# Can you find your way home from far FAR away? **URL:** \ **Category:** Factual Questions\ **Created:** [December 10, 2008, 4:50pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570 "2008-12-10T16:50:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Geekboy](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@Geekboy](https://boards.straightdope.com/u/Geekboy)\ **Post date:** [December 10, 2008, 4:50pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/1 "2008-12-10T16:50:02Z")
A semi-common theme in sci-fi is the dreaded “Joe Blow gets abducted by aliens, traipses across the galaxy having various and sundry adventures, and then finds his way home, happily ever after, blah blah” plot. But - how the hell WOULD you find your way back home? Is there any piece of information that the average mope can arm him or herself with that would show a friendly and helpful spacefaring race how to get a lost soul back to earth? It obviously needs to use easy to find landmarks (spacemarks?) and use only universal values for distance and direction. Ideally this would be something you could just memorize, but in a pinch I would accept something with written instructions that you could keep in your pocket or around your neck or whatever. ---
**Author:** ![Meurglys](https://avatars.discourse-cdn.com/v4/letter/m/258eb7/32.png) [@Meurglys](https://boards.straightdope.com/u/Meurglys)\ **Post date:** [December 10, 2008, 5:01pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/2 "2008-12-10T17:01:45Z")
If you knew what the constellations looked like from Earth, if you saw them anywhere else, you’d know that you were in line with Earth and, depending if they looked larger or smaller, either behind you or ahead of you… ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [December 10, 2008, 5:36pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/3 "2008-12-10T17:36:43Z")
Constellations look mostly the same if you’re as far away as Proxima Centuri. While that’s our closest neighbor, that’s still a hella long way from Aunt Suzy’s house. I think you’d need a handful of very distinctive stars, and then some highly accurate way to triangulate them. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 10, 2008, 5:44pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/4 "2008-12-10T17:44:31Z")
If you’re still within our Galaxy, then your best navigation beacons would be the Magellanic Clouds and the various globular clusters. If you know the relative positions of several of those, you could get back into the general vicinity of Sol, and go by the constellations from there. This would probably require more information than the average “Joe Blow” would have, but it might not be out of reach of a skilled amateur astronomer with a good eye. Or, of course, you could just hack into the aliens’ navigation computer and backtrack. EDIT: > [@](#): > > Constellations look mostly the same if you’re as far away as Proxima Centuri. With two notable exceptions, of course, at least one of which should be familiar to someone from anywhere on Earth. And a few nearby stars like Sirius would also be in notably different locations. ---
**Author:** ![fiddlesticks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiddlesticks/32/18129_2.png) [@fiddlesticks](https://boards.straightdope.com/u/fiddlesticks)\ **Post date:** [December 10, 2008, 5:44pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/5 "2008-12-10T17:44:38Z")
This is the responsibility of the stellar cartography division. Presumebly in the far future, your iSpacePhone will have a MilkyWayMap app so you can plot your way home. ---
**Author:** ![Rhubarb](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@Rhubarb](https://boards.straightdope.com/u/Rhubarb)\ **Post date:** [December 10, 2008, 5:45pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/6 "2008-12-10T17:45:34Z")
In theory, all you need are 3 points, e.g., the positions of our sun and one other star in relation to the galactic center. In actuality, you’d want the locations of multiple stars to aid in navigation, as a trivial error could land you very far from home. Of course, the real sticking point would be translation errors between you and your extraterrestrial buddies. Look what happened with one of the Mars probes from a Metric to English unit conversion error. And that was just inside our solar system between two members of the same species. ---
**Author:** ![Geekboy](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@Geekboy](https://boards.straightdope.com/u/Geekboy)\ **Post date:** [December 10, 2008, 5:51pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/7 "2008-12-10T17:51:30Z")
The problem there is, of course, how do you find your marker stars in the first place? If you are in the other arm of the galaxy, you cant find anything over here. Which is why, of course, the constellation idea would not work at all. You would need pulsars or some other unique radio phenomena, that is pretty clear. The problem remains, however, how to describe the distance and direction from them. Same species? I hardly think that anyone who uses Imperial units counts as the same species 🙂 > [@Rhubarb](#): > > In theory, all you need are 3 points, e.g., the positions of our sun and one other star in relation to the galactic center. In actuality, you’d want the locations of multiple stars to aid in navigation, as a trivial error could land you very far from home. > > Of course, the real sticking point would be translation errors between you and your extraterrestrial buddies. Look what happened with one of the Mars probes from a Metric to English unit conversion error. And that was just inside our solar system between two members of the same species. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [December 10, 2008, 5:52pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/8 "2008-12-10T17:52:49Z")
