In The Expanse, what happens if you enter the "back" side of the ring? I have not read the books. In the TV series, it seems like no one even thinks to ask.

Maybe it is like this Stargate explanation to basically the same question.

If the Station ring were not on the edge of a bubble, then maybe you would just come out through the other side of the Station ring.

-> O                                 O ->
   O <-                           <- O 

But with the presence of the bubble on the Station side, that explanation is not possible.

Uranus        Neptune                                   Station
                                                         /    \
       -> O                                             O ->   |
                                                         \    /
                                                         /    \
          O <-                                     ? <- O      |
                                                         \    /
  • Deleted my answer, but the way you ask the question.... its really hard too understand you. also there was an attempt by a guy to enter the ring at a very high speed. it ended up badly. apparently the "correct" way to enter is butt end of the ship first at a specific speed.
    – Cherubel
    Commented Feb 25, 2019 at 10:42
  • I don't think "butt end" matters so much as "at a certain speed." (IIRC, the Belter capital ship went in forwards.) The Roci went in backwards because they were using their main engine to decelerate to a safe speed after taking evasive maneuvers to escape shenanigans in real space.
    – Steve-O
    Commented Feb 25, 2019 at 14:47
  • @OP I don't think the TV show has said anything about going in one side versus the other. The books may or may not have more to say on this, but I haven't read them myself.
    – Steve-O
    Commented Feb 25, 2019 at 14:52
  • I think this question may require a new accepted answer. The Dragon Tooth comic is authorised and addresses this directly.
    – Valorum
    Commented May 30 at 18:10

3 Answers 3


We don't know.

I've searched through all the books starting with Abaddon's Gate (which is when the humans first travel to the Ring) and none of them depict an event in which a ship or probe is sent through the "back" of the Ring.

The books describe the Ring as

an artificially sustained Einstein-Rosen bridge. You go through the Ring, you don’t come out the other side here.

Abaddon's Gate, p. 137

An Einstein-Rosen bridge is a type of wormhole.

I would guess that an object passing through the Ring from the back (i.e. traveling toward the Sun) would either (a) be destroyed as soon as it flew between the interior of the Ring or (b) would pass through it harmlessly and without effect (i.e. it would not enter the Ring space and would continue traveling toward the Sun in local space).

I don't think such a ship would enter the Ring space because we know that the Ring is directional when passing from the Ring space into a local solar system. For one, there is no way to pass through the "back" of a ring gate from the Ring space -- the "space" between the Rings on the boundary of the Ring space is a void (light blue in the TV show, total blackness in the books) which ships cannot enter. Furthermore, the Ring Station has a direct line of sight to each Ring's local star (e.g. the Sun) which makes it possible for the Ring Station to

blow up the Ring's local star and "autoclave" the whole system.

The Ring must be directional when traveling from the Ring space to the local solar system for this to be possible. If the Ring is directional when traveling from the Ring space to the local solar system, therefore, it stands to reason that it is most likely directional when traveling from the local solar system to the Ring space. We can't rule it out for sure, though.

I suspect the reason no one ever tried to enter the Ring from the "back" is that there is almost nothing in the solar system beyond the Ring. The Ring is just beyond the orbit of Uranus, and the only human colony beyond that is on Triton, one of Neptune's moons. Even then, a ship traveling from Neptune toward the Sun wouldn't necessarily pass by the Ring in that direction -- if Neptune and the Ring are on opposite sides of the solar system then the Ring would actually be even farther from Neptune than any other human colony in the solar system.

Given the Ring network's purpose as a "road" network between solar systems it makes perfect sense to place a Ring at the outer limits of a solar system and allow travel through it only to and from the side facing the local star -- that's the only direction ships will ever realistically want to travel into and out of. Allowing travel through the Ring in only that one direction is not really a limitation.

