The Event Horizon Telescope (EHT) has released the first image of our supermassive black hole, Sagittarius A*, in polarized light
Pro/ProcessedDamn this is cool! Thank you for the share!!!
7 billion times, the mass of our sun! 😳
That’s literally too big to wrap my mind around.
They get bigger, check out hypermassive black holes, and those things get stupid. Scale and human rationale break at that scale
Ton 618 and Phoenix A are staggering in scale. They make Sgr A* look like a random pebble. Both have event horizons bigger than our solar system. Phoenix is something like 100 billion solar masses. Ton is 'only' 33 billion. Just beyond comprehension. It's possible there are even larger ones out there too. The universe is just amazing!
In here because someone mentioned my boi, Ton 618. Ain't nobody do it thiccer 😤
Agree, and this is just what we can “see.”
Who knows what’s out there ever further…
Hey if mass isn't your thing and you want something with volume the you can look at and understand then you have 'UY Scuti', it's a slightly bigger sun then ours ... well bigger as in 5 billion of our sun's could fit Inside it.
That’s fucking mind-boggling. I had no idea stars could get that big.
That must be just shy of collapsing into a black hole, no?
Not really, it's biggest in volume but is 'empty' as far a mass goes and my very limited understanding is mass is important for black hole development.
If/when this collapses it's more likely to become a type of dwarf star
Thanks for the reply. Space is fascinating, that’s a fact.
To give some perspective (that, to be fair, is also at an unfathomable scale), if UY Scuti were to replace our sun, the only two planets that wouldn't be engulfed would be Uranus and Neptune, and only just barely for the former.
Wow…
I don’t understand how everybody on earth, isn’t fascinated with this stuff.
Every time I read about space, and the universe, my mind blows a fuse.
If everyone on earth loved science as much as we do I could see the possibility of ending all conflicts. Imagine all of humanity working towards a unified goal. We could get much more advanced in a shorter period of time. Imagine how fast we could become a Type 2 civilization let alone the theoretical Type 7. Instead we have greed, wrath, and envy leading our nations. It’s a damn shame
I hear you… Give it time my friend.
Hopefully it happens.
It’s probably just gonna take a long time, too, shed our ancestral negative tendencies… Hopefully in the future, things like greed, envy, spite, violence, etc., etc., will just be vestigial emotions, that we have shed…
Unfortunately, it ain’t gonna be in our lifetime brother.
Oh well, let’s have fun while we’re here, and try to be good people. ❤️💕✌️😊
Amazing video!
Have you ever seen that website, that starts from the scale of a virus, and scales up to the size of a black hole?
I forget what it’s called, (size of the universe maybe?) but I will try to find it for you.
It’s fucking amazing.
Edit: That guys YouTube channel is top-notch. Subscribed. Thanks for the link brother. ✌️💕
If you get close enough it'll wrap your head around it no problem
Nice… 👍
Spaghettification, does not sound fun. 😳
Thanks for sharing. Your posts and comments are always so informative. This one has given me yet another existential crisis about how big the universe is. The video of stars orbiting Sgr A* in particular left me slack jawed.
Anytime I feel overwhelmed by life and the world, I step outside and look up.
I either see the sun, a giant radioactive fireball that's so massive that stuff out to over 3 billion miles are impacted by it's gravity and is the only reason we as a species can survive on this rock we call home.
Or I see the stars of the night sky, some bigger and brighter than our sun by absurd amounts, that are so obscenely far away that the light I'm seeing predate written human history.
And I realize how tiny all of humanity is. How, no matter how much we hype ourselves up, we are but specks on another speck orbiting another speck. Helps me put things in perspective.
Carl Sagan really put it best with the Pale Blue Dot image
I know, right? I wonder how much that video was sped up?
If at all…
The orbital period of that fast moving star (s0-2) around Sgr A* is ~16 earth years.
Thank you so much for writing this and for your work!
That video of the star orbiting the black hole is mind-blowing.
