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If you were flying along in your spacecraft somewhere in our solar system and then a large, stable wormhole suddenly opened and you flew into it and were whisked away to some distant location in the galaxy, would you be able to figure out where you were?

Obviously, a large stable wormhole is exceedingly unlikely, and then there's the matter of the power of your onboard computer and telescope(s). But all that aside, I'm wondering if it would be even theoretically possible to figure out where you were, since the constellations would probably be unrecognizable and you wouldn't have an understandable flight path.

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    $\begingroup$ We know a lot more than just constellation patterns as observed from Earth. $\endgroup$ – Carl Witthoft Jan 30 '17 at 14:00
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    $\begingroup$ Why the downvote? This seems like a perfectly good question about identifying your location in the Milky Way based on observables. $\endgroup$ – zephyr Jan 30 '17 at 16:48
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Assuming you had access to the relevant astronomical catalogues and data, then yes it would.

Looking at constellations would of course be hopeless and most stellar catalogues only contain star positions for a relatively small volume in our Galaxy. However, there are classes of object inside and outside the Galaxy that would do the job.

A displacement in our own Galaxy would produce a notable displacement in the positions of local group galaxies, like Andromeda and M33, with respect to distant quasars that define the ICRS coordinate reference frame.

Providing one had the means (i.e. telescopes) to make the necessary observations, then it should be relatively straightforward to reconstruct your position in the Galaxy from the new apparent positions of recognisable local group galaxies.

Further possibilities are offered by globular clusters and pulsars.

The colour-magnitude diagrams and chemical compositions of globular clusters are all subtley different, which should enable their identification. They are also spread in a roughly spherical distribution around the Galaxy.

Radio pulsars have unique pulse shapes and timing properties that make them readily identifiable. A possible/probable problem is that many pulsars would be rendered invisible by the change in viewing angle.

In both these cases, a map of the revised spatial locations with respect to the ICRS should enable you to work out where you are compared with the position of the Earth now. I am unsure what precision could be achieved, but then we are unsure of our present location with respect to distance to the Galactic centre by a few percent.

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If a spaceship travels through a space warp into an unknown region of space or gets lost some other way the navigators should look for familiar objects. Fortunately space is transparent. Very transparent. Very, very, very transparent. The thinnest and most transparent vacuum made on Earth is like a sheet of lead compared to the densest, dustiest part of interstellar space.

From a clear spot you can see forever, so to speak.

So the navigators should look for bright objects in the visible and other parts of the electromagnetic spectrum. They should take the spectra of the 10 or 100 objects that are brightest in each of various bands of visible light, radio, infrared, ultraviolet, X Rays, gamma rays etc., and compare them to the spectra of the 10 or 100 brightest objects in those bands as seen from Earth or their home world wherever it is.

The hope will be that you haven't traveled too far from known space and some at least of the objects observed in the new location will match those on the list as seen from the home world. All you need to do is observe three known objects and then from differences in their apparent magnitudes and the angles between them as seen in your new location and as seen from your home world you can calculate your new position. Modern astronomical instruments that are vital for interstellar navigation can measure such angles to incredible precision.

And the 10 or 100 brightest objects visible in any band of the spectrum from any location will usually be at a great variety of distances. Some just a few light years away, some hundreds, some tens of thousands, some millions of light years away, some hundreds of millions, etc. The ones that are far enough away will still be among the brightest objects in that band no matter where you go within our galaxy.

So you can be Lost in space in the sense of not having a way to get home, but so long as you don't jump millions of light years or something you can't get Lost in space in the sense of not being able to figure out where you are.

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  • $\begingroup$ There are very large known structures in the intergalactic space (the Great Wall, some billion light-year voids, etc) which could be easily identified by a systematic mapping of the galaxies. $\endgroup$ – peterh says reinstate Monica Jan 31 '17 at 3:56

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