M81, up close and personal

By Phil Plait | May 29, 2007 9:27 am

What is it about grand design spiral galaxies? Is it their symmetry, their grace, the sweeping majesty of the spiral arms?

Beats me. But they sure are pretty!

The image above is a new release from Hubble, and shows the lovely M81, a spiral galaxy just 12 million light years away. That’s close, as cosmic neighborhoods go; only a handful of big galaxies are closer. This means that M81 is pretty well studied, and Hubble images can be very detailed. In fact, in this observation, individual stars in M81 can be seen! Click it to get higher-res version, including, if you dare, a 23,000 x 15,000 pixel version that tips the scale at 700 Mb!

M81 is interesting. Despite its beautiful symmetry, it had a close encounter with another, somewhat smaller galaxy named M82 about 300 million years ago. They are still fairly close together:

They are about a degree apart, and easily spotted together by northern hemisphere observers using binoculars — some sharp-eyed folks can even see them with their unaided eyes, in fact. If you look at M82 (click it for a bigger image) you can see that it’s a mess. When galaxies pass each other, clouds of gas and dust can be disturbed or collide, which then triggers star formation. M82 is called a “starburst galaxy” because of the vast number of stars being born in it. The weird reddish tendrils are actually gas streamers being blown out by the most massive and luminous of the newly formed stars in the galaxy.

M81 holds a special place for me, too. Back in 1993, a star in the galaxy blew up, and it was named SN1993j (the 10th supernova seen that year). I was in grad school, and we took some students out to the 1-meter ‘scope to take a look. I had looked up what the core of the galaxy looked like so I’d be familiar with it when I saw it. Near the core are two bright stars — actually stars in our Galaxy — seen superposed on the more distant spiral. But when I looked through the eyepiece, I saw a third star, about equal in brightness, and I knew right away it was the supernova.

I can still remember the awe I felt, the thrill, hunched over the eyepiece of the telescope. I had spent two weeks up in that same dome getting my Masters degree observations, but that was using a CCD, an electronic detector which saved images directly to a hard drive. This was different. I was seeing the supernova directly, myself. The photons I was seeing left that galaxy 12 million years previously, traveled across intergalactic space, were reflected by a mirror, and sent shooting into my own eye. Somehow, those packets of energy — so weak individually that they couldn’t ruffle a mosquito’s wing — were then converted into electric impulses by my eye and brain, and transformed once again into the sense of the numinous.

When those photons left that galaxy, there were no beings on Earth capable of understanding them. But during the intervening eons, our brains and eyes evolved, our imagination grew, and we became a species that can not only look up and wonder, but collect the feeble information that had previously fallen unheeded onto the ground and turn it into understanding.

Maybe that’s not what everyone sees when they look at the image of M81, but it’s what I see. And maybe, now, when you look at it, you can get a taste of it too.


Comments (50)

  1. Stupendous Man

    Phil, you are nothing if not poetic. Very nice post. Thank you.

  2. Stark

    Phil, It’s posts like these that rekindle my love of astronomy. Living in a city it’s all too easy to not notice the night sky – the glare of street lights washes it out to the point of being almost a blank canvas – and I sometimes forget the wonder of looking into that sky and realizing that it is the history of our universe we are looking at. Prose like yours wakes up that feeling that is lost to light pollution.

    Now, if you’ll excuse me – I need to go make a reservation for my favorite dark-sky camprgound for the coming weeked.

    Thanks for the inspiration to get me off my lazy butt and out into our universe!

  3. Betsy Hutchins

    That is one of the most moving observations I have heard since I learned from Carl Sagan so long ago, that we are made of star stuff. That idea is nothing to today’s interested people–but when I first learned about it, the life of my mind was changed. And the idea that we had to evolve to where we are, as that light was coming to us–and then the idea that we met at the right time is hairs on the back of the neck moving.