It's a time-lapse of I think 23 years, or thereabouts. It's one of my favorite things on the web
Your posts and comments are the only thing on Reddit longer than two sentences that I’ll read. And I do, every time I catch one.
Thank you for not only sharing but explaining it so well and in such detail!
It's so unreal, I'm having trouble accepting that this image is not computer-generated/CGI/photshopped. Zooming in on the image, the strands of light seem pixelated - is it because it's a low-resolution?
One last comment on this and I'll stop being a negative Nancy, but you're right: these lines and their width are an overlay with line density chosen by the authors. The line width does not represent the image resolution. See the figure caption for fig 10 in the original paper. I quoted it in another comment, don't have it handy here. Still very cool and representative of real polarization data, but easy to over-interpret.
It's literally such high resolution that you would be able to see an orange on the moon.
But yes, literally any telescope at some point is going to have a resolution limitation.
An orange on the moon! Love it. This is why I love this video by Epic Spaceman, when he reduces the solar system to the size of NYC..."we're on a grape, trying to look at a melon (Neptune), in the dark, 11 kilometers away".
Fun fact for anyone reading -- The moon is so far away, all of the planets (Mercury through Neptune) can fit in between Earth and the moon. And we can see a orange on it!
thank you for linking this youtube channel, this vid earned him an instant sub for me and I strongly recommend this to anyone even mildy interested in astrophysics or even just science in general <3
The rough math I have in the back of my head is: The moon is 30 earths away from us. The sun is 100 times wider and a million times larger than the earth. The sun is 10,000 earths (~100 suns) away from us. The earth covers a distance of ~200 earths in its orbit every day!
What’s the scale of this picture in relation to how big the black hole is and how far out does the picture extend?
absolute humongous accomplishment. big ups :)
very VERY cool write up. Approachable in explanation and content. Thank you
Very nice writeup. I should probably read the paper, but if it's easy: what does the image actually represent? Are the streaks artifically added on top of the unpolarized image to indicate the direction of polarization for each region, with maybe the density of lines representing degree of polarization?
The image represents all the polarized light from this objects. It's literally what it looks like, not added on or anything like that.
I looked at the paper (32 pages..) and it is in fact an artificial overlay, not a direct image. See the Fig. 10 (bottom) caption:
"Polarization “field lines” plotted atop an underlying total-intensity image*. Treating the linear polarization as a vector field, the sweeping lines in the images represent streamlines of this field and thus trace the EVPA patterns in the image. To emphasize the regions with stronger polarization detections, we have scaled the length and opacity of these streamlines as the square of the polarized intensity.*"
So the measurement is great and their graphic representation striking, but it suggests higher angular resolution than the measurements actually have.
Thank you! The resolution looked suspicious to me. I wonder how they decide the separation distance of the lines in the polarization plot
Yeah not sure tbh, might partly be visual appeal. In any streamline plot you're free to choose overall line density (but changes in density should mean something). They say they scaled the length and opacity of the streamlines to match intensity. I'm confused by the length statement since all streamlines span almost half a full turn.
Thank you! Wish this was further up... like I understand polarization and stuff but did not get what that refers to. Talking about light polarization assumes a certain coordinate system, and without that assumption isn't it kind of meaningless ?
That's incredible, I'll have to read up on this. If those features are actually resolved, it looks like the polarization image has a well over ten times higher angular resolution than the 2017 unpolarized intensity image, but both were measured with the EHT (right?). Or perhaps the blurry look of the 2017 image was not in fact resolution limited? Either way, intriguing!
I thought your post suggested it's technically a colourised radio telescope image of the event horizon around the SMBH?
thanks so much for writing all these learnings and sharing your experience! awesome!
This is really fantastic data. I never thought I'd see this image in my lifetime due to all the complexities involved.
Why is it called Sagittarius A-star when it’s not a star? Shouldn’t it be Sagittarius A-hole?
