# Would Voyager return to the solar system if stopped? **URL:** \ **Category:** Factual Questions\ **Created:** [September 8, 2016, 4:53pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341 "2016-09-08T16:53:23Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [September 8, 2016, 4:53pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/1 "2016-09-08T16:53:23Z")
If it were possible to stop the Voyager I craft from moving away from the solar system, i.e. stop it in reference to the location of the sun, would it eventually return to the solar system? Is the solar system, particularly the sun, itself, the closest, most gravitationally attractive thing it’s closest to? What about Jupiter? ---
**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:** [September 8, 2016, 5:38pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/2 "2016-09-08T17:38:38Z")
Yes, it’s still far closer to the Sun than to any other star. As for Jupiter, at those distances, you might as well just call the Sun and Jupiter the same location. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [September 8, 2016, 10:33pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/3 "2016-09-08T22:33:14Z")
The moment you let go of it it’d start falling into towards the Sun. IOW, it’d be in a new orbit around the Sun. An orbit whose aphelion is however far out Voyager is/was when you let go. And whose perihelion depends on how exactly you got it to zero speed, where all the other perturbation sources happen to be when you let go, etc. IOW, you just created a new artificial comet. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 8, 2016, 11:10pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/4 "2016-09-08T23:10:03Z")
Why would it not be drawn back into the sun? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [September 8, 2016, 11:12pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/5 "2016-09-08T23:12:34Z")
> [@White SIFL](#): > > Why would it not be drawn back into the sun? You mean now? Because its inertia is such that its trajectory is outbound, not inbound. Basically, it’s going too fast, Dude. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [September 8, 2016, 11:24pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/6 "2016-09-08T23:24:02Z")
> [@White SIFL](#): > > Why would it not be drawn back into the sun? It would, if it was stopped in space with respect to the Sun, and there were no other objects nearby. But, nothing’s prefect, and a planet’s gravity, or a passing star would perturb it enough to go into a highly eccentric orbit. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [September 9, 2016, 12:32am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/7 "2016-09-09T00:32:31Z")
> [@White SIFL](#): > > Why would it not be drawn back into the sun? In a bit more detail … Right now the distance from Voyager 1 back to the Sun is roughly 20.3 billion kilometers. See [Where Are They Now? - NASA Science](http://voyager.jpl.nasa.gov/where/index.html) The Sun is roughly 695,000 km in radius. See [Sun - Wikipedia](https://en.wikipedia.org/wiki/Sun) That ratio is roughly 29,200 to 1. Think hitting a billiard ball from a half mile away. It would only take a tiny error in release, or a tiny influence from any planet’s gravity or just random fluctuations in interplanetary gas or dust or solar wind, to be enough to make Voyager miss the Sun on the way back in. And once it misses the first time, it’ll keep orbiting essentially forever. Perhaps it’ll be perturbed enough on some future orbit to hit the Sun or get ejected, or get wrapped around Jupiter or … ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 9, 2016, 5:19am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/8 "2016-09-09T05:19:19Z")
It’d change its name to V’Ger, though. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [September 9, 2016, 7:24am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/9 "2016-09-09T07:24:44Z")
First it has to find its way back to the Alpha Quadrant. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [September 9, 2016, 11:21am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/10 "2016-09-09T11:21:58Z")
> [@CC](#): > > If it were possible to stop the Voyager I craft from moving away from the solar system, i.e. stop it in reference to the location of the sun, would it eventually return to the solar system? Here’s a good picture to put it in perspective - but note its logarithmic ! > **[Oort cloud](https://en.wikipedia.org/wiki/Oort_cloud#/media/File:PIA17046_-_Voyager_1_Goes_Interstellar.jpg)** > > The Oort cloud (/ɔːrt, ʊərt/), sometimes called the Öpik–Oort cloud, is theorized to be a vast cloud of icy planetesimals surrounding the Sun at distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years).\[note 1\] The concept of such a cloud was proposed in 1950 by the Dutch astronomer Jan Oort, in whose honor the idea was named. Oort proposed that the bodies in this cloud replenish and keep constant the number of long-period comets entering the inner Solar System—where they The cloud i... Voyager 1 is 100 AU out , where jupiter is at 8 AU … Sol’s influence runs out to near Alpha Centauri , with the picture showing the limit of the Oort cloud (any thing which happens to be floating through space when Sol comes along and starts to be dragged around with Sol … is it a cloud ? its actualy THEORETICAL and hasnt been detected. ) at 200,000 AU… Voyager will start to enter the Oort cloud distance in 300 years time…So Its still in the zone which the planets clean up… anything inside the Oort Cloud will be sucked in ? While the Oort cloud is distant enough to remain out there… but be dragged around with Sol. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [September 9, 2016, 11:51am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/11 "2016-09-09T11:51:02Z")
> [@panache45](#): > > First it has to find its way back to the Alpha Quadrant. I thought we were in Sector ZZ9 Plural Z Alpha? ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 9, 2016, 12:11pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/12 "2016-09-09T12:11:18Z")
> [@LSLGuy](#): > > In a bit more detail … > > Right now the distance from Voyager 1 back to the Sun is roughly 20.3 billion kilometers. See [Where Are They Now? - NASA Science](http://voyager.jpl.nasa.gov/where/index.html) > > The Sun is roughly 695,000 km in radius. See [Sun - Wikipedia](https://en.wikipedia.org/wiki/Sun) > > That ratio is roughly 29,200 to 1. Think hitting a billiard ball from a half mile away. It would only take a tiny error in release, or a tiny influence from any planet’s gravity or just random fluctuations in interplanetary gas or dust or solar wind, to be enough to make Voyager miss the Sun on the way back in. > > And once it misses the first time, it’ll keep orbiting essentially forever. Perhaps it’ll be perturbed enough on some future orbit to hit the Sun or get ejected, or get wrapped around Jupiter or … Thanks for the detailed explanation. I didn’t realize the other planets would have that much effect. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [September 9, 2016, 5:04pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/13 "2016-09-09T17:04:27Z")