    By the way, once you understand the ecology of the universe somewhat (as the above) it is easy to be an athiest–we are one with all and always will be.

  4. bigjohn

    Who needs religion? Just look through a telescope(or just look at nature in any way at all for that matter) with just a bit of understanding about what you are seeing and the grandeur of it inspires a spiritual awe. With no understanding or interest in understanding we have religion.

    Nice story, Phil.

  5. Miranda

    I had a similar experience when I first saw M31, with the naked eye no less! A whole other galaxy, 2.2 million light years away and I could SEE it. It was fantastic! It was the first time I felt I could really understand how big the universe must be and how insignificant we really are. No matter what foolhardy things we do, the universe will prevail… and with it, so will we, in some fashion.

    Since that time, it has remained my personal favourite. The Hubble Deep Fields are awe-inspiring as well, for somewhat similar reasons.

  6. Grand Lunar

    I’m with you, BigJohn.

    Though I haven’t spotted galaxies in my puny ‘scope, I’m still held in awe looking at objects through it. Even the moon, a short trip away (relatively) holds me in awe, looking at this place that holds 4 and a half billion years of history in in. And then the planets, with their own weirdness, amaze me too.
    And then there are the stars themselves! Looking at the reddish hue of Betelgeuse, or the glare of Siruis, or the jewel-like collection of the Pleadies makes me glad I’m into astronomy to see this stuff.

  7. Rowsdower

    I agree with the beauty and grandeur that is contained in the picture, but I have a further observation. In looking at the full resolution picture, I noticed that there must be literally hundreds of other galaxies in the background of that picture. I didn’t go through it with a fine-toothed comb, but in the little bit I looked at I could have counted a couple of dozen. I kept going, “There’s another galaxy! And another! And another!” And even though the resolution of the other galaxies wasn’t great, it gave me further awe because as prevalent as this one galaxy is, there are hundreds more in that same field of view.

    Which brings up the question: Has anybody counted the galaxies in that picture and if so, how many are there?

  8. CloudFrog

    Hey Phil…this has nothing to do with your post, I just thought you might be interested…

    I attended the Creation Museum on opening day, and it was FANTASTIC! I couldn’t believe how much fun it was! I bit my tongue the whole way through the museum ($20 to get in! $5 off if you became a member, which I did), and even through the better part of the Planetarium bit (an additional $6), but towards the end I couldn’t do it any longer. They mentioned that the observable universe is 11.5 billion light-years in radius (although, I’m unsure if that number is correct), and they made a big deal about how a light year was distance, not time (even though it’s really both). Finally, the guy made the point that because of the gravitational pull that large objects in space have on light, it’s possible for us to observe objects that far away even though they are only 6,000 years old because of some temporal fiction they came up with. I couldn’t hold back anymore. The laughs just poured out. When a museum operator asked what was so funny, I had to mention… “Light has a set speed, and we can observe that speed. It’s about 186,000 miles per second. You’re suggesting that somehow because of gravity, light is traveling WAY faster than that. You’re off by a factor of 2 million. That’s like me saying the sun has the diameter of Flordia.”

    No one could clear that one up for me.

    I’m going back Thursday (I think I’m going to get an annual pass!), and I’m going to take a camera and a pencil and pad to try and find all of the factual mistakes, mistruths, psuedo-sciences and flat out lies. If you’re interested, I’ll let you know when and where I upload them.

    Oh, and by the way….science came from the devil in the form of a talking snake giving apples away.

  9. Jim C.

    Same thing here Rowsdowser. My wife and I made a game of finding them. We gave up at 79.

  10. Bad Astronomer:

    some sharp-eyed folks can even see them with their unaided eyes, in fact

    I know that some folks in the legendary dark of the Nebraska Star Party have seen M81, but has anyone actually seen M82? I’d love to see a documented report of that.

    Grand Lunar:

    Though I haven’t spotted galaxies in my puny ’scope, I’m still held in awe looking at objects through it.

