Heard at the live AAS press conference (in progress here, availability announced here):

At Spitzer/Caltech: Two of the Milky Way's Spiral Arms Go Missing see the latest portrait of our galaxy.



Bigger Pictures (one annotated with sun's location and our vantage point's major visible features)

Yesteryear's version:

Milky-Way-Drawing.jpg

Edit: 17 past the hour. Press conference over.

Edit: Additional source for same stuff: NASA Spitzer Mission :: Multimedia: Our Milky Way Gets a Makeover

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Uh-oh.

EVERYBODY PANIC! The Milky Way Galaxy is disappearing! First, we lost half of the Galaxy's mass. Now, we're losing entire spiral arms!! By the end of 2012, our Galaxy will be gone! The Mayans knew it all along!

Sorry, I went into woo-woo mode for a second there. Actually, it's pretty interesting to think we're living in a barred spiral galaxy.

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Yes, they laughed at Einstein, but only because of his silly hairstyle; no one was actually laughing at his science.

I knew those Masons were up to something...

And someone in the chat room asked about how MW fits in and one presenter declared us a pretty normal barred spiral galaxy. Whew.

(I just think it's so cool to be able to ask such questions at an astronomy-discovery press conference.)

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Don't worry, galaxies, like starfish, can grow their arms back.

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009

They didn't disappear. They just got downgraded to minor arms. At least Pluto won't feel lonely any more.

Does Orion's Arm (Wikipedia) have to change its name to Orion's Spur?

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I believe the new name will be "The Orion Suburb."

Does that mean that the Milky Way can now be reclassified as "Mostly Armless?"

(yeah, I just used the same line over on the UT site, but why waste a good good one-liner, I say!)

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

The Andromadeans will think we are easy prey. After all, we are unarmed.

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Fields of Space

LOGIC, n.
The art of thinking and reasoning in strict accordance with the limitations and incapacities of the human misunderstanding.

In the Year 2525.

"One small step for (a) man. One giant leap for mankind".

If an astronaut doesn't need good grammar, niether does you.

Host of Seraphim

I think our galaxy looks nicer now. Much more elegant and feminine.

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Wikipedia: A MMORPG for self-denialists.

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

Losing a trillion solar masses would do wonders for anyone's figure.

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"Illuminati's Razor - The most complicatedly evil answer is usually the most correct answer."
-- Fazor

Orion's Spur? I think not.

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Orion's Arm . The Starlark . Voices: Future Tense- Novella Contest Issue! . OA Flickr set

That's funny (odd funny, not 'haha' funny). I've been using the Orion Spur as part of my address for a number of years now...

Latitude: 34° xx' xx" N
Longitude: 117° xx' xx" W
Planet: Terra (Earth)
Star: Sol
Arm: Orion Spur
Galaxy: Milky Way
Verse: Uni

Note that this survey does not actually affect the significance of the Orion Arm, or Spur, directly; it is mainly concerned with the status of the Sagittarus and Norma Arms, which have both been relegated to minor arm status. The Orion Arm (or Spur) was already a minor arm, so its status is unchanged.

Discussions at Celestia so far have gone against changing the representation of the galaxy in that program yet, as the shapes of the spiral arms in the model are based on the COBE and 2MASS surveys, which don't seem to suggest that the Sagittarius and Norma arms should, in fact, be relegated. Yet.

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Orion's Arm . The Starlark . Voices: Future Tense- Novella Contest Issue! . OA Flickr set

You just wait. Soon people will be clamoring about their demotion, claiming that the vote wasn't representative, and that they will still refer to them as fully fledged arms regardless of what any pompous astronomers think.

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Wikipedia: A MMORPG for self-denialists.

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

First Pluto is demoted, then the galaxy. Next thing we know, the entire universe will be relegated to some locker in a train station.

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jwj

It's ok not to know. We should try harder to find out.

I wish you were right but I think we're barred!

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* Never doubt there is Truth; just doubt that you have it!

I don't know if the Spitzer site has it, but APOD published an annotated version of the image:

http://antwrp.gsfc.nasa.gov/apod/ap080606.html

It seems that one of the minor arms - the 'Outer Arm' - is the longest, although it's broken up in places. Very cool stuff.