It's a historical thing, where when the region was first observed in radio it was all Sagittarius A, then this was a blob off to the main emission so was designated as different with a *.
User deleted comment
2mo
Because it's not purple either, so we may as well do a color scale that is easily visible to people. (Purple also has issues in telling gradients for colorblind people, IIRC.)
I can tell you that I wouldn't be able to see purple well at all. (Purple light looks pinkish for the most part.)
Because purple is not very star coloured. Also this gives a hint as to the temperature of what we’re seeing. Red is coldest, blue/white is hottest
I recommend this episode of deGrasse's Startalk about coloring of space pictures https://youtu.be/RC4NUi-VwLY
Amazing write up!
I’m always so excited to see your comments on these posts! Thanks for the explanation!
Thanks for the write up!
This is the kind of post that makes reddit Great
You really are my favorite redditor!
Have you ever considered doing a YouTube channel or something? You explain things so well!
You're awesome
You do such excellent science communication on here. Thank you!
Keep being amazing, space research people!
Incredible write up, thank you so much for taking the time to share all of this.
NERD!
just kidding, this stuff is all so interesting to me and I really appreciate your breadth of knowledge and ability to dumb it down and share with us.
Hey, thanks for your comment.
Any chance we can get such a picture of TON 618, Phoenix A or any other of the SLABs? I mean these are yet another few dimensions of size larger than M87*.
Thanks again for you contributions!
I thank you for being smart.
Why does the spiral look square-ish?
The lines are so big that they look straight. Honest guess.
The lines are straight, because light travels in a straight line.
It's the spacetime that's bent.
they're geodesic :D
i'd imagine the rotation "drag" effect is not THAT huge (that's a total guess and my GR intuition is trash lol)
hey just like that storm on jupiter... or was it saturn.
I kind of wonder if this same phenomenon has any relation to the hexagonal formations at Jupiter / Saturn poles?
I swear, looking at the picture - a hexagonal formation would explain some of the "straightness" in lines - almost as if the speed at which light travels is being accelerated and decelerated near the black hole due to its effect on space time.
I remember reading something about a hexagon being the most "stable" shape, hence it's prevalence in nature when other such defined shapes are less common. I'm a dummy, but I'm sure someone will come along with the maths to clarify or completely dispute this.
probably an artifact of it being a 3d object + how the electromagnetic signals were massaged into the data that makes up the image to begin with which is why the lines look distinct in the first place.
I'd think we're not straight on or perpendicular to the hole, so a slight tilt like the rings of a planet could cause the near and far sides to curve a bit, but the space between them looks straight, because it's being bent less or something.
Spacetime being dragged along the electromagnetic field lines...so cool
Me reading your super long well thought comment understanding 8% of it but still getting excited.
The accretion disk here is magnetic signals right? Visualized?
Electromagnetic. We are collecting radio data for radio telescopes, and because the "twist" of the light relates to the magnetic fields present you can calculate quite a bit about the existing magnetic fields once you have the polarized radio data.
Thanks!
We live in the future. We can take pictures of black holes in this level of detail. Incredible.
More render than take. Cool nonetheless though!!
So these are rendered?
It's created from data collected by a radio telescope, so it's not visible light. The top comment is by an actual radio astronomer who I'm sure can explain better.
This is incredible, thank you for such an informative write-up. Is there at all a link to a high resolution version of this image?
There is a part of my brain that just can't comprehend that this could be a real image.. and I believe this shit. The "moon landing is fake" people are going to have a field day with some of the images that are going to be come out of EHT. So frikin cool man.
Well to be fair this isn't a "real image". It's created based on a series of measurements to show us what it would look like if we could see it.
I disagree, it's more than that. This is what it would look like if you had eyes that worked at 350 GHz and a pupil the size of Earth.