    M82 (the weird one) is a surprisingly good target for smaller scopes. Though it’s not apparent from the photo above, there is a region of mottled light and dark areas near the center. This region is much more prominent than most other galaxies’ features. You might be able to see it with a 4 to 6 inch telescope if you have dark skies to play with.

  11. hale_bopp

    I had a real goosebump moment when I first saw Einstein’s Cross visually. We had a big scope and a crystal clear night. Really small smudges of light that would not impress anyone, except for the fact that you are looking at something 8 billion light years away (according to Wikipedia). This light has been traveling longer than the Earth has existed! Talk about a Wow! moment.


  12. Arthur Maruyama

    Cool post, Phil. Thanks for your insight and your personal touch.

    Here is something that is peripherally related (since you did write of the interaction between M81 and M82):
    These are a set of movies showing galactic interactions, compressing billions of years into minutes. While most of these are theoretical constructs, Future Sky and Spiral Metamorphosis show the interaction between the Milky Way and Andromeda Galaxies. I especially like Future Sky since it shows what might happen from the Sun’s point-of-view.

    Do note that the files are large to huge (from tens to hundreds of MBs) so they will take a while to download and play. The musical accompanyment may not be to everyone’s taste, but I didn’t mind much.

    Since that site has been up for a while, do forgive me if someone else has posted it. I did try a search on “galaxydynamics” and it returned no hits.

  13. ::applause::

    Terrific post, Phil.

  14. John

    Beautiful. Describing both the image and your post.

  15. Gaijin51

    CloudFrog: You really paid good money to see that stuff? Why support them at all? Last time I checked pointing out factual errors has no effect on these people. Truth is irrelevant to them; it’s what they want to believe that matters.

  16. Just a small nit to pick, but in 12 million years our eyes haven’t evolved that much- they aren’t that different from gorilla or orangutang eyes. How our brains interperet the light that reaches them, though…

  17. DenverAstro

    Very interesting. I use M81 and M82 as a guage almost every time I go out observing to check for sky transparency and background contrast. Since with a low power eyepiece you can usually see both in the same field and since one is significantly brighter than the other, they make a great subject for checking how easily I will be able to observe other simular magnitudes from our dark sky location. Of course there are times when they appear in the sky right over the Denver light dome. Thats when I use other deep sky objects. However, 81 and 82 are a couple of my favorites. On the other side of the sky is my real number 1 fave galaxy, M104, the Sombrero. On nights of really good seeing, I can clearly see the central dark lane of this wonderful galaxy. As a matter of fact, I was looking at it a few weeks ago at the last new moon. This is really the best time of year to look at the whole Virgo cluster because it is up high enough after sunset to really get a good look around the whole area.
    I have always felt a bit humbled by the awesome size and depth of our universe. If it was a created thing, I would love to chat with the critter that done it. I’m pretty sure tho, that some day we will have definative answers as to what caused the whole damn thing and wont have anything to do with a big hairy cosmic muffin.

  18. CR

    The last two paragraphs in your post (and I liked the WHOLE post) were fantastic, and really conveyed the sense of wonder and awe all of us should feel, if we bother to look beyond ourselves for just a moment and ponder…

  19. Wow, I am so gonna download that huge TIF when I am at home! Can’t wait to see the details on that one. I am not even sure if my computer can handle that. Nice post. Space has always been a place for me where I can wander around in with my thoughts, and think about things that have been, things that are, and things that will be!

  20. Gilles

    Galaxies make me feel sad, they look too much like water going down a drain, dragging all eventual life forms towards the black hole at the center.

  21. The barber of civility

    Geez, Gilles! It looks like you need a new perspective on things!

    Consider that maybe, just maybe, the stuff that gets dragged in will eventually make up something more profound than what we have now.

    Try to find the good stuff, instead of seeing the “bad”. Reread Phil’s post. It’s all about the positive.

