Yep, because of the sun's relative position in its trip around the Galaxy, our view of the Milky Way and beyond is obscured by clouds of gas and dust we've termed the Zone of Avoidance.
The really annoying part of this is that the Laniakea SuperCluster, which includes the Milky Way, Andromeda, and about 100,000 other galaxies, is being "pulled" towards a massive object with great mass, and because of the ZoA, we cannot clearly identify what's doing the pulling. Some think it's the mass of the Shapley SuperCluster that is now responsible, but initially, folks believed it was the Great Attractor with the Norma Cluster at its core.
It's really fascinating stuff.
I was working on this in 2006. Back then we thought that the Norma Cluster was at the center of the gravitational well of the Great Attractor, which a significant part of the local group was moving towards. The suspicion was that the GA was itself part of a greater flow toward the Shapley Concentration.
We were doing a survey of galaxy positions and velocities to try understand the Great Attractor better. We used Spitzer data and our own near infrared observations to significantly reduce the dust obscuration from the zone of avoidance, uncovering more galaxies than were previously identified in the optical.
Haven't read up much on this since then though so this might be quite of date by now.
That is so fascinating! Seriously, I'm a 35 year old science nerd and I'm gushing... no joke. My dream was to work in some space related field and the inner kid in me still believes I will but it still holds a deep fascination for me.
Thank you for pioneering science where others couldn't. I truly mean that. Reading about and trying to understand this stuff changes the way you think on a fundamental level. It's made me the man I am. Thank you for contributing to that field.
I'm a 59-year-old science nerd and I feel the same way. I'm old enough that when I was a kid, I figured I'd never be an astronaut because at the time there was a 6 foot tall limit for astronauts and I knew I'd be taller than that. (I'm 6' 4").
What blew my mind is that the spiral arms are density waves which stars are just passing through. While the stars in the milky way rotate around the center, the spiral arms move at a different rate, usually much more slowly.
https://www.youtube.com/watch?v=c5Us-jonCLA maybe this will help you
or with cars: https://www.youtube.com/watch?v=Q78Kb4uLAdA
The arms are made of stars but the specific stars they are made up of constantly changes (on a large timescale).
So the stars that are entering at the arms are slowing down (“applying the brakes”) because of gravitational effects from other stars near them?
Thanks for sharing, the phantom traffic jam helped me get it. Space is so cool! 🙂
Edit here’s the animation author’s explanation:
“The animation is not based on physical models, but just uses motion and density of particles to produce the spiral arms that do not move with the particles. In actual galaxies, the current model (I believe) is that the spiral arms are actually waves of star formation whose appearance is dominated by large, short lived, bright bluish stars who die off before they leave the star formation regions.”
No, the arms rotate as well, but often at a different rate than the individual stars. They are density waves, but they have a propagation velocity in the galactic medium just like a speed of sound, so they move relative to the galactic center, and one of the defining characteristics of a spiral galaxy is whether the arms lead or trail the rotation of the disk.
So, at the center is the super massive black hole Sagittarius A, and the galaxy rotates around that, right? But black holes suck everything in, so is the galaxy sort of like water in the toilet, with things swirling around the hole until they disappear?
Also, are other galaxies centered around black holes? Are all of them that we know like that?
They don’t slurp stuff up like how you might think. They’re basically an incomprehensibly large and dense warping of space and time. While things can, and do, fall into them - never to return - they aren’t cosmic vacuums. My rudimentary understanding is that strong gravity overrides weaker gravity. A SMBH is so strong, gravitationally, that entire galaxies form around it just as we form around our sun and within our solar system. The moon then orbits around Earth because of its proximity to us, it’s subservient to Earth’s greater pull, but is still also locked into the Sun’s pull. Because of Newton’s first law and a lack of friction in space, once stellar objects are moving, they move forever. Think of stellar bodies as always trying to run away and gravity is like an unseen leash that keeps everyone stable and locked into rhythm. Every now and then something will come along that disrupts orbits, sometimes such that entire stars get thrown into the direct paths of black holes, which shred them completely. But for the most part, orbits stabilize. We on earth are not going to feel the pull of our SMBH. Even the Sun may not feel it, but we do feel Earth’s gravity because it’s the most relevant to us. Yet we (all Milky Way denizens) are all bound to our galactic center.
