A new old view of an old friend

By Phil Plait | January 19, 2011 5:05 am

[Yes, that title is correct. Bear with me.]

I’ve seen the Orion Nebula approximately… well, how many times? Let’s see… um, carry the two… yeah, a gazillion times. You have too, probably, since to the unaided eye it appears as a star in the dagger hanging below Orion’s famous belt*. I’ve also seen it with binoculars and through telescopes ranging in size from dimestore junkers to a one-meter on a mountaintop. And yet, every new picture of it reveals something interesting… like this spectacular shot does:

Yowza. Click to ennebulanate, or get the orionormous 4000 x 3800 version. Or you can treat yourself to the 142 Mb 9000 x 8600 pixel version!

First, some stats: this picture is a combination of five separate images from the red to the ultraviolet (that last colored violet, actually), including a filter that sees just the glow from warm hydrogen (colored red in this image). The telescope used was a 2.2 meter in Chile. The nebula is pretty big — the full Moon would just fit inside this image — so the detail on this is truly stunning.

The nebula is a vast cloud of gas, both atomic and molecular, and dust located about 1350 light years away. It’s one of the largest star forming factories in the Milky Way, and what you see here is well over 20 light years across.

For years I figured it was just a diffuse glowing thing in space, but it turns out to be more complicated than that. In reality, a lot of the nebula is actually a dark, dense molecular cloud — literally, composed of molecules like H2 (molecular hydrogen) and CO (carbon monoxide). This cloud is actually far, far larger than what you see in this image, perhaps 20 times the width! But it’s dark, so we don’t see it in visible light… and what we’re seeing in this picture is not really a free-floating gas cloud, but a cavity in the wall of the denser dark cloud.

Stars are being born inside that cloud. Some of them are very massive, hot, and bright. They blast out a fierce stellar wind, like the solar wind but far more powerful. They also emit a fierce flood of ultraviolet photons. Together, these two forces erode away at the material of the cloud, breaking apart the molecules into their constituent atoms, ionizing them, and causing them to glow. It so happens that some of these stars were born near the side of this cloud, so when they ate away the insides of the cloud it caused a blister in the side which burst open.

You can actually see that in this image! The bulk of the colorful nebula, from the upper left on down, is actually gas inside this cavity set aglow. The far wall is opaque and dark, so you don’t see it here. But you can get a sense of the bubble-like nature of the nebula.

I always get a bit of thrill when I see a picture that makes the concave nature of the nebula apparent. It’s not clear from some photographs, depending on the filters used, but I can see it in this one. And an interesting thing; these weren’t new observations! Igor Chekalin found several images of the nebula in the European Southern Observatory archives as part of their Hidden Treasures contest, and put them together to create this new image.

See? My title really was correct.

And oh, about that contest; amazingly, this image didn’t win. What did? An image of another nebula in Orion called M78… put together by Igor Chekalin!

Image credit: ESO and Igor Chekalin

* My roommate in grad school questioned the taxonomy of it being a "dagger", ifyouknowwhatImean winkwinknudgenudge saynomore.

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (35)

Links to this Post

  1. Nebular, Dude! | Atheism From Below | July 15, 2011
  1. Gary

    What an absolutely beautiful image. Who needs a god to inspire awe when we have the very universe we live in?

  2. LittleJim

    That is dark matter, isn’t it? It’s just that space, you see, is black. And the thing about soot and carbon and dust and stuff is that it’s black. So unless you have a light source of some sort around, you can’t see it!

    Is that about it?

  3. LittleJim

    The thing about the Orion Nebula actually being 20 times the width of what we can actually see, is what I meant, sorry. Probably should have pointed that out.

  4. Nadim

    The photo looks pretty spectacular! It’s amazing just how much detail one can get the further they look into the Orion Nebula. :)
    Another note, what is it with the strange rings around the red stars?

  5. I see Mary holding baby Jesus!

  6. CameronSS

    Dangit, these astronomers need to learn to produce images that aren’t so square. I can’t make a desktop background without cutting off purty bits, because it’s all purty bits.

  7. Messier Tidy Upper

    Splendid image. Magnificent.

    Thanks Igor Chekalin & the BA. :-)

    One minor question : 1350 light years away – is that new, revised distance estimate for it?

