Voyager 1 encounters new region in deep space, NASA says

Dec 03, 2012
This still image and set of animations show NASA's Voyager 1 spacecraft exploring a new region in our solar system called the "magnetic highway." In this region, the sun's magnetic field lines are connected to interstellar magnetic field lines, allowing particles from inside the heliosphere to zip away and particles from interstellar space to zoom in. Credit: NASA/JPL-Caltech

(Phys.org)—NASA's Voyager 1 spacecraft has entered a new region at the far reaches of our solar system that scientists feel is the final area the spacecraft has to cross before reaching interstellar space.

Scientists refer to this new region as a magnetic highway for charged particles because our sun's magnetic field lines are connected to interstellar magnetic field lines. This connection allows lower-energy charged particles that originate from inside our heliosphere—or the bubble of charged particles the sun blows around itself—to zoom out and allows higher- from outside to stream in. Before entering this region, the charged particles bounced around in all directions, as if trapped on local roads inside the heliosphere.

The team infers this region is still inside our solar bubble because the direction of the magnetic field lines has not changed. The direction of these magnetic field lines is predicted to change when Voyager breaks through to interstellar space. The new results were described at the American Geophysical Union meeting in San Francisco on Monday.

"Although Voyager 1 still is inside the sun's environment, we now can taste what it's like on the outside because the particles are zipping in and out on this magnetic highway," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "We believe this is the last leg of our journey to interstellar space. Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."

This animated graphic shows the jumps and dips in two key populations of charged particles as NASA's Voyager 1 moved into and out of a new region called the "magnetic highway." The top graph (magenta) shows the prevalence of lower-energy charged particles that originate inside the heliosphere, which is the bubble of charged particles surrounding our sun. The bottom graph (blue) shows the prevalence of cosmic rays, which are higher-energy charged particles that originate from interstellar space. These data were obtained by Voyager 1's cosmic ray instrument. Scientists refer to this new region as a "magnetic highway" because here the sun's magnetic field lines are connected to the interstellar magnetic field lines. This connection allows low energy particles from inside the heliosphere to zip away. It also allows cosmic ray particles from interstellar space to zoom in. The populations of these particles began to change rapidly on July 28, 2012, when Voyager first entered this magnetic highway. Over the next few weeks, the new region lapped and receded from Voyager 1 like an ocean tide. The second step of the animation shows the profound dip in the inside particles and bump in outside particles in the magnetic highway region, with the crossing marked with a solid vertical line. The new region receded outward from Voyager within five days, as evidenced in the jump in inside particles and dip in outside particles (third step of the animation). The dashed line indicates when Voyager left the magnetic highway. By Aug. 13, Voyager 1 had re-entered the highway region, as shown in the fourth step of the animation. But, as shown in the fifth step, Voyager 1 left the region again on Aug. 20. In the sixth step of the animation, the graphic shows how Voyager 1 entered the new region for good on Aug. 25. Since then, the low-energy particles from inside have nearly vanished and the population of cosmic rays from outside has stabilized. Credit: NASA/JPL-Caltech/GSFC

Since December 2004, when Voyager 1 crossed a point in space called the termination shock, the spacecraft has been exploring the heliosphere's outer layer, called the heliosheath. In this region, the stream of charged particles from the sun, known as the solar wind, abruptly slowed down from supersonic speeds and became turbulent. Voyager 1's environment was consistent for about five and a half years. The spacecraft then detected that the outward speed of the solar wind slowed to zero.

The intensity of the magnetic field also began to increase at that time.

Voyager data from two onboard instruments that measure showed the spacecraft first entered this magnetic highway region on July 28, 2012. The region ebbed away and flowed toward Voyager 1 several times. The spacecraft entered the region again Aug. 25 and the environment has been stable since.

