Voyager 1 Is In the Stagnation Zone

… and probably has been there for months, but new research is confirming the nature of this very interesting phenomenon. It is the outer edge of our solar system, where fast moving stuff heading away from the sun has slowed down because it’s movement is stifled by gravity, but some extra-energetic particles are still leaking out into the greater galactic region, from which they are unlikely to return. Also, the solar system’s magnetic fluxy stuff is bunched up in this region.

The cool thing about this is that we don’t really know exactly what is happening. Enough is known about the solar system, the sun, magnetics, plasma and particles, and stuff to have a reasonable model of what Voyager 1 will encounter, but the details remain quite vague.

“Voyager tells us now that we’re in a stagnation region in the outermost layer of the bubble around our solar system,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “Voyager is showing that what is outside is pushing back. We shouldn’t have long to wait to find out what the space between stars is really like.”

Although Voyager 1 is about 11 billion miles (18 billion kilometers) from the sun, it is not yet in interstellar space. In the latest data, the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere, the bubble of charged particles the sun blows around itself. The data do not reveal exactly when Voyager 1 will make it past the edge of the solar atmosphere into interstellar space, but suggest it will be in a few months to a few years.

Scientists previously reported the outward speed of the solar wind had diminished to zero in April 2010, marking the start of the new region. Mission managers rolled the spacecraft several times this spring and summer to help scientists discern whether the solar wind was blowing strongly in another direction. It was not. Voyager 1 is plying the celestial seas in a region similar to Earth’s doldrums, where there is very little wind.

More details here.

Comments

  1. #1 Doug Alder
    December 6, 2011

    I found “Voyager is showing that what is outside is pushing back. ” to be interesting – is there a (reasonable) chance that the force being exerted on Voyager from outside the solar system will be strong enough to counter the momentum Voyager has and bring it to a “standstill” probably a really stupid question – I know nothing about physics

  2. #2 Greg Laden
    December 6, 2011

    I’m pretty sure not. These are forces that are very large but very weak at one spot. More like a bunch of leaves blowing back on your lawn after you’ve raked it off. It could drive you crazy but it could not push your snow blower along any distance.

  3. #3 Zippy the Pinhead
    December 6, 2011

    On a cosmic scale, 11 billion miles is less than 0.002 light years. It would take over 10000 years for Voyager to go 1 light year, one-fourth of the distance to the nearest star (even if it was heading in that direction). Voyager is barely across the lawn let alone the neighborhood.

  4. #4 StevoR
    December 10, 2011

    From what I’ve read I gather the Oort cloud of comets – the outernmost limits of the solar system – probably extends out about one to 1 & 1/2 light years from our daytime star.

    Voyager may have found the limit of the solar wind and heliosheath but its centuries even aeons from departing the solar system. A sobering thought really.

  5. #5 Greg Laden
    December 10, 2011

    Right, the outer limit of the oort cloud is said to define the outer boundary. I’ve seen it put closer than you are saying … under one light year … but that’s still farther than Voyager 1.

    Interesting, though, the cloud has not been observed or proven to exist. Someday, Voyager 1 will run into it. However, I doubt there will be enough power to send the signal back to earth. Also, at Voyager’s current rate of movement it may reach the Ooort cloud after the sun has exploded. If we play our cards right, we can pick up Voyager in one of our Star Ships on our way outta here.

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