    I’d previously thought Messier 42 (the Orion Nebula) was about *1,500* light years away although figures have been known to change depending on time and source. Or maybe I’m just confusing M42 with Orion’s “belt stars” (going from Taurus to Canis Majoris facing sides here) Mintaka (Delta Orionis), Alnilam (Epsilon Ori.) & Alnitak (Zeta Ori.) instead?

  8. BillZBub

    @AndyD: I see it too! However, I think it is baby Space Jesus because those eyes are a little too big to be fully human.

  9. CameronSS (#6): The first link, right above the picture, has wallpaper versions on it.

  10. Nadim (#4): I almost wrote about those rings around stars, but couldn’t find a good place to put it. :) They are internal reflections inside the telescope or detector. The light from a bright star bounces around and makes those rings. We saw them a lot in our Hubble images. Lines drawn from the stars through the reflections usually converge on one spot in the image, which is due to the way the optics align in the image, and that’s one way to know you’re dealing with a “ghost” image.

  11. Messier Tidy Upper

    Incidentally, on a tenuously related note (it *is* in Orion after all & figure some readers may be interested) – did folks know about this very faint (6th mag.) but still unaided eye visible (in a very dark sky) star :


    HR 1988 a G4 IV yellow subgiant in Orion between Betelgeux and Alnitak that boasts not one but two confirmed exoplanets? Although it seems one of them might well be a brown dwarf instead? :-)

  12. Steviegene

    There are some who say that the throne of God is hidden behind this curtain of dark matter. The awe inspired by the universe is magnified for me by believing there is a Creator behind it all. I appreciate the wide perspectives of both Mr. Plait and all who comment here because it helps me balance my own belief and doubt while getting a sense of yours. Thanks for the pictures, thanks for the viewpoints.

  13. Calli Arcale

    Okay, new desktop background. Totally. ūüėČ

  14. Paul Clapham

    Not a dagger but a nudgenudgewinkwink? Now consider how Orion appears in the southern hemisphere…

  15. I was looking at this nebula with my new telscope the other day. :) Trying out different filters and such. The only complaint I have is that I didn’t get automatic drives for my telescope, so I have to keep manually adjusting (especially when I have the higher magnification eyepeices in and have a narrow fied of view). I wonder if I can get that gawd character to stop the earth from spinning? Probably not since I am not intent on genocide…

  16. Please, this is not an either-or problem (i.e. Creator or no Creator). Since we know absolutely nothing it would be like my dogs debating who or what or how or why their dinner bowls are full of food every night, or how when they get in the car and then get out they are somewhere new.

    I think “awe” is the appropriate all inclusive response and a humility that makes our tiny tiny tiny minded opinions laughable.

  17. Gary Ansorge

    “They blast out a fierce stellar wind, like the solar wind but far more powerful. They also emit a fierce flood of ultraviolet photons. ”

    This does not sound particularly conducive to life(as we know it). The universe seems barely TOLERANT of life, rather than inclined toward producing such.

    The following link is about the positive value of the cosmological constant, which if a god wanted to “fine tune” for the maximum amount of life, should be slightly negative.

    I guess God actually said “Let there be,,,Oops,,,dang!”


    Gary 7

  18. @ Jill (#16), I would contend that we know a great deal about specific claims made regarding specific creators. We are quite certian that the world wasn’t made in 6 days, or that the planet is the corpse of some titan, or floating on the back of a turtle. It’s like the dog proclaiming that the food bowl is filled by a thunderclap that magically materializes the food. Other dogs can see their owners pour their kibbles in, thus falsifying the thunderclap story.

    Now, if you go to the realm of a Deist approach, then I would agree with you. :) And I am saying that as a strong atheist. <3

  19. One of these days, I’m going to print out a few of these super-large space photos and paper my ceilings with them. A 9000 x 8600 pixel image could make a 65.33 inch by 57.33 inch poster at 150dpi. Drop the dpi to 100 and you could increase the poster size to 98×86. One of these might fit my office ceiling nicely. Then I could be working under the stars. (Or nebula as the case may be.)

  20. Chris A.

    @LittleJim (#2 & #3):
    “That is dark matter, isn’t it?”

