Study solves mysteries of Voyager 1's journey into interstellar space

October 28, 2015
Upon exiting the heliopause, the local measurements of the magnetic field by Voyager 1, shown here as a compass needle, differed by 40 degrees from the "true magnetic north" estimated to be the direction of the magnetic field in the pristine interstellar medium. As the spacecraft pushed into interstellar space, the compass needle moved ever closer to true magnetic north. Image by Kristi Donahue, UNH-EOS.

In a study published today in the Astrophysical Journal Letters, scientists from the University of New Hampshire and colleagues answer the question of why NASA's Voyager 1, when it became the first probe to enter interstellar space in mid-2012, observed a magnetic field that was inconsistent with that derived from other spacecraft observations.

Voyager 1 sent back several different indications that it had punched through the edge of our sun's massive protective bubble inflated by solar wind—the heliosphere—after a 35-year journey. But the magnetic field data gathered by the spacecraft was not what scientists had expected to see. The UNH-led study resolves the inconsistencies.

"There are still naysayers out there regarding Voyager 1 crossing through the heliopause—the edge of the heliosphere," says astrophysicist Nathan Schwadron of the UNH Institute for the Study of Earth, Oceans, and Space and department of physics and lead author of the paper. "And the reason for this doubt is that when the spacecraft supposedly broke through the heliopause we should have seen some sort of distinctive shift in the magnetic field from one medium to the other," Schwadron says.

Adding to the mystery, researchers found that the magnetic field direction observed in local interstellar space deviated by an angle of more than 40 degrees from what was expected. Some scientists posited that this deviation was an indication of Voyager 1 still being embedded in the solar wind inside the heliopause.

Schwadron and colleagues solved the discrepancies using triangulation of four different datasets gathered by other spacecraft, including the Interstellar Boundary Explorer (IBEX) mission that in 2009 discovered a mysterious "ribbon" of energy and particles believed to be associated with the .

The scientists discovered that Voyager 1—like an orienteer through the outer solar system—measures the magnetic field moving the needle on a compass with cardinal directions provided by the IBEX ribbon. The ribbon center is the direction of "true magnetic north" for the pristine interstellar magnetic field.

The study shows that the initial direction of the magnetic field observed by Voyager 1 is deflected by the heliopause, like an elastic cord wrapped around a beach ball. Therefore, the spacecraft is moving through a special region of space where magnetic fields are rotated away from true magnetic north. This means that while Voyager 1 did cross the heliopause in 2012, it is still traveling through this "muddied" magnetic field region and won't reach the "pristine" region of interstellar space until at least 2025.

Notes Schwadron, who serves as the lead scientist for the IBEX Science Operations Center at UNH, "Our analysis confirms two things for the first time: that the center of the IBEX ribbon is the direction of the interstellar and, secondly, that Voyager 1 is now beyond the heliopause."

With the recent discovery, scientists now know they'll need to wait at least another decade before Voyager enters the region of that is beyond the reach of the sun. Since the dawn of the space age, humankind has never passed through and explored this far-flung, pristine environment.

"What's the nature of the galactic environment in terms of cosmic rays and magnetic fields?" Schwadron says. "We are beginning to paint a picture of what our local interstellar environment is really like and we can tie that to what's happening in a much broader environment within the galaxy. When Voyager 1 crosses that next boundary we will be poised to probe many longstanding mysteries."

Explore further: John Richardson and John Belcher on Voyager 1's crossing and interstellar exploration

More information: Astrophysical Journal Letters, "Triangulation of the Interstellar Magnetic Field," (2015). iopscience.iop.org/article/10. … /2041-8205/813/1/L20

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21 comments

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Going
5 / 5 (1) Oct 28, 2015
Will Voyager I still be viable in 2025?
TechnoCreed
5 / 5 (6) Oct 28, 2015
Will Voyager I still be viable in 2025?

http://voyager.jp...ife.html
plasmasrevenge
1.7 / 5 (6) Oct 28, 2015
Is this the "new physics" which the IBEX team has demanded that theorists consider? Doesn't sound like new physics to me ...
Bob Osaka
5 / 5 (1) Oct 28, 2015
It is unfortunate that Voyager I is the single source of data. If we had our priorities straight we could have 360 Voyagers out there at every degree along the plane of the solar system 2/3 of which would be traveling slower without the gravity assist of Saturn and Jupiter.
The right hand rule, Biot-Savart law uses 4π as a denominator, magnetic field line for typical geometries. Maxwell's correction term for displacement current may apply.
Q, the vector of r squared or cubed, the vector of v and the vector of B for the permeability of free space as μ nought.
It is as difficult as calculating the geometry of a candle flame blowing in the wind without knowing which direction or with what intensity the wind is blowing.
The article boasts the problem solved. Rather it is one solution still open to consensus. If only we had another 358 Voyagers flying through the heliopause...
Whydening Gyre
2.3 / 5 (3) Oct 28, 2015
Oops
Whydening Gyre
3.7 / 5 (9) Oct 28, 2015
Is this the "new physics" which the IBEX team has demanded that theorists consider? Doesn't sound like new physics to me ...

STFU.
Listen a little.
Learn a little...
plasmasrevenge
2.3 / 5 (9) Oct 29, 2015
Let me help you, because you seem to be the one that is not listening ...

"but even when we put that magnetic field into our models and our theories, it doesn't produce this bright ENA ribbon."

"The ribbon is very narrow. It has a lot of fine structure in it, meaning that somehow the particles are all confined in very, very localized regions. We have NO idea how that can happen."