What about getting a tat based on the [Golden Record](http://voyager.jpl.nasa.gov/spacecraft/goldenrec1.html)from the Voyager probes? > [@](#): > > The diagram defines the location of our sun utilizing 14 pulsars of known directions from our sun. The binary code defines the frequency of the pulses. ---
**Author:** ![Sigmagirl](https://avatars.discourse-cdn.com/v4/letter/s/c89c15/32.png) [@Sigmagirl](https://boards.straightdope.com/u/Sigmagirl)\ **Post date:** [December 10, 2008, 5:53pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/9 "2008-12-10T17:53:26Z")
Why is it men will never ask directions? ---
**Author:** ![Geekboy](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@Geekboy](https://boards.straightdope.com/u/Geekboy)\ **Post date:** [December 10, 2008, 6:07pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/10 "2008-12-10T18:07:37Z")
Ah - now we are getting somewhere. The pulsar map and the hydrogen “key” for the timing should be enough. Does a tattoo have enough resolution to keep the binary data legible at the size needed to fit conveniently on your body? Or are we looking at a market for groovy medallions here? Also - how would that map work if it is only 2D? The directions would only work if you happened to be on exactly the right plane. Or are the relative DISTANCES also correct? They dont explain that part very well. Any Voyager geeks out there? > [@Rhythmdvl](#): > > What about getting a tat based on the [Golden Record](http://voyager.jpl.nasa.gov/spacecraft/goldenrec1.html)from the Voyager probes? ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [December 10, 2008, 6:12pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/11 "2008-12-10T18:12:37Z")
> [@Sigmagirl](#): > > Why is it men will never ask directions? Sweetheart, can you please keep quiet? I’m trying to concentrate. Hey, I think I recognize that asteroid! ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 10, 2008, 6:18pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/12 "2008-12-10T18:18:07Z")
> [@](#): > > The problem there is, of course, how do you find your marker stars in the first place? If you are in the other arm of the galaxy, you cant find anything over here. Which is why, of course, the constellation idea would not work at all. That’s why I recommended globular clusters, instead: You can see those pretty much across the Galaxy. They also have the advantage that they’re visible to the naked eye, or with only a small telescope: No other sensors or other devices needed. For the language barrier, you wouldn’t need to describe the distances at all: Directions would be enough, if you have enough of them (at least four or five; a dozen would be better). And directions you can communicate just by pointing. ---
**Author:** ![Geekboy](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@Geekboy](https://boards.straightdope.com/u/Geekboy)\ **Post date:** [December 10, 2008, 6:29pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/13 "2008-12-10T18:29:26Z")
How does one describe a cluster, tho? “It’s the big one that looks like a duck” “Qxxyxmo duck?” There is a better explanation of Rhythmdvl’s (thanks, you devil, you) Pioneer/Voyager directions here: > **[Pioneer plaque](https://en.wikipedia.org/wiki/Pioneer_plaque#Relative_position_of_the_Sun_to_the_center_of_the_Galaxy_and_14_pulsars)** > > The Pioneer plaques are a pair of gold-anodized aluminium plaques that were placed on board the 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft, featuring a pictorial message, in case either Pioneer 10 or 11 is intercepted by intelligent extraterrestrial life. The plaques show the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft. > The Pioneer 10 and 11 spacecraft were the first human-built objects to achi... Jewelry, anyone? > [@Chronos](#): > > That’s why I recommended globular clusters, instead: You can see those pretty much across the Galaxy. They also have the advantage that they’re visible to the naked eye, or with only a small telescope: No other sensors or other devices needed. > > For the language barrier, you wouldn’t need to describe the distances at all: Directions would be enough, if you have enough of them (at least four or five; a dozen would be better). And directions you can communicate just by pointing. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [December 10, 2008, 6:31pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/14 "2008-12-10T18:31:45Z")