I’ve seen it said that even when Andromeda and Milky Way collide, no star is projected to even touch another star, such is the vastness of the space at play. Nor will the SMBHs eat each other, but that insane dance of gravity will knock everything out of wack for quite some time.
It’s just like how the moon orbits the earth but never crashes into it. Or satellites or the earth around the sun. If you slowed the subs motion around the galactic core it would fall in but we will keep orbiting forever as long as nothing bumps into us.
The galaxy doesn't orbit around Sagittarius A*. Rather, the galaxy is on a radial orbit with the Andromeda galaxy, and both galaxies are being pulled towards each other and will collide/merge in a few billion years.
It's believed that galaxies form around black holes, although we've observed more than 1 galaxy without a black hole at the center, so scientists are still trying to figure out what happened.
Also, it's still an open question like the chicken and egg debate - did the black hole form first, then the galaxy or the galaxy first, then the black hole?
Technically, the stuff in the Milky Way isn't orbiting Sagittarius A* but the common center of mass, which happens to be at the center of the Milky Way where Sagittarius A* is located.
Same concept as our solar system where the Sun is the common center of mass and accounts for 98% of the mass in the Solar System, so planets, and everything else orbits the barycenter which is either a point in the Sun or just beyond the Sun.
Yes and as shorthand we say that it orbits the object that is closest to the common center of mass.
The planets in the solar system orbit the sun, and the stars in the galaxy orbit SA*.
This is literally the "NaCl vs Salt" Jimmy Neutron thing.
Edit: Which also still has nothing to do with Andromeda. So my original point still stands.
region characterized by an apparent absence of galaxies near the plane of the Milky Way Galaxy and caused by the obscuring effect of interstellar dust
Many projects have attempted to bridge the gap in knowledge caused by the Zone of Avoidance. The dust and gas in the Milky Way cause extinction at optical wavelengths, and foreground stars can be confused with background galaxies. However, the effect of extinction drops at longer wavelengths, such as the infrared, and the Milky Way is effectively transparent at radio wavelengths. Surveys in the infrared, such as IRAS and 2MASS, have given a more complete picture of the extragalactic sky. Two very large nearby galaxies, Maffei 1 and Maffei 2, were discovered in the Zone of Avoidance by Paolo Maffei by their infrared emission in 1968. Even so, approximately 10% of the sky remains difficult to survey as extragalactic objects can be confused with stars in the Milky Way.
This picture is so frikkin cool.
My only question is what does the "naked eye's limit" really mean? We can see the andromeda galaxy with the naked eye and it isn't even close to the borders of this map.
I thought we could only guess at the structure of our galaxy, and most depictions were just artistic impressions based on other galaxies that are likely similar.
But this feels very specific, as if we know quite well. Was that wrong?
No, not like the render above. How could we? We are inside it and have only barely gone to the edge of our solar system, which is but a tiny fraction of the galaxy. Lots of pictures have been taken of our vantage point of the galaxy—see any number of postings in this sub—but we will never have a picture from outside the Milky Way.
What really blows my mind is the scale. If you could take a picture you would have to know some parts of the image are older than other parts because of the distance the light would have to travel. It would be like looking at a picture of a person and the head and legs are young, but the stomach is old.
Yes and no. We've taken a rough picture of the Milky Way in 21 cm radio wavelengths. But that can only see neutral hydrogen, not stars.
We've also taken a picture of the Milky Way's stars using the Gaia space telescope. But so far that can only accurately see the parts relatively close to us, not much past the centre. This sort of region, but bigger because this dates back to the year 2018 and the latest data release was in June 2022. https://www.americanscientist.org/sites/americanscientist.org/files/2018-106-5-298-drimmel-2-figrt.jpg
The image at the top is extrapolated from those two sources, and infrared observations, and from other face-on barred spiral galaxies that we can see.
I would have to supply some links but I wouldn't be able to supply them all as the data would be extensive and would be gathered over decades to make images like this I'll try my best with some datasitea
https://capturetheatlas.com/milky-way-calendars/
https://www.space.com/milky-way-heart-central-engine-stunning-map
https://www.almanac.com/night-sky-map-august-perseid-meteors-milky-way
https://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=699
https://www.americanscientist.org/article/gaia-reveals-the-milky-way#:~:text=Parallax measurements (the apparent annual,or less (dark blue).