  22. Thanks for those words Phil.
    Yesterday night I had a conversation circling around that human ability to chase the understanding of the Universe, then arriving here and reading your words putting it in such a beautiful way…that was really nice.

  23. rvr

    SN1993j was discovered by Francisco García a Spaniard amateur astronomer member of Group M1. I remember that my local group received a call from the Group to help them confirming. Group M1 tell the discovery story here: http://astrosurf.com/blazar/articulo/i1993j.htm

  24. Meg

    “When those photons left that galaxy, there were no beings on Earth capable of understanding them. But during the intervening eons, our brains and eyes evolved, our imagination grew, and we became a species that can not only look up and wonder, but collect the feeble information that had previously fallen unheeded onto the ground and turn it into understanding.”

    This whole post was beautiful, but I especially loved this bit.

  25. I printed the 750 MB version on 13×19 (1200ish dpi woot!) photo paper as a poster for work. It rocks.

  26. I had a similar thought about 10 years ago when watching a TV special on astronomy hosted by Johnny Carson (yes, the talk show host, who was actually an avid amateur astronomer). He was talking about infrared astronomy and how most of the IR is absorbed by water in the atmosphere. I suddenly had this sudden feeling of loss when thinking that those photons had been travelling towards us for tens of millions of years, only to be stopped in the last few microseconds before reaching our eyes by this vanishingly thin layer of atmosphere.

    – Jack

  27. That’s it. I’m moving to somewhere really dark in the middle of Kansas and buying a big telescope. Now if I can only figure out how to finance this little mid-life crisis.
    Great post.

  28. (Off Topic Post)

    Phil –

    I know you’re busy unpacking and all, but when you get a chance, could you see if my address has somehow been blacklisted on the blog when coming from a Windows system? That post I just made is the first one that’s gone through in over two weeks. I did that one (and this one) from my Linux system using Firefox.Every other attempt has simply vanished into the ether. There’s no error message, the post just doesn’t show up. If I try to send it a second time, I get the “You already said that” message.


    – Jack

  29. Gilles: the matter is NOT spiraling into the black hole! The BH in the center is tiny compared ot the rest of the galaxy, and the stars, gas and dust will orbit around for trillions of years. More, maybe.

    Rowsdower: I was actually going to add a bit about the background galaxies, but decided not to since it took away from the point I was making. If you go to the links provided in the post, you’ll see some great images of more distant galaxies in the image. There’s a spiral sitting next to an edge-on spiral (or maybe an irregular, hard to tell) and it looks like a lollipop!

  30. How big is M81 in comparison to our own galaxy?

  31. Gilles

    The BA wrote : « the matter is not spiraling into the black hole ! »
    Thanks. I only said it looks like everything is dragged into a drain. I’ll describe my impression in another way : It looks like cream stirred in a coffee cup.

  32. WJM

    Again with that image, you zoom into the starfield “foreground”, and you end up looking at the galaxies in the background.

    I’ve been re-reading Goldsmith, The Astronomers, lately. Last summer’s reading included Overbye, Lonely Hearts of the Cosmos. Along with posts like this one from BA, I swing between being amazed by it all, or overwhelmed.

  33. Carolyn

    Electronics are very useful but…it’s great to get away from them sometimes. My recent experience isn’t with astronomy, but with classical concerts. No microphones, amplifiers etc. Some of the musical instruments dated back to the seventeenth century. I know, it’s not millions of years…

    CloudFrog – maybe not so off-topic. There’s a link from the Kentucky Museum website to Answers in Genesis which has a pdf “What Does the Bible Say About Astronomy?” which says that spiral galaxies cannot be more than a few thousand years old, because if they were they would have lost their spiral structure due to the arms being too tightly wound up.

  34. CR

    Jack Hagerty— several weeks ago, I encountered the exact same problem with not being able to post. Lasted for a few weeks, in fact, but I was eventually able to post again. Don’t know what happened, though I’ve since noticed that I can no longer post anything containing a link.