    No. Because we can detect this stuff in other wavelengths. The areas of Orion that appear dark in visible wavelengths are positively aglow in the infrared.

    Dark matter, whatever it is, only reveals itself through its gravitational effects–we haven’t been able to measure its interaction with electromagnetic energy, if any, so far.

  21. DigitalAxis

    Bah, what happened to the 16:10 and 16:9 wallpapers? This is 2011, we need 2560×1600 at the least.

    I actually would have to agree with the judges; M78 is not quite as iconic as M42, but the three-dimensionality of that picture is gorgeous.

  22. The Beer

    Its funny to think that if our solar system were in there, it would probably include a few of our local stars as well.

    Can you imagine if we were at least close to something like that? I wonder how our perspective on astronomy would have dveloped!

  23. Eugene

    Has anyone actually tried making a computer model of the basic shape of a nebula like this one? I bet it would look pretty cool. Plus, even though you can see the cavity pretty clearly, it’s hard to wrap my head around the idea that there’s an outer shell I can’t see.

  24. mike burkhart

    This is one of my favorte sight in the winter sky this and the Pledies.

  25. Michel

    Since so many stars are born in M42 are we seeing the start of a cluster?

  26. CameronSS

    Phil: Thanks, I should actually try clicking links sometime. Still requires cropping, though, because I need widescreen and widerscreen. I guess I’ll just have to suck it up and chop something off.

  27. QuietDesperation

    Has anyone ever rendered an image of what it would look like inside one of these nebulae? I know we get fooled by the long exposures of pictures like this, and the nebula would be very diffuse up close, but it would still be interesting to see a scientifically accurate rendering instead of the blinding, glowy technicolor clouds we see in the moovies.

  28. Ross

    This is one instance where some 3d visualization would go a long way to helping us non-astronomers comprehend the shapes and features Phil describes.

  29. Crudely Wrott

    @18, Larian, thanks for reminding me that creation stories, like tribes and nomads and fledgling societies and even fairly sophisticated societies that accept them, are pretty much a dime a dozen. From a historical perspective, of course.
    While horrific acts that occurred in the past are disturbing and mostly recalled through a veil of retelling and allegory, when they happen now, nearby, they can incite such as we see ourselves presently saddled with. As a result of giving tacit approval to at least one creation story (if more than one then one is considered correct and any others are granted lip service), privilege is extended in an obviously biased way to an unremarkable few in an unconstitutional way.
    Not only that, the mere scent of such assumptions should put everyone on guard; it is a familiar spoor.
    Keep on truckin’!

    @22, The Beer, truth is, the Orion Nebula is practically rubbing elbows with us. Look at the Hubble Deep Field pictures and remind yourself that each of the myriad galaxies you see contain a similar myriad of nebulae . . . that’s the wide view.
    To resolve the solar system your field of view is necessarily restricted to a very small portion of what can be seen. I picture it as the difference between looking at the setting sun and feeling part of a larger scheme and then looking down at a spider trying to hide under your foot and feeling like part of a smaller scheme.
    Which just makes it deeper.

    Thanks, Phil. You really deliver.

  30. Cosmonut

    Why do these posts always seem to provoke bickering about God?

    Our Universe is magnificent and awe-inspiring.
    If your appreciation of it is heightened by believing in a Deistic “Something-Beyond-It-All”, great !
    If just contemplating the Universe is good enough for you, that’s great too.

    Why fight?

  31. Astro Ash!!

    I’m not atheist, but I think Phil Plait is one of the most magnificant astronomer that ever lived!!! I think you are spectacular just like the picture above! I believe in God, but I know just because someone is atheist does not mean they are a bad person and I just to say thanks for being a good roimodel for me and my great story i am writing. Never give up-Ashlynn

  32. For Ross, or anyone else wanting a 3D visualization: I recommend seeing the recent Imax 3D Space Shuttle movie. It includes a trip to (and into, and through) the Orion Nebula that was constructed in 3D from various Hubble photographs (and some conjecture obviously), and it’s simply stunning.

  33. Nigel Depledge
  34. #5 AndyD:
    That Jesus guy gets around a bit, doesn’t he? Just a few years ago, he was in the Eagle Nebula, and now…
    Cue God Squad loony headlines about “Mary and Jesus are alive in the Orion Nebula!”…


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