What I'm having trouble understanding is how clean and crisp those field lines are. Is that the actual radio image or is it part of post processing to clean it up and make it more resolute? It's an incredible image either way
It's their way of representing polarization. The density of those lines was chosen by the authors. The resolution of the image is way lower than those detailed lines make it seem (see their figure 10 caption).
Got it, thanks. Thats what i figured. I'm having trouble opening those links that OP provided on my cellphone.
This is the paper. Opens OK on my iphone. Figure 10 has the image we're looking at here. https://iopscience.iop.org/article/10.3847/2041-8213/ad2df0/pdf
Got it. Thank you much for the link.
Ooh, thank you for that link! The other pictures on that same page (pg. 12) give a great idea of what we're looking at and how this image was constructed.
All radio images have processing, so IDK what to tell you.
How different is tht from an image made (and displayed) by your phone camera?
The picture literally broke my brain. I could not believe that is was real. Absolutely awesome science, and thank you for sharing your knowledge and insight. It amazes me that just a century ago, we weren’t even sure if there were other galaxies beyond our own, and now we have pictures of space and time warping objects (or at least there effects on the surrounding environment). What a time to be alive!
Looks like a wormhole entrance that I've always envisioned. Neat.
I went to see Professor Brain Cox last night speaking about black holes and he said the photo he had and the research so far hes using will be different in a years time if we were to do the same show again. Not even 12hs and a new updated photo has been released... Truly amazing.
Won't you come
COOL
New wallpaper just dropped.
I'd like to jump in... Hopefully it will send me to a better plane of existence... If not, at least I will be out of this one...
What a glorious write-up! Superb, detailed information, and enlightening for those like me, hungry for the inside scoop on black holes. Thank you so much!
(No, I’m not a bot, but I sound like one. 😀)
How far out from the event horizon would time be warped like in the movie Interstellar?
infinitely far. Just that the effect goes down the farther away you go, inverse squared or something.
The earth warps time too and your head is like 0.0000001 seconds older than your feet when you die.
This is so good, thanks for sharing!!!
Are the striations actually taken from the image or has the image been enhanced in some form to show them? They make for a strange juxtaposition relative to the blurry light that shrouds them.
Ah, that's where all the 10mm sockets went
Incredible!!!
Neat
If you’ve seen one spinning black hole, you’ve seen them all.
Seriously though - I thought our view of SagA* was effectively blocked by the “stuff” you mentioned. Is this a direct image or a simulation?
Also - I’ve been trying to imagine what life would be like on a planet orbiting a star that itself orbits SagA. What would the night sky look like at the galactic center? Would the *be a night? How would conditions change as the star’s approached perigee around SagA*? And what would it mean to inhabitants of the planet if the star achieves relativistic speeds at perigee?
Please go read OP’s comment. It’s long, but it’s worth it and they actually go into your question a little bit.
WHAT A FANTASTIC POST!
Thank you! Well done!
My undergrad was in physics and I’m having difficulty understanding where the B-field is originating? From the center of the hole itself? Doesn’t that violate some laws, or do disturbances like E and B fields not get affected by strong gravity the same way? And if that’s the case, wouldn’t photons be able dip and out of the EH since their constituents are E and B fields? I am confused, proper
I’m so fucking stupid that when I saw those lines my immediate thought was “whoa it spins to the LEFT?!”
Ariel detergent
Why does the resolution of features in the yellow/white areas seem so much higher than the resolution of the darker areas, such as the perimeter of the black hole's shadow?
It almost looks like these are two images superimposed on each other, one blurry and one crisp. Are there two different types of measurements being combined into one visualization?
What a time to be alive! I’m really glad I have got to live this long. Black holes were basically the matter of fairytales when I was a kid.
Looks like my blender
I need this to be my new corporate logo.
Looks like a Cocteau Twins album cover. 👍
God. It’s so amazingly terrifying.