> [@Geekboy](#): > > Ah - now we are getting somewhere. The pulsar map and the hydrogen “key” for the timing should be enough. Does a tattoo have enough resolution to keep the binary data legible at the size needed to fit conveniently on your body? Or are we looking at a market for groovy medallions here? It wouldn’t need to be in binary, necessarily — the only reason that the distances on the Voyager record are expressed in binary and in units of hydrogen frequencies is that we don’t know what units or base number systems the aliens would use. If you’re going to be reading it, you could just tattoo in something like “236.7 milliseconds” instead. > [@Geekboy](#): > > Also - how would that map work if it is only 2D? The directions would only work if you happened to be on exactly the right plane. Or are the relative DISTANCES also correct? They dont explain that part very well. Any Voyager geeks out there? As far as I can tell, the lengths of the lines correspond to the distances of the pulsars; the angles of the lines are chosen by demanding that the distance of the pulsars above & below the galactic plane are to scale. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [December 10, 2008, 6:35pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/15 "2008-12-10T18:35:18Z")
[All you need is a T-shirt](http://www.thinkgeek.com/tshirts-apparel/unisex/sciencemath/6e90/?cpg=ab). ---
**Author:** ![Geekboy](https://avatars.discourse-cdn.com/v4/letter/g/51bf81/32.png) [@Geekboy](https://boards.straightdope.com/u/Geekboy)\ **Post date:** [December 10, 2008, 6:40pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/16 "2008-12-10T18:40:35Z")
But - how do you explain a “millisecond” (or a second, for that matter) to an alien? Any earthy units are going to be essentially useless. But the T-SHIRT idea! Damn! And already made! > **[Pioneer Plaque Shirt II | Zazzle](http://www.zazzle.com/pioneer_plaque_shirt_ii-235022880358779453)** > > Pioneer Plaque On T Shirt I still want a groovy medallion, tho. > [@MikeS](#): > > It wouldn’t need to be in binary, necessarily — the only reason that the distances on the Voyager record are expressed in binary and in units of hydrogen frequencies is that we don’t know what units or base number systems the aliens would use. If you’re going to be reading it, you could just tattoo in something like “236.7 milliseconds” instead. ---
**Author:** ![Sigmagirl](https://avatars.discourse-cdn.com/v4/letter/s/c89c15/32.png) [@Sigmagirl](https://boards.straightdope.com/u/Sigmagirl)\ **Post date:** [December 10, 2008, 6:42pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/17 "2008-12-10T18:42:36Z")
> [@tdn](#): > > Sweetheart, can you please keep quiet? I’m trying to concentrate. Hey, I think I recognize that asteroid! You should. You’ve driven past it nine times. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [December 10, 2008, 7:03pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/18 "2008-12-10T19:03:12Z")
The short answer is NO. Average Joe Blow would not be able to find his way back to earth if he were dropped somewhere else in the galaxy. What are you going to say? Uhhhh…it’s a kind of yellowish star…not too big, not too small. It’s sort of out on the outer arms of the galaxy. There’s nine planets (or eight and a sort-of planet). That’s not going to be much help. ---
**Author:** ![Sofis](https://avatars.discourse-cdn.com/v4/letter/s/e5b9ba/32.png) [@Sofis](https://boards.straightdope.com/u/Sofis)\ **Post date:** [December 10, 2008, 7:12pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/19 "2008-12-10T19:12:38Z")
> [@Geekboy](#): > > But - how do you explain a “millisecond” (or a second, for that matter) to an alien? Any earthy units are going to be essentially useless. If you have any time-keeping device, you can show them. If you don’t, you can demonstrate a unit of length (for example, I can define a metre by stating that I am 1.78 m tall), and then express the speed of light using that unit of length (it’s about 3\*10^8 m/s) and derive a unit of time from there. Of course, that requires you to be able to communicate, but if you’re patient, the aliens can probably teach you their language. For that matter, if this alien species is more advanced than humans (it would have to be) they probably have better planet imaging methods, or have sent a network of unmanned probes to map solar systems. They may well have our solar system in their databases, and if you can describe it in sufficient detail, they may be able to figure out which one it is. That is, you can “ask for directions” :). ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [December 10, 2008, 7:17pm UTC](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570/20 "2008-12-10T19:17:13Z")
> [@fiddlesticks](#): > > This is the responsibility of the stellar cartography division. Presumebly in the far future, your iSpacePhone will have a MilkyWayMap app so you can plot your way home. Hello , this is OnUniverse, our indicators show you are either lost in the Delta Quadrant, or are being devoured by a Bugblatter beast, would you like us to activate Constello-Jack or send assistance? [Next page](https://boards.straightdope.com/t/can-you-find-your-way-home-from-far-far-away/476570.md?page=2)