  • Thanks. I was especially interested in someone familiar with the books to see if there were an answer in there. It would make sense to me if someone had at least tried sending a probe through the ring from the back side. Maybe we can assume they did, and nothing "important" happens, as in both of your guesses (a) and (b). Related, I wonder if you are positioned in the local solar system with the ring between you and the sun, what do you see? Maybe a void, like the edge of the Ring space. Surely not light from the sun, which has gone into the Ring space. Commented Feb 25, 2019 at 18:35
  • @alex.jordan Happy to help. I was somewhat surprised that no one had mentioned sending a probe through the back of the Ring, either, but I guess no one wanted to bother with the effort. I'm not sure what you'd see looking into the back of the Ring, either -- my guess is a void because, as you pointed out, the light from the Sun would have gone into the Ring space. That said, the Ring produces distortions so it's possible you'd see a distorted view of the Sun.
    – Null
    Commented Feb 25, 2019 at 18:41
  • Do you have a source on ships not being able to enter the space between/beyond the rings in the books ? If not, I think your argument on why the rings should be directional from the space to the system doesn't hold, and with it, the assumption that it must also be directional in the other way. Sure the Death Star Laser needs to go in one direction, but that doesn't forbid things to travel the other way. Commented Jan 23, 2023 at 2:43

The authorised comic series The Expanse: Dragon Tooth (by BOOM! Studios) discusses this.

Avasarala: You'll forgive the expression, but what happens when someone flies a ship up its backside?

Admiral: Nothing. The dark side is inert. We don't fully understand how that works yet. But every probe we've sent through from that side simply passes through the ring without effect. It's basically just a big empty hula hoop in space.

enter image description here
Dragon Tooth #9

  • 2
    Hi, welcome to SF&F. Although it would be good if you established some degree of canonicity for this source, it would be far, far better to actually describe the answer instead of just vaguely indicating "it's over there somewhere."
    – DavidW
    Commented May 30 at 17:22
  • 4
    I've taken the liberty of adding a panel and a quote from the comic. I'm pretty sure this is the scene you're referring to.
    – Valorum
    Commented May 30 at 17:54
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  • OP here. Most likely I will change this to the accepted answer. I do think that this leaves questions though, perhaps that the comic just didn't feel the need to detail. Like what would happen if a saucer-shaped ship entered the back side while spinning? One side would be passing through the back side, but the other side could now have net motion through the ring in the regular forward direction. Would the ship be ripped apart? Maybe the ring stops all such awkward motion and straightens you out as you enter the back side? Commented Jun 1 at 22:41

The wiki says the ring is a wormhole.

However if it is a wormhole, it's probably not an accurate depiction of one, as according to Space.com.

In two-dimensional diagrams, the wormhole mouth is shown as a circle. Seen in person, a wormhole would be a sphere. A gravitationally distorted view of space on the other side can be seen on the sphere's surface.

In other words, it should not be a ring, but a sphere, and therefore as I understand it, no direction for entry.

As far as I have read in the books, to my recollection it is never stated what happens when entering one side versus the other, but I haven't read them all.

Therefore, given what we know of wormholes and no other information that I'm aware of, I'd say you'd reach the ring station the same by entering the ring from either side.

  • I disagree that you'd enter the Ring space when entering the Ring from the "back" side. Please see my answer for my reasoning.
    – Null
    Commented Feb 25, 2019 at 17:51
  • @Null personally, since we agree it's all supposition, I think the best answer would include all possibilities. If you want you can add to your answer with information from my answer.
    – Kai
    Commented Feb 25, 2019 at 17:57
  • I did include all possibilities in my answer: "...it stands to reason that it is most likely directional when traveling from the local solar system to the Ring space. We can't rule it out for sure, though." I just think that a bidirectional Ring is the least likely of possibilities.
    – Null
    Commented Feb 25, 2019 at 18:02
  • To me personally, your answer reads more like a rebuttal to my answer than a standalone answer. It has good information about details from the books, but I think it could be improved a bit by rewording a little to make it less a rebuttal to another answer and more just a listing of the possibilities and arguments for or against, if that makes sense.
    – Kai
    Commented Feb 25, 2019 at 18:31
  • I started drafting my post and had reached my conclusion before you posted your answer. I would've posted my answer earlier but it look me a long time to exhaustively search books 3-7 in case I'd missed a minor incident of a ship or probe entering the Ring from the back. I did not write it as a rebuttal to yours, though I understand that it might look like that from your perspective.
    – Null
    Commented Feb 25, 2019 at 18:37

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