Is Voyager I outside our solar system?

Probably not yet. But it's on the cusp. And part of what makes this entire process really, really interesting is that, by the very nature of this whole experiment, we don't know exactly what will happen when Voyager I does cross that imaginary boundary line. But, as Rebecca Rosen explains on The Atlantic, we do have some pretty good theories.

Some cosmic ray particles enter the heliosphere and we can see them here from Earth. But a slower type has a hard time entering the heliosphere. Last month, the sum of those slower particles, suddenly ticked up about 10 percent, "the fastest increase we've seen," Stone says. But an uptick does not mean Voyager has crossed over, though it does mean we're getting close. When Voyager does finally leave and enter the space "out there where all the particles are," the level will stop rising. The rising itself means that Voyager is not out there, yet. "But," cautions Stone, "we don't know. I mean this is the first time any spacecraft has been there." Since nothing's ever been there before, we don't know what it will look like, which makes it a little hard to recognize "it" at all. "That's the exciting thing," he continues.

This is the most exciting kind of science—the sort where we really don't know the answers and we're on the cusp of learning something truly, wonderously new. Stay tuned.

Read Rebecca Rosen's full article at The Atlantic


  1. What’s going to happen? “Something Wonderful”

    Vger will break into the heliosphere, which initiate a signal beacon (there is also an automated beacon buried on the far side of the moon which we could have uncovered to the same effect, but never did). The beacon will be detected by the overseers of the Universal Transit System. This will initiate their opening of a monolithic star gate near Saturn (Jupiter if you’re watching the movie) which will allow the first persons into it instant transfer across the galaxy via its transit system.

    I thought this had all been covered 42 years ago? :P

    1. There’s also the option of encountering a race of machine intelligences and coming back as a sentient cloud. I wouldn’t worry about that for the next four Voyagers, though.

    1. I don’t have a copy editor. I think I’ve fixed the problems here, but for future reference, typos are bound to happen and it’s more helpful if you let me know exactly what you’ve spotted that needs fixing. 

  2. Having passed the minimum galactic standard for a sentient species, we suddenly lose our protected status, and are immediately subjected to the advertisements of 100 million worlds.. until we can get on the galactic do-not-call list.

  3. Years ago, I read a somewhat sad short story, premised on the idea that every solar system capable of producing intelligent life was surrounded by a shell or force field impenetrable from the outside, but trivially breached should a manufactured item pierce it from the inside, removing the shell. The sadness arose from the discovery that only a few others had managed to break their shells, and they had all long ago retreated to the event horizons of large black holes, leaving behind requests that once it wasn’t so lonely out there, that they get a wake up call so they could join the party.

    1. “The Crystal Spheres” by David Brin. It’s a great and sad story with a very hopeful ending.

  4. What does Voyager do to keep the radio signal oriented back towards earth? Is there some sort of orienting beacon from Earth? Just curious if the “turbulent” transition out of the heliosphere poses any real threat to communicating back to Earth.

    1. Good questions, and there is NO beacon from Earth, I would bet that there’s on-board stellar calibration instruments, even at those distances the stars wouldn’t have budged enough to screw up the Voyagers’ navigation, which is basically a straight line.

      In fact, using Alpha Centauri as a beacon, they recently rotated Voyager 1 90º to point the instruments sideways and try to detect solar wind falling back on itself.  They’ll soon do the same with Voyager 2.

    2. @niktemadur:disqus follow @NASAVoyager2:twitter on Twitter. It tells you in real time the various things that Voyager 2 does (including stellar calibration which it just did two hours ago), as well as occasional updates on Voyager 1.

      1. Guide Lockstar (α Lyrae, Vega) reacquired.
        END magnetometer calibration roll maneuver: MAGROLAB

        There it is!  So I just missed it by a couple of hours… um, a couple of hours +13 hours and 35 minutes (light distance from Earth).

  5. Maggie, why did you call it an “imaginary boundary line”, right before a quote that describes exactly how physical it is? The edge of the solar system is defined by the heliopause. It’s as real any any halocline.

    1. Because the full article goes on to say this: 

      “It would be nice, fulfilling even, if at the edge of the heliosphere there were, well, an actual edge, a boundary between our bubble and the cosmos. But, it’s probably not going to be so cut and dry. ‘The boundary,” Stone postulates, “will not be an instantaneous thing. [Voyager] won’t suddenly be outside.” Rather, the exit will be turbulent, “a mix of inside and outside.'”

      1.  I wouldn’t consider blurry and imaginary synonymous, but I guess that’s your call.

  6. Voyager 1 entered the heliopause almost 10 years ago, keeping me fascinated with tales from the the fringes of the heliosphere, I find this stage of the missions more amazing than the planet flybys.  These guys are beyond the Kuiper Belt, aren’t they?
    But I wouldn’t call it “outside our solar system” just yet, I’d reserve that label for beyond the Oort Cloud, and that’s a long way off.  A very long way.

    OK, so the Pioneers are contentedly chugging along, when a blur whooshes and zooms by.  “What the hell was that?  Oh, it’s them newfangled Voyagers”.
    Then the Voyagers are cruising along, when “ZOOOM!” and “What the hell was that?”  Ah yes, the New Horizons, get off my lawn.

    1. I think I agree with you but isn’t the traditional definition of “our solar system” is that where the sun still has an influence? Beyond the heliopause the solar winds cease so could be argued as outside the system. But, IANAAP.

      1. Our sun still has an enormous influence in the Oort Cloud, every single object there is gravitationally bound to AND orbits Sol.

        Also, there is the likelihood that we are in a binary system with a brown dwarf, most definitely part of our system yet beyond the heliopause.  But Nemesis is hypothetical, indirectly inferred by the periodic extinctions on Earth.

  7. Why has nothing overtaken Voyager on its way to the Heliopause, Dagnabbit? This Future sucks, I want a better one.

      1. Full cost of Voyager Program: Just over $900 M.
        Annual Global Perfume Trade: Around $10 B.

        Lets get some more money from the private sector for bridges and roads, and continue to advance humanity’s knowledge of the universe, eh? 

      2. “Rocket ships are exciting, but so are roses on a birthday…”, da de dum dum dum, etcetera… “I guess I’m just an old fashioned spaceman” – Leonard Nimoy

  8. I remember when Pioneer 10 passed Pluto and Neptune’s orbits, TRW had a telephone number set up (probably 1-900) where one could call and listen to a brief presentation along with telemtry(?) sounds.  (Our friend who worked for TRW joked, “wait till you get your next long-distance bill!”)

    Soon afterwards, Not Necessarily the News had Pioneer 10 footage with a voiceover, “Hullo, this is Pioneer 10, I’m out of the solar system right now, so please leave a message…”

  9. Can we hurry up and resume work on manned spacecraft before it comes back all sentient-like and we have to spend half a movie trying to get to it?

  10. My theory is that it will crash against the crystal sphere encasing our solar system and protecting us from the outer space phlogistron.
    That or a Mind Flayer spelljammer will enslave it. 

  11. Yeah the galactic police are going to fine Earth for littering, for throwing a tin can away randomly rather than re-cycling it like good little Earthlings…

    Or in 100,000,000 years we start a war with some other civilization by hitting their ship, space station, colony, with a physical projectile oddly engraved with our likeness and where we live. That is kind of like spitting in someones eye while staring right at them… Only consolation being that either we will all be dead and extinct by that time or advanced enough to kick their ass or asended to some sort of incorporeal godlike state… whatever comes first.

  12. Whenever I read news or commentary about the presidential election I wish I were leaving the solar system too.

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