This artist's concept shows plasma flows around NASA's Voyager 1 spacecraft as it gets close to entering interstellar space. Voyager 1's Low-Energy Charged Particle instrument detects the speed of the wind of plasma, or hot ionized gas, streaming off the sun. It detected the slowing of this wind – also known as the solar wind – to zero outward velocity in a region called the stagnation region. Scientists had expected that the solar wind would turn the corner as it felt the pressure of the interstellar magnetic field and the interstellar wind flow. But that did not happen, so scientists don’t know what to expect once Voyager actually crosses the heliopause. Voyager 1 crossed a shockwave known as the Termination Shock in 2004. At the Termination Shock, the solar wind slows down abruptly from supersonic speeds. The heliopause is the boundary between the bubble of charged particles around our sun – known as the heliosphere – and interstellar space. Its location is still a mystery. Credit: NASA/JPL-Caltech/The Johns Hopkins University Applied Physics Laboratory

"If we were judging by the charged particle data alone, I would have thought we were outside the ," said Stamatios Krimigis, principal investigator of the low-energy charged particle instrument, based at the Johns Hopkins Applied Physics Laboratory, Laurel, Md. "But we need to look at what all the instruments are telling us and only time will tell whether our interpretations about this frontier are correct."

Spacecraft data revealed the magnetic field became stronger each time Voyager entered the highway region; however, the direction of the did not change.

"We are in a magnetic region unlike any we've been in before—about 10 times more intense than before the termination shock—but the magnetic field data show no indication we're in interstellar space," said Leonard Burlaga, a Voyager magnetometer team member based at 's Goddard Space Flight Center in Greenbelt, Md. "The data turned out to be the key to pinpointing when we crossed the termination shock. And we expect these data will tell us when we first reach ."

Voyager 1 and 2 were launched 16 days apart in 1977. At least one of the spacecraft has visited Jupiter, Saturn, Uranus and Neptune. Voyager 1 is the most distant human-made object, about 11 billion miles (18 billion kilometers) away from the sun. The signal from Voyager 1 takes approximately 17 hours to travel to Earth. Voyager 2, the longest continuously operated spacecraft, is about 9 billion miles (15 billion kilometers) away from our . While Voyager 2 has seen changes similar to those seen by Voyager 1, the changes are much more gradual. Scientists do not think Voyager 2 has reached the magnetic highway.

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User comments : 16

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rubberman
3.8 / 5 (16) Dec 03, 2012
When it is only the interstellar field, the direction will change. The intensity of the coupled fields is predictable.
Voyager is simply amazing.
cantdrive85
1.6 / 5 (25) Dec 03, 2012
Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."


Actually, from a news release a couple months ago, in regards to Voyager data, it was reported; "As Voyager scientists explained in a paper published last month in Nature, the perplexing collapse of the solar wind at the edge of the heliosphere left them without a working model for the outer solar system."

EU model theorists were not perplexed by this finding, actually it was predicted. Another prediction is that there should be an electron shell, or virtual cathode, at about 18 billion kilometers from the Sun. Their model is based upon plasma discharge observed in laboratory experiments, being that in excess of 99.9% of the matter within the heliosphere is electrically charged plasma it seems a rather obvious extrapolation.

http://electric-c...2012.pdf
Infinion
3.7 / 5 (18) Dec 03, 2012
These are very groundbreaking discoveries, discoveries one would imagine would merit sending more probes out to more closely examine them. Most of the sensors on voyager have long since been shut off as the power generated by voyager's RTG drops down. It's hard not to imagine that there is activity at these regions of our system's edge that we are missing.

That's not to mention that 36 years have gone by and significant improvements in propulsion, fabrication, and sensors technology would give us a shorter, cheaper, and more insightful mission to interstellar space.
brt
3.2 / 5 (13) Dec 03, 2012
These are very groundbreaking discoveries, discoveries one would imagine would merit sending more probes out to more closely examine them. Most of the sensors on voyager have long since been shut off as the power generated by voyager's RTG drops down. It's hard not to imagine that there is activity at these regions of our system's edge that we are missing.

That's not to mention that 36 years have gone by and significant improvements in propulsion, fabrication, and sensors technology would give us a shorter, cheaper, and more insightful mission to interstellar space.