> [@White SIFL](#): > > Thanks for the detailed explanation. I didn’t realize the other planets would have that much effect. There was a program that was making my social media mentions a lot a year or two ago…the name of which I can’t recall now…that let you model the orbits of the planets and see how their gravity affects a fictional planet(oid) that you insert into orbit around the sun. Compared to the sun, all of the planets together don’t have a GREAT gravitational influence, but they have enough (especially Jupiter) to pull things around enough to put it off whatever course you try to set it on. Even a millimeter off of the intended course will have large consequences, at interplanetary distances. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [September 9, 2016, 6:29pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/14 "2016-09-09T18:29:51Z")
That’s it exactly. Percentagewise Jupiter’s influence is tiny. But when any induced error bigger than tiny_tiny_tiny is enough to make Voyager fall into an orbit instead of directly impacting the Sun, … well … Jupiter is plenty big enough for that. As is the collective influence of all the other stuff floating around out there. ---
**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\ **Post date:** [September 9, 2016, 10:28pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/15 "2016-09-09T22:28:56Z")
A secondary question, if all forward momentum of Voyager was stopped how long would it take to fall back past the Earths orbit and how fast would it be going? I imagine it would take a long time to build up speed as it started ‘falling’ back. ---
**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:** [September 10, 2016, 1:39am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/16 "2016-09-10T01:39:27Z")
It’d be darned close to the same amount of time that it took to fall all the way up there to begin with. Slightly longer, since it’s not quite stopped right now. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 10, 2016, 1:41am UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/17 "2016-09-10T01:41:02Z")
> [@Isilder](#): > > Here’s a good picture to put it in perspective - but note its logarithmic ! > > [Oort cloud - Wikipedia](https://en.wikipedia.org/wiki/Oort_cloud#/media/File:PIA17046_-_Voyager_1_Goes_Interstellar.jpg) > Voyager 1 is 100 AU out , where jupiter is at 8 AU … I’m afraid _you_ didn’t note it was logarithmic. Jupiter is actually at 5.2 AU. > [@](#): > > Sol’s influence runs out to near Alpha Centauri Not in the direction of Alpha C. In that direction, the Sun’s influence is about halfway. In other directions, it extends out until some other star is closer (more or less). > [@](#): > > , with the picture showing the limit of the Oort cloud (any thing which happens to be floating through space when Sol comes along and starts to be dragged around with Sol … is it a cloud ? its actualy THEORETICAL and hasnt been detected. ) at 200,000 AU… The Oort Cloud is a bunch of planetesimals leftover from the formation of the Solar System. Instead of being gobbled up by planets, they got ejected from the inner System by Jupiter into very long, elliptical orbits. Once they got out there, apparently the gravity of the Milky Way as a whole circularized their orbits, so they didn’t come directly back into the inner System. But every once in a while, a close passing star perturbs some their orbits and sends them back in. They are then called long period orbits. There are some objects that are too far out to be considered part of the Kuiper Belt. Sedna and a few others orbit completely outside the 50 AU boundary of that belt. They’ve sometimes been called Inner Oort Cloud objects. But I expect that designation to change once we discover the Ninth Planet. They’ll be a class of objects in resonance with 9P (we don’t have a name for it yet). > [@](#): > > Voyager will start to enter the Oort cloud distance in 300 years time…So Its still in the zone which the planets clean up… anything inside the Oort Cloud will be sucked in ? While the Oort cloud is distant enough to remain out there… but be dragged around with Sol. The Kuiper Belt, which is not labeled on that chart, has been there for over 4 billion years without being sucked in. It won’t be sucked in any time soon, or for that matter, ever. Not as a group anyway. Some members occasionally get perturbed into orbits in the inner Solar System and are then short period comets. ---
**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\ **Post date:** [September 10, 2016, 11:05pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/18 "2016-09-10T23:05:02Z")
> [@Chronos](#): > > It’d be darned close to the same amount of time that it took to fall all the way up there to begin with. Slightly longer, since it’s not quite stopped right now. I see, thank you. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 10, 2016, 11:18pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/19 "2016-09-10T23:18:40Z")
> [@dtilque](#): > > The Oort Cloud is a bunch of planetesimals leftover from the formation of the Solar System. Instead of being gobbled up by planets, they got ejected from the inner System by Jupiter into very long, elliptical orbits. Once they got out there, apparently the gravity of the Milky Way as a whole circularized their orbits, so they didn’t come directly back into the inner System. But every once in a while, a close passing star perturbs some their orbits and sends them back in. They are then called long period orbits. Just noticed an error in the above. The last sentence should be " They are then called long period **comets**". ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [September 11, 2016, 12:19pm UTC](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341/20 "2016-09-11T12:19:04Z")
Fall time is a special case of Kepler’s Third Law. Using a [calculator](http://www.calctool.org/CALC/phys/astronomy/planet_orbit) for that and plugging in 67.5 AU (Half of Voyager 1’s solar distance) as the semi-major axis gives about 554.5 years. Quite a bit more than the 39 years since launch. Lots of different factors including gravity assist as well as current velocity. For Voyager 2, it’s only 413.4 years. Cf. [long term comets](https://en.wikipedia.org/wiki/List_of_long-period_comets). E.g., Comet C/1986 E1 (Shoemaker) has a semi-major axis of 67.5284 AU and a period of 555 years. [Next page](https://boards.straightdope.com/t/would-voyager-return-to-the-solar-system-if-stopped/765341.md?page=2)