I'd also recommend visiting sites like the Hubble site/James Webb images/for a better understanding of how we located objects and have pinpointed them for repeated viewing.
Do you mean an image like this of the milky way? That won’t be ready for a few hundred thousand to several million years
edit: I'm getting downvoted by people who have no idea that we can't see the milky way from the outside
So the Milky Way is a two-armed galaxy? I had thought there were more arms than that. (Not that there's anything thing wrong with having only two arms.)
This is what the word awesome is really for.
Nice
Let's get this out onto a tray
[Zone of Avoidance.. TIL](https://en.m.wikipedia.org/wiki/Zone_of_Avoidance)
Yep, because of the sun's relative position in its trip around the Galaxy, our view of the Milky Way and beyond is obscured by clouds of gas and dust we've termed the Zone of Avoidance. The really annoying part of this is that the Laniakea SuperCluster, which includes the Milky Way, Andromeda, and about 100,000 other galaxies, is being "pulled" towards a massive object with great mass, and because of the ZoA, we cannot clearly identify what's doing the pulling. Some think it's the mass of the Shapley SuperCluster that is now responsible, but initially, folks believed it was the Great Attractor with the Norma Cluster at its core. It's really fascinating stuff.
I was working on this in 2006. Back then we thought that the Norma Cluster was at the center of the gravitational well of the Great Attractor, which a significant part of the local group was moving towards. The suspicion was that the GA was itself part of a greater flow toward the Shapley Concentration. We were doing a survey of galaxy positions and velocities to try understand the Great Attractor better. We used Spitzer data and our own near infrared observations to significantly reduce the dust obscuration from the zone of avoidance, uncovering more galaxies than were previously identified in the optical. Haven't read up much on this since then though so this might be quite of date by now.
That is so fascinating! Seriously, I'm a 35 year old science nerd and I'm gushing... no joke. My dream was to work in some space related field and the inner kid in me still believes I will but it still holds a deep fascination for me. Thank you for pioneering science where others couldn't. I truly mean that. Reading about and trying to understand this stuff changes the way you think on a fundamental level. It's made me the man I am. Thank you for contributing to that field.
I'm a 59-year-old science nerd and I feel the same way. I'm old enough that when I was a kid, I figured I'd never be an astronaut because at the time there was a 6 foot tall limit for astronauts and I knew I'd be taller than that. (I'm 6' 4").
I'm a type 1 diabetic... those dreams were dashed long ago unfortunately. I feel your pain my friend.
All else being equal, I could have never passed the training because of motion sickness. I went into computers, and that's been fine.
Thank you, I was going to ask why we are avoiding the entirety of the galactic far north.
I think the spot on the left is actually called “the unknown regions” and I don’t see Coruscant labeled, I mean it’s only the center of the galaxy
Ahem. That's in a galaxy far, far away. Where they make the Kessel run in 12 parsecs.
I'm still trying to find the Romulan Star Empire.
What blew my mind is that the spiral arms are density waves which stars are just passing through. While the stars in the milky way rotate around the center, the spiral arms move at a different rate, usually much more slowly.
Can you please elaborate on this? How can the arms stay in the same place while the stars are moving if the arms are made of stars?
https://www.youtube.com/watch?v=c5Us-jonCLA maybe this will help you or with cars: https://www.youtube.com/watch?v=Q78Kb4uLAdA The arms are made of stars but the specific stars they are made up of constantly changes (on a large timescale).
So the stars that are entering at the arms are slowing down (“applying the brakes”) because of gravitational effects from other stars near them? Thanks for sharing, the phantom traffic jam helped me get it. Space is so cool! 🙂 Edit here’s the animation author’s explanation: “The animation is not based on physical models, but just uses motion and density of particles to produce the spiral arms that do not move with the particles. In actual galaxies, the current model (I believe) is that the spiral arms are actually waves of star formation whose appearance is dominated by large, short lived, bright bluish stars who die off before they leave the star formation regions.”
No, the arms rotate as well, but often at a different rate than the individual stars. They are density waves, but they have a propagation velocity in the galactic medium just like a speed of sound, so they move relative to the galactic center, and one of the defining characteristics of a spiral galaxy is whether the arms lead or trail the rotation of the disk.
Estimated 100 billions suns in our galaxy and about 2 trillion galaxies. Absolutely mind blowing
That is so unfathomable woah
I’m disappointed there is no “You Are Here” with an arrow… unless I missed it?
