The galaxy far, far away is vast and full of wonders, but not all of it has been explored. There is a whole region of this rich galaxy that has yet to be fully discovered, and while the Star Wars films have not mentioned it yet (we're waiting on Rian Johnson for that), many of the books in the new canon do. What are we talking about? None other than the "unknown regions."
Cue the force theme here, please. Also, SPOILERS COMING for the books Aftermath: Empire's End, Thrawn, Tarkin, and the game Star Wars: Battlefront II.
What are the unknown regions?
We're glad you asked! They are exactly what the name suggests — entire regions of the GFFA that are unexplored. The line that marks the crossing into the unknown regions is known, what lies beyond that line is not.
So is it like wild space?
Similar, but no. The unknown regions at the very least have a marker on the map of Star Wars. Wild space is completely off the edge of the map, and it's where you'll find places like Mortis from The Clone Wars and the ancient Lasat world of Lira San from Star Wars: Rebels.
It sounds similar.
It might, but the unknown regions are much more present in the canon than wild space. Just forget wild space for now.
Where are the "unknown regions" mentioned?
One of the first instances came in James Luceno's novel, Tarkin, which chronicled the future Grand Moff's rise through the imperial ranks. His nemesis in that book says that the Emperor's rule would soon affect "everyone between here and the unknown regions."
Is that it?
Of course not, that was just the beginning. Both Timothy Zahn's Thrawn and Chuck Wendig's Aftermath: Empire's End make it clear that Emperor Sheev Palpatine was obsessed with the region. Thrawn (real name Mitth'raw'nuruodo) is a Chiss, and the Chiss Ascendancy is based in the unknown regions. Though we're first told in Thrawn that the future white uniformed rebel killer was in exile, we discover that particular story to be a lie. Thrawn was sent to the "known" regions of space by the Chiss to take the measure of them. During the book, Thrawn has many secret meetings with Palpatine, who takes an immediate liking to the Chiss and is partially why Thrawn's rise to Grand Admiral happens so quickly.
What were they meeting about?
Thrawn was helping Palpatine to map the unknown regions. By the end of the book, Thrawn's protege/assistant is sent out to the Chiss Ascendancy to learn from them. This will hopefully be addressed in the Thrawn sequel, Thrawn: Alliances.
What did Palpatine do with all of Thrawn's information?
He added it to the vast amount of information that he was already gathering. Palaptine had sent explorers to the unknown regions almost as soon as he sent Mace Windu flying out of his window. He sensed a great Dark Side presence there, and he became obsessed with finding out what it was, among other things.
Why was he so obsessed? Was it because he was the Emperor and wanted to keep his new secure society safe from the threat?
That's cute. Does that sound like him? Any other Dark Side presence would be a threat to him. Don't forget, the Sith go by the rule of two, and he had Vader at his side. Any other Force sensitives either needed to be eliminated, or twisted to his own ends, like the inquisitors on Rebels. Besides, if he's already conquered all of the known galaxy, why stop there?
What happened to the explorers he sent out?
Was all of that worth it?
That depends. Palapatine had several "observatories" spread throughout the galaxy. You get to explore one of them in the new Battlefront game, playing as Luke Skywalker himself. The observatory in that game is on a planet called Pillio, but another one of these installations was on the planet Jakku.
Ah, I know that one! It's where Rey is from!
Indeed she is, but we're not there yet. Before the desert planet became a graveyard for dead imperial ships, Palaptine had an observatory there. The sole purpose of it was to generate maps of the unknown regions.
Are you making this up?
How dare you! Aftermath: Empire's End tells us just how important the planet Jakku was to Palpatine. His observatory sent out several probes to the unknown regions right before the Battle of Endor, and his flagship, Eclipse, ventured there (without him, of course) soon after. Following the machinations of Galius Rax and the Battle of Jakku, imperial mainstay Rae Sloane was given coordinates to guide her through to the unknown regions, with a mission to rendezvous with the Eclipse.
What happened to her?
We don't know yet, but we do know that what little remained of the Empire after the Battle of Jakku fled into the unknown regions as well.
Alright, I get it. Sounds cool. Why should I care?
Well, for one thing, the amount of word service given to the regions in the books is at the point where they seem to be building up to something. It could be something new, or laying a connection to something we've already seen.
Already seen in one of the films?
Exactly. In terms of the new trilogy, we know that both the First Order and Supreme Leader Snoke came from the unknown regions.
Snoke! Was he the Dark Side presence that the Emperor was sensing?
He very well could have been. Starkiller Base was also built out there. Some of the recent comics (Poe Dameron, especially) have even gone so far as to call the unknown regions "First Order Space." The true beginnings of the First Order and the mystery of just who the kriffin' kark Snoke is are all tied to the unknown regions.
Wait, remember Rey? She was marooned on Jakku, a planet very important to Palpatine — could he somehow be involved in her past? Is Palpatine Rey's father? Did he whip her up in one of those observatories, using Anakin Skywalker's blood, some extra midichlorians, Luke's severed hand, and a recipe from the old Darth Plagueis handbook on Virgin Births?
I don't want to brag, but I'm awesome.
You obviously do want to brag. Anyway, you can see where the constant build up of unknown region history could play a very big part in the Star Wars stories we're going to be getting — from the history of Snoke and the First Order in Star Wars: The Last Jedi, to more about Thrawn in Star Wars: Rebels and Thrawn: Alliances, and of course the completely new Rian Johnson Star Wars trilogy. I'd say there's a decent shot that those stories could take place there.
Wait, that's not going to be a Knights of the Old Republic trilogy?
As cool as that idea is, Johnson has said that it won't be. In any case, the unknown regions could also provide an external threat for the GFFA. We're so used to civil war, but a new species could easily come out of those regions and attempt to rule over everyone, Rebel and Imperial alike. It would be interesting to see the First Order have to fight alongside the Resistance and the New Republic... it would be something like the Yuuzhan Vong stories of the old EU... but a bit better, perhaps.
The Yuuzha... what?
Picture the Independence Day aliens merged with the tentacle monster from the Watchmen comic. They're biological, techno-phobic, force resistant, and they terraform Coruscant. At one point they... okay, I've said way too much. Not gonna happen. Forget them.
No problem. You've won me over, consider me an unknown regions convert. I can't wait for more!
You're in luck, then. Star Wars: The Last Jedi comes out on December 15th. We may find out more then. If not, then the novels will almost certainly pick up the baton.