    Carolyn— Not treally directed to you, but since you brought it up… Galaxies’ spiral arms being too tightly wound up would cause them to lose their spiral structure? What are they thinking? I mean, what in the world does that even MEAN? Are we supposed to go, “Oh, that’s right, then” and not realize such a thing makes less sense than an old universe?

  35. i just want to know how the feeling i will be if i were there

  36. Carolyn

    “What Does the Bible Say About Astronomy” by ‘Dr. Jason Lisle, Ph.D in astrophysics’ is here: http://www.answersingenesis.org/radio/pdf/astronomy.pdf

    [Last time I tried to do links here I got the syntax wrong and my whole comment ended up as a link and I can’t edit it!]

    It says the spiral structure would become unrecognisable because the inner regions rotate faster than the outer so the spiral becomes tighter.

    The same article claims that at the speed the Moon is receding it would have been touching the Earth 1.4 billion years ago.

    I can’t do the maths for this, perhaps I should ask on the baut forum!

  37. Carolyn:

    It says the spiral structure would become unrecognisable because the inner regions rotate faster than the outer so the spiral becomes tighter.

    The same article claims that at the speed the Moon is receding it would have been touching the Earth 1.4 billion years ago.

    As is usual for creationists, they pose a problem without bothering to look for the resolution, which in both cases has been known for a long time (and is usually in the top few search results on Google).

    The second “problem” is easily dealt with: the Moon’s recession speed isn’t constant. Even if it were, a ~1.4 billion-year old Moon is just as much a problem for “young Earth creationists” as a ~4 billion year old one.

    Spiral arms are a little tougher, because the explanation isn’t widely known outside the astronomical community. Our current understanding is that the arms are density waves, regions of enhanced star formation that don’t revolve at the same speed as the stars and star-forming gas themselves. Since these are star-forming regions, we see lots of bright new stars in the arms — but existing stars actually pass through the waves, meaning that over time, the arms consist of entirely different stars. There are several variants on this basic idea, but the end result is the same: the arms’ dynamics are different from the stellar dynamics, and there’s no contradiction. Wikipedia has a good summary (under “spiral galaxy”), and there are plenty of links elsewhere.

  38. Sergeant Zim

    Cloud Frog, in reply to your plan to take a pad and pencil to the Creation Museum to record all the scientific errors/misconceptions/outright lies therein;

    To paraphrase Sheriff Brody (from the movie, “Jaws”) “You’re gonna need a bigger book”

  39. CloudFrog

    Okay, I just got back again. I have about 70 photos to upload, which I will get to tomorrow some time. It turns out that I missed more than HALF of the museum tour the first day because we went through a wrong door in fear of missing the Planetarium exhibit.

    One thing that really did frustrate me quite a bit while I was there today was that I ran into several teachers that actually taught me in high school. Two of them were science teachers at that, which makes me fearful that maybe they’re implanting this garbage into the local youth. There was also a prayer circle outside praying for the souls of darwinists, skeptics and people who believe in the concept of evolution.

    On the other hand, I ran into far more people today than on opening day who were obvious skeptics. One T-shirt inparticular: “Creationism is Hilarious!”

  40. Carolyn

    ColoRambler – thanks for the info about the dynamics of spiral galaxies. I’ll look up the Wikipedia article.

    One final comment about the creationist museum from an article I read in New Humanist magazine. Do they really claim T. Rex had sharp teeth so it could eat coconuts?!?

  41. The second “problem” is easily dealt with: the Moon’s recession speed isn’t constant. Even if it were, a ~1.4 billion-year old Moon is just as much a problem for “young Earth creationists” as a ~4 billion year old one.

