Back in February 2026, a couple  of SciShow’s producers got a special behind-the-scenes tour at the American Museum of Natural  History in New York City.

And while they were there, they  heard a pretty spectacular story. You know those education videos  they show in planetariums?

The ones that send you flying  through the solar system as you learn what astronomers know about all  the planets, asteroids, and so on? Well, while astronomers were in  the middle of making one of those… narrated by Pedro Pascal, by the way… they accidentally discovered something  new at the edge of our solar system. A weird “S” shape in the Oort Cloud.

No, not that cool “S” every kid learns to doodle. I wish it was like that! But this space “S” is still  very cool in its own way.

So let’s dive into the details of that  story shared with our producers that day. And we’ll have a little help  from one of the astronomers, too. [♪ INTRO] In the mid-1900s, a Dutch astronomer  named Jan Oort was busy studying comets. And he quickly realized that,  based on their calculated orbits, some of them took a very long  time to go around the Sun.

So in 1950, he wrote a paper  hypothesizing the existence of a massive comet reservoir that was very, very far away from most of the bodies we consider  to be a part of the solar system. And by “very, very far away”, I mean  the inner edge of the cloud that bears his name sits at about 1,000  astronomical units, or au from the Sun. The average distance between the Earth  and the Sun is defined to be 1 au.

And Pluto, previously known as  the furthest planet from the Sun, never gets farther than 50 au away. Meanwhile, astronomers think the outer  edge is a whopping 100,000 au distant. One light year is only 63,000 au!

The moment a spacecraft left the Oort Cloud, it would already be a third of  the way to the next star over: the Alpha Centauri system. But why is this cloud there in the first place? To help us unpack the science…plus  the discovery she helped make… we spoke with Dr.

Jackie Faherty, a curator at the American  Museum of Natural History. It's all the leftover material from  when the solar system first formed. So you can think of it kind of like the sawdust… the junk around the corners that comes  around after you build something.

Because all those proverbial sawdust bits  are so tiny, so far away, and also so cold, they are extremely hard  for our telescopes to spot. There’s so little evidence of them, the  Oort Cloud is still technically theoretical. Even though astronomers are pretty  darn sure it has to be there.

The Oort cloud is a little frustrating…. It basically remains a  theorized collection of objects. What we have had, which is important,  is that you get long period comets that come into the inner solar  system, and then they head out… So we see things not while they're  in the Oort cloud structure at these far off distances.

But actually when they come in, they  do their little lap around the sun, but it could take them 100,000  years to go around the sun. Astronomers are pretty much always on  the lookout for new Oort Cloud bodies. Including ones that aren’t comets.

For example, in 2015,  astronomers found Leleakuhonua, an asteroid that takes 32,000  years to orbit the Sun. But how did Leleakuhonua and all  that other stuff get out there? Did it form out there, billions of years ago, and just miss out on spiralling down  toward the Sun to help make the planets?

Astronomers suspect “no”. See, when our solar system  was younger, the planets hadn’t yet settled into their final  configuration we now know and love. Jupiter did quite a bit of  moving around in particular, and its massive gravity scattered  smaller rocks all over the solar system.

The entire mass of the solar system minus the Sun, but Mercury, Venus, Earth, Mars, Saturn,  Uranus, Neptune, Pluto, the Kuiper belt, the whole asteroid belt, all of that  mass can actually fit inside of Jupiter… Jupiter is a behemoth. So I often call  it the bouncer of the solar system. Jupiter chucked some of these rocks inwards where they eventually got eaten by the Sun.

Some of them were thrown fast enough  they left the solar system all together. Some of them survived, scattered out to the far reaches of the Oort Cloud  on really oblong orbits. Meanwhile, things outside the solar system may be involved in shaping the Oort Cloud as well.

Namely, the galactic tide. This is what gives the Oort  Cloud its nice spherical shape. It's a beautiful word, isn't it?

The galactic tide…So the same way  that the Sun holds on to all of us… we're also held in the Milky Way. We're not just on some wandering  path through the cosmos. At the center of our galaxy,  there’s a supermassive black hole.

So just like the planets in  our solar system orbit the Sun, almost everything in the galaxy  orbits this one massive object. And just like the Sun tugs on planets, the Milky Way tugs on our whole solar system. It's not a tug you feel  right now as we sit and talk.

It's not a tug that, like, when  you throw something in the air, the galactic tide is going to  yank it more than the Earth will. That's not the case. This tug, the galactic tide, really  only gets noticeable when you’re super far from the Sun, where the Sun’s  gravitational tugging is way weaker.

And at the outer edges of our solar system, that galactic tide can start picking off  bodies that are only loosely bound to the Sun. Like the comets in the Oort Cloud. Sometimes I think of it like Jenga.

