed 2,000,000 years ago.
The universe is amazing. - Screwy1138, on 10/12/2007, -2/+10I'm really impressed. I never knew Andromeda is so large in our skies. I wish we could actually see it better. Really nice picture.
- inactive, on 10/12/2007, -0/+8@Alphabet
basically correct explanation, but you don't need to for months. A good CCD will captureAndromeda like that with maybe a 3 to 5 minute exposure in a remote location without light pollution. - maehem, on 10/12/2007, -1/+7Satan put that galaxy there to lead you away from God.
/joke. Sorry, couldn't help myself. - andrewry, on 10/12/2007, -0/+6Durr, durr.
- inactive, on 10/12/2007, -0/+5If you go to a remote location, you should be able to see the brighter center of the galaxy as a dim fuzzy dot to the naked eye in the sky, if you know where to look. And if you set up a basic simple $200 newtonian telescope, you should be able to see just a hint of the shape around the center. I've done this much. But to see the whole galaxy that big though, you'll need a professional laboratory or a good CCD with a sky-tracking mount.
- sdbryan, on 10/12/2007, -1/+6No, according to the text Andromeda has not been magnified. That's the point of the picture. It is a very faint light source because of its great distance so the light intensity has been greatly "magnified" but the moon and galaxy are shown with the same angular resolution. Because Andromeda is only 2.5 million light years distant but has an extent on the order of 100,000 light years that makes its angular extent seven times as large as the moon.
The comment about Star Trek "technology" confuses the issue of the distance to Andromeda. Using actual rather than pretend physics it can be calculated that one could easily reach Andromeda during a human lifetime because of time dilation and lorentz contraction. This could be done with a starship capable of steady 1g acceleration. Here is a link to the calculations: http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html
You would age by 28 years during the journey and could return to Earth in another 28 years. Of course millions of years will have passed on Earth. That is what is called the Twin Paradox which isn't a paradox at all but rather a consequence of the geometry of the Minkowki spacetime we live in.
Although humans would be quite comfortable with steady 1g acceleration (it would perfectly simlate the gravity with which we are all familiar) it is worth noting that there is no propulsion system currently known that could provide it. Also there would be some very nasty consequences of traveling at such great velocity relative to the galaxies, the intergalactic medium, and the background cosmic microwave radiation. But all the way to Andromeda and back in little over 50 years plus the opportunity of traveling into Earth's future by millions of years. It would be one way but a potent time machine. That is with real physics rather than the storybook physics of Gene Roddenberry. - SoundJudgment, on 10/12/2007, -1/+6Hmmm... I don't see that spaceship ANYwhere in the shot. Nothing but a bunch of stars, planets and moons. Someone call up Tribune Entertainment and tell then to fire their production staff. Shoddy series promo. Wait... what year is this again??
- carbonetc, on 10/12/2007, -0/+4I'm with you guys. Sometimes I wonder what it really takes to inspire an iota of awe or marvel in the average Digger.
Jadedness FTW, I guess. - Falldog, on 10/12/2007, -1/+5APOD continues to be the win.
- Jugalator, on 10/12/2007, -0/+4Post your own digg stories instead of being off-topic.
- Calculusaurus, on 10/12/2007, -1/+5" The purpose of this image I guess is to show what it would look like if there was no light pollution..."
Light pollution or not, the human eye isn't a telescope. - JimDinger, on 10/12/2007, -0/+3Whole damn thing just makes a person sit back and think,doesnt it?
- GliTCH82, on 10/12/2007, -0/+3*****, that's pretty sad that even with our pretend technology we can only dream within our galaxy.
Fellas, we've got a lot of work to do. - inactive, on 10/12/2007, -1/+4or if you're canadian, "***** eh?"
- inactive, on 10/12/2007, -2/+5science be praised!
- D3koy, on 10/12/2007, -1/+4whoops... Sorry digg it down..
- D3koy, on 10/12/2007, -1/+4Who wants go to space now? Yeah, thats what I thought...I'll meet you on the ship
- lopla, on 10/12/2007, -2/+5"Awesome Capture"??? WTF? this is a photoshopped digital illustration of composite images. The fact someone thinks this is actually real is frightening.
- ghoppe, on 10/12/2007, -1/+4umm... yes it is showing the size comparison from the naked eye... read the caption.
I guess it's not so obvious, eh? :) - D3koy, on 10/12/2007, -2/+5Huh? Can someone explain this to me, I'm pretty sure I don't get it...