No that's the new Logitech logo
Event Horizon was a pretty damn good movie
I’m just imagining Mario getting sucked in and going “WOOOOOAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHH” while the black hole is like “NEEEEEEEERRRRRRRRRRRRROOOOOOOOOOOOOOOOONNNNNEEEEEEEEEE”
so black holes are galactic drains? cuz I see the same image everytime I drain the tub.
I'm so glad I live in times where I can see a picture of a blackhole, it's crazy.
I’ll show you a black hole..
“As far as I'm concerned, there's only one black hole worth studying.
It's called Sagittarius A. It's located in the center of our galaxy and it has the density of 40 suns.
Just like my wiener.”
-Pierce Hawthorne
Sure are a lot of weirdly negative comments here. I know this is Reddit but sometimes it still surprises me.
She’s a super mass, super mass - she’s super massive!
It would be a Sagittarius.
Great place to hide my browser history
(ie, it took light, the fastest thing there is, 27,000 light years to get here
I'm just here to be pedantic and point out that it took light 27,000 years to get here. "Light years" is distance, not time.
I know OP knows this, but I'm pointing it out to avoid laymen from repeating the mistake.
I feel so small.
Imagine if we had found a pupil inside of it. Anyway, this is mesmerizing
We are all just circling the drain.
This might be the best picture of my username
So how real is this? No way the arrangement has resolution to see those lines. This confuses most people and is not really helpful.
We're fortunate that this emits enough information to capture and amazing to think that we have instruments sensitive enough to collect it.
Thanks for the share, i always love to see something like this
Amazing. What is the location of this from perspective of humans looking into the sky?
It depends on your location, but Sag A* would be in the center of the Milky Way Band, the long streak of stars and dust towards the galaxy center. You won't be able to see it, but it's there.
I wonder if the EHT will ever try to capture an image of a black hole that's positioned sideways to our PoV, like the one from Interstellar
Let’s just assume there was nothing at all obstructing our line of sight to a/this SMBH, would we be able to see light at a visual wavelength? I’m very science illiterate so apologies if this isn’t phrased properly.
Easy words: would it be possible for us to literally see this if nothing was in the way.
Stunning, it amazes me this thing exists like it’s a real thing which exists.
With the jump from the first pictures to this in such a short space of time, just imagine what’s to come over the next few years/decades
What secrets are you hiding from us Sagittarius A ?!
Where all light goes to die...
Cool
event horizon-chan has a big juicy hole
The breaks and angles remind me of the geometrical poles on our own gas giants. This is amazing work.
Well I learned something new today. My understanding was The Event Horizon was an unrecordable phenomenon. That's interesting as heck. Great share.
Alright. unzips Let’s light this candle.
id love to see an AI trained on this telescopes data to try and deconvolute the image of this black hole.
i bet it can do a better job than anyone else.
The brushstrokes of creation
Stupid question but I thought our galaxy as a whole is orbiting Sag A. If it’s 1000 less massive that M87, why don’t we orbit M87. Or is Sag A only coincidentally in the center? Greeting from Germany!
Looks like it's always twirling, twirling, twirling towards something
my new desktop background, thank you. my current desktop background is something similar
A question about "sucking in" matter. Wouldn't the generation of energy and the discharge of matter and photons result in a kind of "friction" that would slow some portion of the matter in the accretion disk? My understanding is the black holes do pull in mass as they age.
I want to be awed but all I see is a wonky lava lamp nightlight
That looks equally frightening and pleasing.
Is it interesting that the polarized light is making a "whorl" like a fingerprint, and not a spiral? Is that known thing or...?
Thank you for taking the time to share and explain this, my mind is blown! :)
Where does it lead!?
The center looks so.. bright
FYI our Sun Orbits this thing
Wow, so it still short circuits my brain even with an actual picture! This is still one of the coolest things I've ever seen though. Thanks for the post! Gonna make it my wallpaper.