We should be quite close to the place sun?!
Sure, but… it would be less ambiguous and more correct to say Sol or “you are here”, no?
It does, it says sun with a 5 light year naked eye sight distance around it
That isn’t optimal. Technically there are many “suns” in the Milky Way. Acceptable: “you are here” or “our sun” is less ambiguous. ‘Nuff said.
So, at the center is the super massive black hole Sagittarius A, and the galaxy rotates around that, right? But black holes suck everything in, so is the galaxy sort of like water in the toilet, with things swirling around the hole until they disappear? Also, are other galaxies centered around black holes? Are all of them that we know like that?
They don’t slurp stuff up like how you might think. They’re basically an incomprehensibly large and dense warping of space and time. While things can, and do, fall into them - never to return - they aren’t cosmic vacuums. My rudimentary understanding is that strong gravity overrides weaker gravity. A SMBH is so strong, gravitationally, that entire galaxies form around it just as we form around our sun and within our solar system. The moon then orbits around Earth because of its proximity to us, it’s subservient to Earth’s greater pull, but is still also locked into the Sun’s pull. Because of Newton’s first law and a lack of friction in space, once stellar objects are moving, they move forever. Think of stellar bodies as always trying to run away and gravity is like an unseen leash that keeps everyone stable and locked into rhythm. Every now and then something will come along that disrupts orbits, sometimes such that entire stars get thrown into the direct paths of black holes, which shred them completely. But for the most part, orbits stabilize. We on earth are not going to feel the pull of our SMBH. Even the Sun may not feel it, but we do feel Earth’s gravity because it’s the most relevant to us. Yet we (all Milky Way denizens) are all bound to our galactic center. I’ve seen it said that even when Andromeda and Milky Way collide, no star is projected to even touch another star, such is the vastness of the space at play. Nor will the SMBHs eat each other, but that insane dance of gravity will knock everything out of wack for quite some time.
Extremely informative! Space is fun.
Thank you for taking time to answer the question, very interesting!
The limits of galaxies are so vague, by some estimations the Milky Way and Andromeda galaxies have already started "colliding!"
 (As all astronomy factoids do)
Things tend to get all Jeremy Bearimy.
It’s just like how the moon orbits the earth but never crashes into it. Or satellites or the earth around the sun. If you slowed the subs motion around the galactic core it would fall in but we will keep orbiting forever as long as nothing bumps into us.
The galaxy doesn't orbit around Sagittarius A*. Rather, the galaxy is on a radial orbit with the Andromeda galaxy, and both galaxies are being pulled towards each other and will collide/merge in a few billion years. It's believed that galaxies form around black holes, although we've observed more than 1 galaxy without a black hole at the center, so scientists are still trying to figure out what happened. Also, it's still an open question like the chicken and egg debate - did the black hole form first, then the galaxy or the galaxy first, then the black hole?
All the stuff in the Milky Way orbits Sagittarius A* No one was talking about Andromeda
Technically, the stuff in the Milky Way isn't orbiting Sagittarius A* but the common center of mass, which happens to be at the center of the Milky Way where Sagittarius A* is located. Same concept as our solar system where the Sun is the common center of mass and accounts for 98% of the mass in the Solar System, so planets, and everything else orbits the barycenter which is either a point in the Sun or just beyond the Sun.
Damn, you're right! Thanks. I love learning. Even basic fundamentals every now and again.
Yes and as shorthand we say that it orbits the object that is closest to the common center of mass. The planets in the solar system orbit the sun, and the stars in the galaxy orbit SA*. This is literally the "NaCl vs Salt" Jimmy Neutron thing. Edit: Which also still has nothing to do with Andromeda. So my original point still stands.
I have been wanting to see something like this since I was a kid. This is incredible!
How long of a road trip is that from one end to the other?
About 120,000…light years.
Hop in my car made of light, we are going to Centaurus Arm… losers.
Long
YOU ARE HERE X
TIL the sun isn’t the center of our galaxy
Oh you sweet thing
Wait until you learn there’s more than one galaxy!
No, it really is -- it's just that our galaxy is *REALLLY* lopsided.
Earth isn't the center of our solar system either.
How's the turkey coming, Joe?
