Imagine we could open a wormhole or a jump point to a new star system. How soon would it be possible to have an accurate map of the major bodies in that system? In sci-fi, this sort of information seems to be easily available through "scanning the system" but what does that actually mean? What sort of scanners or sensors could we use to detect orbital bodies?

Using our own solar system as an example... we have made most of our discoveries through optical observation, this has taken hundreds of years, but we could imagine that time would be much shorter with modern telescopes and techniques. But unless we some had other sort method of detection, this would still be a very long process.

I would imagine that bodies closest to the star/s would be the fastest to discover, with the amount of time dramatically increasing as we move to the outermost planets. Maybe an entirely accurate map would never be feasible (just as we are uncertain of planets outside of Neptune in our own system, or we were uncertain of the number of moons Pluto had until the New Horizons flyby). Would there be optimal places to emerge to make this process faster? Like in the OORT cloud range for example, or extremely close to the star/s? If a completely accurate map isn't possible, how accurate of a map would we need for travel through the system?

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    $\begingroup$ You'll want to restrict "orbital bodies" quite a bit. For instance, we've mapped almost none of the Oort Cloud, and there are still plenty of minor bodies we have yet to find. Also, would you want a full ephemeris to be constructed for each body, and if so, to what degree of accuracy? $\endgroup$
    – HDE 226868
    May 3, 2017 at 14:02
  • $\begingroup$ How accurate a map do you want? Are you wanting to know just orbital characteristics or do you want surface detail? What level of resolution do you care about? Can you launch probes? Can your probes create wormholes too? $\endgroup$
    – sphennings
    May 3, 2017 at 14:08
  • $\begingroup$ I'm imagining a system where the point in which you emerge is fixed, more of a jump point than a wormhole per se, so you would not be able to create additional wormholes. As far as accuracy, I'm thinking just the most basic of detail, e.g. "This system has 5 planets, three terrestrial, two gas giants. The orbit of planet 1 is 75 standard days, orbit of planet 2 is 400 standard days, etc. Planet 1 is .5 AU from the star, planet 2 is 1.5 AU from the star... etc" $\endgroup$
    – johny5w
    May 3, 2017 at 14:16
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    $\begingroup$ Unless you can scan through the sun (which i find unlikely), you may want to start from a position vertical to the orbital plane of the major bodies. You should get a decent view from there, provided your equipment has a fine enough resolution. If you start near a major body orbiting the sun, the shadow of this body, the sun, and all other bodies will ahve to be taken into account. After that, again things are limited to the quality of your scanners mostly. $\endgroup$
    – Burki
    May 3, 2017 at 15:15
  • $\begingroup$ Related: (worldbuilding.stackexchange.com/questions/14066) $\endgroup$
    – gilgamec
    May 4, 2017 at 13:47

2 Answers 2


It depends on a number of things.

What are we mapping?

Even before we map anything, we need to know exactly what we are mapping. Large, easily visible stars? Planets? Moons? Asteroids? Find your cutoff first. Local stars are easy to map, generally speaking, since they tend to be fairly stable, and radiate energy on their own. Planets are harder to map, since they don't radiate energy on their own. Moons are harder still, and mapping every asteroid would be nigh-on impossible, if for no other reason than there are so many of them.

Where are we mapping from?

If we're on a planet with atmosphere, that atmosphere will get in the way (as will the planet, its moon if it has one, and so forth). If we're mapping from space, but near a planet, we'll still have to deal with the planet being in the way. On the other hand, if we're mapping from a point of "dead space", far from the system, we'll have a full panorama spread out in front of us; not having to wait for day/night cycles, or worse seasonal cycles, will save a lot of time.

What are we using?

If all you have to map celestial bodies is a basic telescope, it'll take years of careful study, regardless of anything else. If we're using tiny satellites carrying preprogrammed cameras, it will take weeks of taking images, transmitting them, and sending back new coordinates to map - and likely months or years of travel to get close enough to anything to get anything useful. If we are on a scientific vessel designed for just that purpose, however, it's likely we have countless imaging devices for all spectrums of energy, software to parse the images directly, and scientists to put all that information together - all of which will save a lot of time. A major part of the reason it took hundreds of years to map our system is technology; until the last 100 or so years, we barely had anything past telescopes. And now, most new discoveries are made through breakthroughs in technology.

So, how long?

Forever. No matter how good your equipment is, you'll always have a little more to map. That's just the way of things; stars, planets, and space debris move around, and sometimes it takes a long time before a new celestial body is revealed.

However, if you have good equipment, good software, a good vantage point, and limit yourself to mapping easily visible local planets, and maybe a few large moons, you probably could map a system within seconds. As you extend the boundaries of your search, you can map more and more; it's up to you when to stop.


It depends on the avaiable resources and political will for doing the mapping.

All they have to do is to send a swarm of satellites carrying not-too high magnification but high field of view (https://en.wikipedia.org/wiki/Field_of_view#Astronomy) telescopes to spot the brighter bodies, and some high-resolution and high pointing accuracy telescopes to track the detected ones and determine their deatils and orbital elements. All telescopes outfitted with instruments working in IR, UV, Visible or even x-ray band.

The pointing telescopes would have Strong engines too, to place them appart and thus ensure faster parralax measuements.

After the biggest bodies are mapped, orbital perturbation analysis could be used to detect new ones.

Of course complete mapping is impossible, it is almost impossible to discover all the sub-100m asteroides and micro moons of gas giants.

But as a questimate, I think that the complete mapping of the significant bodies of a solar system similar to ours would minimally take 5 months. Since outer system bodies have very long orbital period (Pluto: 248 years), one have to observe them for a time to get meaningful orbital information.

If we only send a small telescope (NASA budget is low), it can possibly take hundred of years.


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