Also as to why the gravity of black holes is so immense - it’s because you can get closer to their center. In op’s example of if the sun became a black hole, nothing would change for us and our orbit. This is true, because gravity is measured to the center of a mass. However, if the sun shrank from what it is now to ~2 miles, you’d be able to get soooo much closer to that center, that you’d be able to feel the gravity more and more. If you tried to get close now, you’d just be in the sun. But if you shrink it, the surface is farther down and you can get closer and feel more gravity
A black hole lets you feel all the gravity
Well it doesn't look very black.
I wish they had a huge resolution image :(
That is the most beautiful thing I've ever seen 😭
This is absolutely incredible!!!
Anybody else rocking out to Muse in their head right now?
Designporn. Beautiful logo!
Odd question, but why are orange, red, and yellow colors used to represent the measurement's intensity when visualizing data about black holes? Did the M87 image use these colors arbitrarily and are just the standard now, or is there a more interesting reason?
My lord, are you there my lord?
Whee!
Just go thru it I dare you
That lady got it pretty good with that data compilation
If you look at it long enough, it is gonna suck you in
Radio astronomer here! This is a big deal (and I'm colleagues with those who led the research!). For those who want an overview, here is what's going on!
What is this new result about?
Sagittarius A* (Sgr A* for short) is the supermassive black hole (SMBH) at the center of our Milky Way, and weighs in at a whopping 4 million times the mass of the sun and is ~27,000 light years away from Earth (ie, it took light, the fastest thing there is, 27,000 light years to get here, and the light in this photo released today was emitted when our ancestors were in the Stone Age). We know it is a SMBH because it's incredibly well studied- in fact, you can literally watch a movie of the stars orbiting it, and this won the teams studying it the 2020 Nobel Prize in Physics. So we knew Sag A* existed by studying the stars orbiting it (and even how much mass it had thanks to those orbits), and a picture of it was released in 2022, but it was missing an important piece of information- polarization.
Polarization is often called the "twist" of light, but really what it tells you is the direction of the waves traveling at you- is it straight up and down like waves in an ocean, or perpendicular to that, or somewhere in between? (Most people know polarized light best via sunglasses and tilting their head at water to see how the light changes.) In science, polarization is important because it contains important information on magnetic fields present- which might not sound exciting, but magnetic fields are hard to measure and understand! I wrote an article once for Astronomy on magnetic fields in the universe here, but the TL;DR is magnetic fields tell us a ton about the environment the light came from, such as from the event horizon around Sag A* in this case!
So, what the team did since the release of the Sag A* photo is take more data, and decipher that polarization information! So pretty! But that's not all- the magnetic field is quite structured, which implies we might have a hidden jet at the center of our Milky Way! An astrophysical jet is when material is beamed along an axis- sometimes this material can travel at relativistic speeds and be very long, but I do not think this is the case here. Instead, it seems most likely that the jet would be fairly weak in its outflow and "only" a few light years across... but still, if this holds, it would revolutionize our understanding about our galaxies and SMBH in general!
Didn't we already have polarization information for a black hole? Why is this one such a big deal?
We do! That black hole is M87*, which is located 53 million light years from Earth and is 7 billion times the mass of the sun (so over a thousand times bigger than Sag A*). It might sound strange that we saw this black hole first, but there were a few reasons for this that boil down to "it's way harder to get a good measurement of Sag A* than M87*." First of all, it turns out there is a lot more noise towards the center of our galaxy than there is in the line of sight to a random one like M87- lots more stuff like pulsars and magnetars and dust if you look towards the center of the Milky Way! Second, it turns out Sag A* is far more variable on shorter time scales than M87*- random stray dust falls onto Sag A* quite regularly, which complicates things.
However, it's because we have the M87* data already that this is so interesting- specifically, what is striking is how Sag A's magnetic field is REALLY similar to M87's. That is pretty wild because we can see a relativistic jet being launched from it- there is literally a Hubble picture- so even though these black holes are so different in mass, if their magnetic fields are so darn similar it really implies there might be a jet in Sag A* as well that we just aren't aware of.