    It’s even worse than that. Even though we know (ask Google, if you must) that the recession speed isn’t constant, let’s assume it is. If you use Mr. Lisle’s figure of “the moon moves about an inch and a half away from the earth every year”, then after 1.4 billion years you have:

    1.4×10^9 years * 1.5 inches/year = 2.1×10^9 inches
    = 1.75×10^8 feet (divide by 12)
    = 33,140 miles (divide by 5280)

    Oops. That’s only about 13% the Moon’s current distance. The Moon wouldn’t have been touching the Earth 1.4 billion years ago; it wasn’t anywhere close, even with a constant recession speed. An extra 3 billion years or so wouldn’t be a problem.

    Depending on the accuracy of his “about an inch and a half” — in particular, if it’s more like an inch and a quarter — he might have gotten 1.4 billion by dropping a zero in his calculation, with an actual result of 14 billion years. This is something physics students the world around can surely relate to. Given this is a creationist, however, I wouldn’t hold my breath waiting for a retraction.

  42. Buzz Parsec

    ColoR –

    I *believe* :-) you’re getting the result because you are failing to use Intelligent Math (IM) for your calculation. In order to correctly use IM, you need to start with your conclusion (the Moon is 6000 years old), and then derive your arithmetic from that fact.

  43. Buzz Parsec

    Whoops! I saw that typo but forgot to correct it before hitting SUBMIT.

    > I *believe* you’re getting the *WRONG* result…

  44. When my six-year-old daughter asked what my new wallpaper was I told her it was the Galaxy M81.

    She said “Why is it mad?”

    I said had “M eighty one”
    She heard “M-A-D 1”

    We got it sorted out. 😀

  45. It’s mad because the line for Starbucks is so long out there so it hasn’t had it’s coffee yet.

  46. Sergeant Zim

    ColoRambler, I did the same thing you did, and came up with the following:

    4.5 X 10^9 years* 1.5 inches per year = 6.75 * 10^9 inches
    5.625 X 10^8 feet
    106,000 miles in 4.5 billion years.
    240,000 miles (approximate current distance) ~ 106,000 miles (4.5 billion years of recession) = ~134,000 miles (original distance)


    Wikipedia gives the Roche Limit for Earth/Moon as 9496 km/5900 miles (assuming the Moon is a rigid body).

    This is, of course, taking the current recession rate as accurate, and unchanging, and allowing for some rounding errors.

    If I’ve miscalculated, please let me know.

  47. Sergeant Zim

    BTW, in that same article in Wikipedia, there is a link to another article about extreme tidal distortion. That case is when an astronaut (or other object) gets too close to a Neutron star or a Black Hole, and becomes stretched like a piece of spaghetti.


    All praise His noodly appendage!

  48. If I’ve miscalculated, please let me know.

    You haven’t — I was just trying to see if the “1.4 billion year” timeframe made any sense, so I didn’t bother working things out at other times. Over 4.5 billion years, your answer looks right.

    Of course, we both assume a constant recession speed. Not only is it variable (in a manner that’s difficult to predict without some fairly heavy-duty math), it’s actually been lower in the past (http://www.talkorigins.org/faqs/moonrec.html). We have measurements based on geologic evidence going back over 2 billion years, so it’s safe to say there’s no realistic physical model that predicts lunar contact 1.4 billion years ago.

    Mind you, creationists sometimes do find some goofy equation or other to work with (look up “c-decay” on Google for some fun ones), so I suppose this fellow could have found some plausible but wrong way to come up with 240,000 miles in 1.4 billion years. He never actually says how he got his numbers, so I have no way to comment.

  49. MattFunke

    CloudFrog: “Finally, the guy made the point that because of the gravitational pull that large objects in space have on light, it’s possible for us to observe objects that far away even though they are only 6,000 years old because of some temporal fiction they came up with.”

    I know you know this, but it’s worth mentioning. Even if light were “pulled” by gravity along the way, that would only change the *frequency* of the light, not its *velocity*.

    A lot of YECist arguments, it appears, rely on using arguments that sound plausible, but don’t actually work in the Universe we inhabit.


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