- ScooterDMan, on 10/12/2007, -0/+3great album!
- cliner, on 10/12/2007, -1/+4Shiny
- vhold, on 10/12/2007, -4/+6Why is this being buried? Ugh. The "Moon Over Andromeda" aspect it is effectively faked. And yes, it's a great picture, but to call it an "awesome capture" is simply wrong.
- maehem, on 10/12/2007, -0/+2Because it is. Try reading the article instead of just looking at the picture.
- alphgeek, on 10/12/2007, -0/+2It's showing the relative sizes of the moon and the Andromeda galaxy. The galaxy is big, but dim and therefore hard to see with the naked eye.
A telescope's main function isn't to magnify things, but to gather more photons so that dim objects become brighter. Anyone buying a home telescope should pretty much ignore the claims of '500x magnification' and select based on aperture (the diameter of the objective lens or mirror).
Even the biggest telescopes such as Keck rarely go beyond 800x magnification - their main function is to increase the light gathering power of the human eye from a few millimetres to 10 or more metres. - tmv32, on 10/12/2007, -0/+1Awesome!
- csrster, on 10/12/2007, -0/+1M31 is visible to the (experienced) naked eye even from significantly light-polluted sites, like a suburban back-garden. But I don't believe that the full extent of the galaxy as seen on this photo would be visible to the naked eye under any circumstances.
Incidentally, no one else seems to have pointed out that another reason why this image had to be made by compositing is that the path of the moon in the sky never takes it close to Andromeda. - sdbryan, on 10/12/2007, -0/+1Of course I meant to say "affect the evolution of culture" or "what effect it might have". One is a verb the other is a noun. Sorry for the sloppy typing.
- sdbryan, on 10/12/2007, -0/+1The physicist David Deutsch pointed out an interesting fact related to this picture. One of the points of this picture is that Andromeda, even though it is very close for a galaxy, is barely visible as a smudge to the unaided eye. If you were located at a "typical" point in the universe and looked at the sky you would see - nothing! Most of the places in the universe are nowhere near a planet, star or even a galaxy. Andromeda is only as visible as it is because it is in the same group as our galaxy, the Milky Way. So from most points in the universe an unaided eye would see no light whatsoever.
- gostars, on 10/12/2007, -0/+1Hubble's version
http://hubble.heim.at/images/M031-3_full.jpg
Hubble taking pics of little stuff inside Andromeda
http://hubblesite.org/gallery/album/search.php?method=and&format=normal&sort=score&config=picturealbum&restrict=entire_collection%2Fpr&exclude=&words=andromeda&Submit=Search+site - fearofcorners, on 10/12/2007, -0/+1@superpotential
..leaving the moon extremely overexposed, of course. It would be possible to capture the image using exposure bracketing and recombining the frames (hdr tone mapping, etc).
Also worth noting many (most?) of the images we see from space are heavily doctored and colourized anyway. Someone correct me if I'm wrong, but don't most stellar objects appear black and white from great distances? - ateoto, on 10/12/2007, -0/+1Yeah, everytime I pass over this now I think of that album. Good stuff.
- maehem, on 10/12/2007, -0/+1
Look at the Denny's breakfast menu for an explination.
http://www.dennys.com/en/page.asp?PID=1&ID=40 - alphgeek, on 10/12/2007, -1/+2The photo of Andromeda was taken using a relatively modest 127 mm refractor, the same as that pictured here:
http://www.company7.com/televue/telescopes/tv127.html
The scope is very high quality for an amateur refractor and goes for around $6-7 K US. A 300 mm reflector would easily produce similar image quality.
The total exposure time for this image was 22 hours, which is quite long for an amateur or semi-pro image.
Most likely, the image was built up of a composite of 4 exposures, one each for red, green and blue and a monochrome image for luminance. The Apogee U9000 camera is a 9 megapixel monochrome camera, pretty big by amateur standards. Camera cost is around $10K US. These are a far cry from your average 9 megapixel digital camera, make no mistake.
Factor in another $10K for tripod and mount suitable to do long-exposure photography of this standard. And maybe $5K for an observatory to hold it all, computers etc.
This quality of photo takes many years of experience to achieve.
Almost all astronomical images are heavily manipulated using image processing software such as photoshop. This is not to 'fake' the image, but to draw as much information as possible from it to allow analysis.
The moon image would likely be exposed for a fraction of a second using the same gear. -
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