Terrifying Mystery of the Universe’s Biggest Black Hole

[00:00:01]Astronomers found a black hole that seems way too big for its age. By everything we know about space, it shouldn't have had enough time to grow.

[00:00:10]And the more scientists studied it, the weirder it got.

[00:00:14]You see, the first black hole we managed to photograph was at the center of the galaxy Messier 87.

[00:00:21]That space behemoth contains about [music] 6 billion times the mass of our sun. And now, meet TON 618. It contains about 66 billion suns worth of mass.

[00:00:33]Astronomers call such monsters ultramassive black [music] holes. The scale of this black hole is difficult to picture. Even if you took all the stars in the Milky Way galaxy and packed them into a single black hole, it would still not be enough.

[00:00:48]But, there's a problem. Nobody really knows how big a black hole can actually get. For a long time, astronomers believed that there had to be some limit. After all, growing a black hole isn't easy, let me tell you. To keep feeding, it needs gas. This gas falls toward a black hole and heats up to incredible temperatures. This makes it start blasting out radiation, which pushes back on the rest of the gas trying to fall in. This makes it harder for the black hole to grow.

[00:01:19]So, scientists call this phenomenon the Eddington limit. Basically, the universe's way of putting the brakes on a starving black hole.

[00:01:27]But, this limit doesn't actually determine how big a black hole can eventually get. And as far as we know, there may be no maximum size at all.

[00:01:36]So, in theory, you could keep merging black holes together over and over again, making them larger each time.

[00:01:43]Just like rolling a snowball that keeps picking up more snow.

[00:01:46]Most of the time, though, black holes grow through a process [music] called accretion, which is just a fancy word for feeding.

[00:01:53]Plus, black holes don't usually swallow matter the way most people imagine. Gas doesn't simply fall straight into the hole. Instead, it forms a huge spinning disc around it. Inside that disc, particles are constantly crashing into one another like in a giant cosmic bumper car arena.

[00:02:12]During every collision, some particles gain energy and get pushed farther away from the black hole. Others, less lucky, lose energy and slowly drift inward.

[00:02:22]After countless impacts, some particles lose so much energy that they can no longer resist the black hole's gravity.

[00:02:29]They spiral closer and closer until they reach a region called the innermost stable orbit. You can think of it as the last safe lane before the final drop.

[00:02:39]Outside this boundary, matter can still orbit. Inside it, there's no stable path left. When something crosses that line, it's basically on a one-way trip toward the event horizon, also known as the point of no return.

[00:02:55]Now, despite how dramatic this process sounds, all of this happens very slowly.

[00:03:00]It takes millions of years for a black hole to gain a modest amount of mass.

[00:03:05]And that's exactly why TON 618 is such a headache for astronomers.

[00:03:10]Somehow, despite all these limits and bottlenecks, it managed to grow into a monster containing about 66 billion suns worth of mass.

[00:03:20]Now, remember that other problem black holes have? Yep, they can't eat as much matter as they want. When huge amounts of gas pile up around a black hole, they form a fast-spinning disc. Inside that disc, particles are moving at incredible speeds and constantly crashing into each other. All those collisions create friction, and friction [music] creates tons of heat.

[00:03:43]In fact, the disc gets so hot that it starts glowing. It can actually shine brighter than an entire galaxy.

[00:03:51]And that's how astronomers many supermassive black holes. From billions of light-years away, they often look like tiny points of light that completely outshine the galaxies around them.

[00:04:02]Those objects are called quasars.

[00:04:04]For a long time, scientists didn't even know what quasars [music] were. They looked like stars, but something was off. Much later, astronomers realized those were supermassive black holes feeding at the center of galaxies.

[00:04:19]But the light helping us find black holes also creates a problem for them.

[00:04:24]The disc can become so bright that its light starts pushing [music] outward.

[00:04:28]And because light carries energy, it can actually push on things. So, the brighter the disc becomes, the stronger that pressure gets. Eventually, it starts pushing gas away from the black hole instead of letting it fall in.

[00:04:41]It's like trying to pour more water into a funnel while a powerful fan is blowing upward from the bottom.

[00:04:48]In other words, if too much gas builds up, the black hole's feeding disc becomes brighter. The brighter it gets, the more material it pushes away.

[00:04:57]Once a balance is reached, the black hole [music] can't eat any faster. And no matter how much extra gas you throw at the black hole, >> [music] >> it can only grow at its own pace. The rest gets blown back into space.

[00:05:09]So, the question remains, how did this ultramassive black hole manage to find and swallow so much material to grow to such gargantuan proportions [music] in a relatively short time?

[00:05:21]And TON 618 may not even be unique.

[00:05:25]Astronomers have found another black hole that seems to break the same rules.

[00:05:30]Recently, the James Webb Space [music] Telescope spotted an object called QSO 1 around 13 billion light-years away. That means we see it as it looked when the universe was only about 700 million years old. At the center of QSO 1 sits a black hole with a mass roughly 50 million times greater than the sun.

[00:05:51]But the black hole itself isn't the biggest surprise. It's the galaxy around it. Astronomers thought they had a pretty good idea of how supermassive black holes form. Usually, it goes like this. A galaxy forms first, then stars begin to appear.

[00:06:06]>> [music] >> Much later, some of those stars collapse into black holes. And over millions or billions of years, those black holes grow by feeding on gas, dust, [music] stars, and sometimes even other black holes. Eventually, a large galaxy ends up with a large black hole at its center. The two are supposed to grow together.

[00:06:28]Well, QSO1 doesn't seem to know that.

[00:06:31]The galaxy looks relatively small and undeveloped, while the black hole already appears unusually massive. It's like finding a finished skyscraper standing in the middle of a town that's still being built. Even in today's universe, where we see some truly enormous black holes, they usually don't dominate their host galaxies to this [music] extent.

[00:06:53]This discovery is especially important because astronomers have managed to measure the black hole directly. In the past, we could only estimate a black hole's mass in the early universe, relying on indirect methods or assumptions [music] based on nearby galaxies. Scientists weren't sure whether those assumptions still worked when the universe was young.

[00:07:13]Well, QSO1 gave us a chance to check this.

[00:07:17]Using James Webb's NIRSpec instrument, researchers measured how fast gas was moving around the black hole. The stronger the black hole's gravity, the faster that gas should move. That's how they got the mass of about 50 million suns.

[00:07:32]The James Webb telescope keeps finding similar examples. Astronomers call them little red dots, small distant [music] objects that seem to contain surprisingly massive black holes. James Webb has already found hundreds of them.

[00:07:46]The deeper scientists look into the early universe, the more often those objects show up. And according to many current models, some of them [music] simply shouldn't have had enough time to grow that large.

[00:07:58]So, how do they do it?

[00:08:01]Well, nobody knows for sure. One idea is that some giant black holes form directly from enormous clouds of gas, skipping several stages of the normal process.

[00:08:12]Some scientists think dark matter might have somehow helped these black holes bulk up way faster than they should have. But honestly, nobody knows yet.

[00:08:22]But what if galaxies don't always create supermassive black holes? What if, at least in some cases, supermassive black holes appeared first? If that's true, then some of the earliest galaxies may not have built their central black holes at all. Instead, those black holes may have helped build the galaxies around them.