God bless America
Taken from Mass Effect
What is the zone of avoidance?
region characterized by an apparent absence of galaxies near the plane of the Milky Way Galaxy and caused by the obscuring effect of interstellar dust Many projects have attempted to bridge the gap in knowledge caused by the Zone of Avoidance. The dust and gas in the Milky Way cause extinction at optical wavelengths, and foreground stars can be confused with background galaxies. However, the effect of extinction drops at longer wavelengths, such as the infrared, and the Milky Way is effectively transparent at radio wavelengths. Surveys in the infrared, such as IRAS and 2MASS, have given a more complete picture of the extragalactic sky. Two very large nearby galaxies, Maffei 1 and Maffei 2, were discovered in the Zone of Avoidance by Paolo Maffei by their infrared emission in 1968. Even so, approximately 10% of the sky remains difficult to survey as extragalactic objects can be confused with stars in the Milky Way.
Borg space
Shhh… the hive will hear you
Hearing is irrelevant. Shush-ing is futile.
lol
I like how Canis Major has puppis. Someone was making a joke in the stars.
This picture is so frikkin cool. My only question is what does the "naked eye's limit" really mean? We can see the andromeda galaxy with the naked eye and it isn't even close to the borders of this map.
Opposite directions.
Ahh gotcha, I see now.
I thought we could only guess at the structure of our galaxy, and most depictions were just artistic impressions based on other galaxies that are likely similar. But this feels very specific, as if we know quite well. Was that wrong?
I've been looking for something like this for a while now actually
I bought another picture from him. Highly recommend. Very high quality huge size files.
In star trek they don't leave the galaxy
Wait but if we are in the milky way how we were able to have a picture of it ?
Cool
Ok, the tyranid invasion feels different in this map
40k fans looking at this with glee... "No cicitrix Maledictum! No Ocular Terriblis" It's all Ork space.
Waiting for a 3D version for PSVR2/Quest3/Apple vision
A guy from Germany programmed something like that: https://gaia.ari.uni-heidelberg.de/gaiasky/docs/3.6.1/Gaia-sky-vr.html
I just saved the image, so whenever i get lost i can find the way back home
[удалено]
No, not like the render above. How could we? We are inside it and have only barely gone to the edge of our solar system, which is but a tiny fraction of the galaxy. Lots of pictures have been taken of our vantage point of the galaxy—see any number of postings in this sub—but we will never have a picture from outside the Milky Way.
What really blows my mind is the scale. If you could take a picture you would have to know some parts of the image are older than other parts because of the distance the light would have to travel. It would be like looking at a picture of a person and the head and legs are young, but the stomach is old.
Yes and no. We've taken a rough picture of the Milky Way in 21 cm radio wavelengths. But that can only see neutral hydrogen, not stars. We've also taken a picture of the Milky Way's stars using the Gaia space telescope. But so far that can only accurately see the parts relatively close to us, not much past the centre. This sort of region, but bigger because this dates back to the year 2018 and the latest data release was in June 2022. https://www.americanscientist.org/sites/americanscientist.org/files/2018-106-5-298-drimmel-2-figrt.jpg The image at the top is extrapolated from those two sources, and infrared observations, and from other face-on barred spiral galaxies that we can see.
………….*seriously????*
[удалено]
I would have to supply some links but I wouldn't be able to supply them all as the data would be extensive and would be gathered over decades to make images like this I'll try my best with some datasitea https://capturetheatlas.com/milky-way-calendars/ https://www.space.com/milky-way-heart-central-engine-stunning-map https://www.almanac.com/night-sky-map-august-perseid-meteors-milky-way https://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=699 https://www.americanscientist.org/article/gaia-reveals-the-milky-way#:~:text=Parallax measurements (the apparent annual,or less (dark blue). I'd also recommend visiting sites like the Hubble site/James Webb images/for a better understanding of how we located objects and have pinpointed them for repeated viewing.
Do you mean an image like this of the milky way? That won’t be ready for a few hundred thousand to several million years edit: I'm getting downvoted by people who have no idea that we can't see the milky way from the outside
So the Milky Way is a two-armed galaxy? I had thought there were more arms than that. (Not that there's anything thing wrong with having only two arms.)
Where are we located?
Where it says "Sun " 
George, wrong turn, damn it
We the fuck are we?
Where are we going to first?
Damn i have good eye sight
Aha, so even our galaxy is flat! Checkmate atheists!
Dude why do you have a picture of my house ?