"So, still we're missing some really fundamental aspect of the interaction, some fundamental physics that's missing from our understanding."

"You look at it, and you go, 'No, that cannot be right.'"

These are all direct quotes from the IBEX team from 2009 which anybody can of course watch at https://www.youtu...adA6HXk.

As usual, it appears that the scientific community has decided to completely ignore the IBEX team's call to seek out some new fundamental physics. I'm not sure that the scientific community is capable at this point of properly rising to this challenge.
vlaaing peerd
not rated yet Oct 29, 2015
This might be a bit simplistic, but can't we send a probe upward from our solar system's plane instead of sending it all the way through?

I'd imagine the journey would be a whole lot shorter. Considering someone must have thought about this before, I'm obviously missing a few reasons why this is not possible.
antialias_physorg
5 / 5 (7) Oct 29, 2015
This might be a bit simplistic, but can't we send a probe upward from our solar system's plane instead of sending it all the way through?

We could (e.g. via swing by of Jupiter), but why would we want to? All the interesting stuff is in plane. Probes - especially these long range ones - are rather expensive. So it makes sense to make them multi-purpose (i.e. by having them fly by several celestial bodies and taking measurements).

Maximize science with minimal expense.
Going
5 / 5 (1) Oct 29, 2015
I see gyro operations are due to cease next year and this will make it impossible to calibrate the magnetometer. So we may never know.
vlaaing peerd
not rated yet Oct 29, 2015

We could (e.g. via swing by of Jupiter), but why would we want to?


I entirely agree with you on the usefulness of having a good look around before going interstellar. I am however mostly interested if this would provide a shorter way out.

e.g. is the heliosphere's shape a ball around the sun or is it a semi flat disk following the systems' plane?
bschott
2.6 / 5 (5) Oct 29, 2015
"You look at it, and you go, 'No, that cannot be right.'"


That phrase should be the slogan for current theoretical astrophysics because of how often it shows up when they have to talk about what they find vs. what they expect.

As usual, it appears that the scientific community has decided to completely ignore the IBEX team's call to seek out some new fundamental physics.


I believe they mean - recognize the proper fundamental physics -

"The ribbon is very narrow. It has a lot of fine structure in it, meaning that somehow the particles are all confined in very, very localized regions. We have NO idea how that can happen."


How does a physicist not understand how to confine/influence charged particles? It happens the same way EVERY TIME.
vlaaing peerd
5 / 5 (2) Oct 29, 2015

e.g. is the heliosphere's shape a ball around the sun or is it a semi flat disk following the systems' plane?


Never mind, I just found out the shortest way out is in the sun's direction within the galaxy.
antigoracle
5 / 5 (1) Oct 29, 2015
Hopefully, Voyager II will solve rather than add to the questions.
valandrade
not rated yet Oct 29, 2015
great, i'm satisfied
EnsignFlandry
5 / 5 (1) Oct 29, 2015
We should send another mission to and past the heliopause. This should have an ion-drive engine so it could build up some speed, and a stronger radio and nuclear power source. Of course it would cost money. We waste plenty on stupid stuff.
Whydening Gyre
4 / 5 (4) Oct 30, 2015
This might be a bit simplistic, but can't we send a probe upward from our solar system's plane instead of sending it all the way through?

I'd imagine the journey would be a whole lot shorter. Considering someone must have thought about this before, I'm obviously missing a few reasons why this is not possible.

Any long range probes would likely require planetary gravity assistance to achieve the speed necessary to leave the solar system, wouldn't they?
To send a probe straight "north" would probably require an enormous amount of fuel, ion drive or not, don't you think?
cantdrive85
1.8 / 5 (5) Oct 30, 2015
Study solves mysteries of Voyager 1's journey into interstellar space


Until 2025 when they fail to reach the "pristine" magnetic fields they expect. It's comical how truly ignorant these astrophysicists are of EM theory.
Captain Stumpy
4.4 / 5 (7) Oct 31, 2015
It's comical how truly ignorant these astrophysicists are of EM theory
@cd
really?
and you have some stellar record of accuracy? need i remind you about this?
http://phys.org/n...oon.html

http://phys.org/n...oon.html

http://phys.org/n...ume.html

http://phys.org/n...day.html

http://phys.org/n...ggs.html

You made some "predictions" that fail, and you make claims that are completely debunked...

but your claim is that it is all the rest of the educated astrophysicists?
perhaps you should learn why you are wrong before making grandiose claims like that?
http://ocw.mit.ed...ophysics

it's free
Hyperfuzzy
5 / 5 (1) Nov 02, 2015
Would we not require a 3 vectors, i.e. three orthogonal directions with correction for relative speed in order to define the magnetic field? The magnetic field is only due to the curl of the E field. With proper measurement we should be able to define a superimposed motion of charge centers. Their are multiple sources. The galaxy will have a field as well as the sun. How do we differentiate? The sun would obfuscate the galaxy field.
vlaaing peerd
not rated yet Nov 06, 2015
This might be a bit simplistic, but can't we send a probe upward from our solar system's plane instead of sending it all the way through?

I'd imagine the journey would be a whole lot shorter. Considering someone must have thought about this before, I'm obviously missing a few reasons why this is not possible.

Any long range probes would likely require planetary gravity assistance to achieve the speed necessary to leave the solar system, wouldn't they?
To send a probe straight "north" would probably require an enormous amount of fuel, ion drive or not, don't you think?


Straight "north" can also be done per slingshot along Jupiter.

I made the false assumption that the solar plane's flat disk was also the border with interstellar space, but it isn't, so going "north" is not a shorter route.

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