You know, in Jenga, you kind  of look for the loose thing. You look for something that'll give a little bit. And the things in the outer  part of the solar system are really the loose Jenga pieces.

And the galactic tide pokes at  them and then can yank them away. The galactic tide affects the  outer portion of the Oort Cloud. But inside 10,000 au or so, the Sun  has a strong enough gravitational pull that bodies get to act like  those Jenga tower pieces you try to poke out and they just don’t budge.

That also means the Inner Oort Cloud is  shaped like a disk, instead of a sphere. And for a long time, astronomers thought the Oort Cloud had just these two structures. But then came a piece of science  communication narrated by Pedro Pascal.

Many of us have sat through a planetarium show, be it as an elementary school  student on a field trip, or because we’re just huge nerds like that. And Jackie Faherty was busy  curating a new show for her museum. This is the first time ever  that a planetarium production led to a scientific discovery.

It was a big deal to see science visualization  come to life the way it did in this. For one section of the video, she  wanted to feature a spectacular event that’s going to happen in the far-flung future: a rogue star is going to run  into the Inner Oort Cloud. A star named Gliese 710 is going  to fly through our solar system.

And by that, I mean it's going  to fly through the Oort cloud in a little over a million years….this  is something I’m obsessed with. In order to really show people the  visuals of what this could look like, we needed the very best model of the Oort cloud that anyone in the world had ever made. Through her search, she landed on a model made by an astronomer named David Nesvorny.

In other words, something that was made for scientists to use,  not science communicators. To find the best way to visualize the models, Faherty had to play around a bit in the  planetarium, and by looking at data in 3D. Which in case you didn’t know, isn’t  something astronomers tend to do.

We plot in two dimensions a lot. It's just easier and faster and  it's more of the classic tools. But if you do that, you lose a third  dimension that is maybe critical.

When we were inside of the planetarium, staring at a couple of iterations  through of looking at it, and myself… and the two directors were like,  oh, well, there's an S inside of it. They first thought the S might be an artifact  of how they were displaying the data. Not an actual phenomenon out in space.

But better safe than sorry: they brought  it up to the guy who made the model. Nesvorny was like, no, no,  no, I think that's real. And that became the exciting  moment during the space show where we realized we had  stumbled onto something that was inside of the model that was  grounded in observations, but had not yet been realized because  it needed a three-dimensional structure and the teasing out that we were  doing with basically a VFX expert.

In fact, the S had been hiding  in astronomers’ data for years! But why was it there at all? Faherty and Nesvorny teamed up with yet more astronomers to do some actual research.

And they figured out it’s not from other  stars nudging around our Oort Cloud. Instead, it’s a result of that beautifully-named galactic tide Faherty mentioned earlier. And it’s the fact that our solar system is tilted relative to the plane of the galaxy  which makes all the difference.

You've been on these Gravitron  machines that spin you, spin you, spin you, and then the floor drops. And then they tilt you around. And so then you're tilted to the  right and you're tilted to the left.

And your head might feel a little  bit different than your toes. Like you will feel the force different  depending on what your tilt is with respect to the thing that's yanking on you. The galactic tide actually has a  stronger force at certain angles, at certain inclinations, which is  why it can win in the tug of war between the Sun and the galactic tide.

There are these sweet spots where  the galactic tide will win over. To make sure they really  understood what was going on, the team used NASA supercomputers to  simulate the objects moving around in the Oort cloud, thinking about  forces like the galactic tide and the even weirder Kozai-Lidov effect. Basically, when you have two  things orbiting a third body, they still gravitationally  interact with each other.

And because of this interaction, the orbit of the smaller thing  ends up changing quite a bit. For example, its orbit might start  off pretty circular and very inclined, meaning its orbit is tilted  relative to the other’s. But because of the interaction  and some momentum shenanigans, it’ll switch to being stretched  out and elliptical but less tilted.

At least, this is what Jackie and  her collaborators think is happening to create that S shape, based on  a combination of existing theory and the computer simulations they ran. But with so few identified Oort Cloud objects, it’s hard to be super sure about  this spiral and where it comes from. More observations could help  confirm the shape they found, and learn about the Oort Cloud’s history.

And lucky for us, we have a new  telescope that can help with that. Just two weeks before we filmed this episode, the Rubin Observatory started its primary mission: to use the largest digital  camera ever made to take pictures of the whole southern sky every  few nights… for the next 10 years! Each night will generate 20 terabytes  of data for astronomers to peruse, which is equivalent to taking 6.6  million photos on your iPhone.

But even with all that power,  Rubin is only expected to find about 12 new Oort Cloud  objects…barely more than one a year… because it’s just that hard to find them. Perhaps, as we get new data,  there will be new planetarium shows to help visualize the cosmos and find other structures like the Oort Cloud spiral. I know it’s a long shot, but I’m  still holding out for the cool S. [♪ OUTRO]