I thought light can't escape a black hole/ things get sucked in! How can we get information from one/ launch jets from one?
Technically these pictures are never of the black hole, but from a region surrounding it called the event horizon. This is the boundary that if light crosses when going towards the black hole, it can no longer escape. However, if a photon of light is just at the right trajectory by the event horizon, gravitational lensing from the massive black hole itself will cause those photons to bend around the event horizon! As such, the photons never cross this important threshold, and are what we see in the image in this "ring."
Second, it's important to note that black holes don't "suck in" anything, any more than our sun is actively sucking in the planets orbiting it. Put it this way, if our sun immediately became a black hole this very second, it would shrink to the size of just ~3 km (~2 miles), but nothing would change about the Earth's orbit! Black holes have a bigger gravitational pull just because they are literally so massive, so I don't recommend getting close to one, but my point is it's not like a vacuum cleaner sucking everything up around it. (see the video of the stars orbiting Sag A* for proof).
As for the jets- this is not material crossing the event horizon, but instead dust that comes very close and gets launched outwards. We actually do NOT understand the full details of this- it's an active area of astrophysical research- but it does have to do with the magnetic fields present around the black holes. And one reason why today's results are so valuable!
How was this picture taken?
First of all, it is important to note this is not a picture in visible light, but rather one made of radio waves. As such you are adding together the intensity from several individual radio telescopes and showing the intensity of light in 3D space and assigning a color to each intensity level. (I do this for my own research, with a much smaller radio telescope network.)
What makes this image particularly unique is it was made by a very special network of radio telescopes literally all around the world called the Event Horizon Telescope (EHT)! The EHT observes for a few days a year at 230–450 GHz simultaneously on telescopes ranging from Chile to Hawaii to France to the South Pole, then ships the data to MIT and the Max-Planck Institute in Germany for processing. (Yes, literally on disks, the data volume is too high to do via Internet... which means the South Pole data can be quite delayed compared to the other telescopes!) If it's not clear, co-adding data like this is insanely hard to do- I use telescopes like the VLA for my research, and that already gets filled with challenges in things like proper calibration- but if you manage to pull it off, it effectively gives you a telescope the size of the Earth!
To be completely clear, the EHT team is getting a very well-deserved Nobel Prize someday (or at least three leaders for it because that's the maximum that can get the prize- it really ought to be updated, but that's another rant for another day). The only question is how soon it happens!
This is so cool- what's next?!
Well, I have some good news and some bad news. The bad news is we cannot do this measurement for any other supermassive black holes for the foreseeable future, because M87* and Sag A* are the only two out there that are sufficiently large in angular resolution in the sky that you can resolve them from Earth (Sag A* because it's so close, M87* because it's a thousand times bigger than a Sag A* type SMBH, so you can resolve it in the sky even though it's millions of light years away). You would need radio telescopes in space to increase the baselines to longer distance to resolve, say, the one at the center of the Andromeda Galaxy, and while I appreciate the optimism of Redditors insisting to me otherwise there are currently no plans to build radio telescopes in space in the coming decade or two at least.
However, I said there was good news! First of all, the EHT can still get better resolution on a lot of stuff than any other telescope can and that's very valuable- for example, here is an image of a very radio bright SMBH, called Centaurus A, which shows better detail at the launch point of the jet than anything we've seen before. Second, we are going to be seeing a lot in coming years in terms of variability in both M87* and Sag A*! Black holes are not static creatures that never change, and over the years the picture of what one looks like will change over months and years. Right now, plans are underway to construct the next generation Event Horizon Telescope (ngEHT), which will build new telescopes just for EHT work to get even better resolution. The hope is you'll get snapshots of these black holes every few weeks/months, and be able to watch their evolution like a YouTube video to then run tests on things like general relativity. That is going to be fantastic and I can't wait to see it!
TL;DR- we now have a polarized picture of the black hole at the center of the Milky Way, which indicates there might be a hidden jet. Black holes are awesome!!!