I totally agree. We could send out a small fleet of probes with technology 100,000 time more advanced for the same cost of the voyager probe. There's really no reason not to do so considering how much information we would get for the money.
ka_
3.7 / 5 (16) Dec 03, 2012
There are good reasons why we should send several probes YET, the being alternative cost of other more important projects. It will take 30 years before new probes would reach the area Voyager is in, and Voyager is still surprising us. Lets at least wait and see what happens over the next few months/years until Voyager actually leave our solar system so if new surprises hits us we know what additional sensors we should have on them!

And look no further than the forums of this site! - there are still people not believing humans place too much excess CO2 in our atmosphere, there are still people not convinced we hurt the climate - we need to monitor our own planet first! Our first worldwide CO2 monitoring satellite is scheduled for 2014 - We will likely need several as just like the games of Area 51 US/Russia showed us countries might play duck - reducing production the times the satellite will pass above to claim they pollute less than they do. And that is only CO2 - we lack so much
Lurker2358
2.8 / 5 (13) Dec 03, 2012
The Voyager team infers this region is still inside our solar bubble because the direction of the magnetic field lines has not changed. The direction of these magnetic field lines is predicted to change when Voyager breaks through to interstellar space.


What is the probability that the background fields will have the same orientation as the Sun's fields?

The intensity of the magnetic field also began to increase at that time....

..."We are in a magnetic region unlike any we've been in before—about 10 times more intense than before the termination shock—but the magnetic field data show no indication we're in interstellar space,"


Why?

I thought all field equations obeyed an inverse squared law, meaning they're supposed to get weaker the farther you get away from their origin.

I suppose if you add enough particles and they all line up the right way, it could increase the magnetic field locally, but that would seem to have little to do with the sun itself...
Lurker2358
3.2 / 5 (13) Dec 03, 2012
Nevermind, I figured it out.

The probability of the Sun's field lines being oriented the same as the background (relative to the Voyager space probe) is nearly zero, and even if it did happen, the other Voyager is moving outwards at a different angle, and it definitely would emerge into a region where the change is noticeable.
Infinion
3 / 5 (10) Dec 03, 2012
@Lurker2358

The magnetic field intensity of the sun is for sure dropping off with respect to the inverse square law.

You can also confidently assume that the 10x increase in strength isn't coming from a stellar body. The closest star to us is Alpha Centauri (~4.3 light years), which is a binary. Wikipedia says A is about 10% more massive than the Sun, with a radius 23% larger, and B is about 90% the mass of the Sun and 14% smaller. At that distance, and at those comparative sizes, there is no chance that Alpha Centauri's magnetic field intensity nor our sun's can compare with what voyager 1 is seeing at its current position. The inverse square law stands by that fact.

If it isn't stellar bodies that are causing the increase then it leaves one explanation. Wikipedia says magnetic fields are produced by moving electric charges. What we are seeing here is evidence that a significant number of charges are flowing in the same direction and producing the observed magnetic field
Infinion
3 / 5 (8) Dec 04, 2012
http://www.nasa.g...203.html

scroll down to the bottom for data on magnetic field strength and direction (latitude & longitude). There is also a graph showing the frequency of low energy charged particles compared with the changing magnetic field intensity.

Lex Talonis
1.3 / 5 (10) Dec 04, 2012
Jesus - he would not know, he's still stuck in low earth orbit.
rubberman
1.8 / 5 (6) Dec 04, 2012
"You can also confidently assume that the 10x increase in strength isn't coming from a stellar body."

It originates from all stellar bodies past and present. All of the charged particles encompassed in the solar wind of every star in the galaxy eventualy wind up in interstellar space.

"It's hard not to imagine that there is activity at these regions of our system's edge that we are missing."

For sure. And agreed on the requirement for further study. I'm not so sure about the way the suns magnetic field is modeled. It is far more complicated than radial bands of charged particles "blowing a bubble". The stagnation area at the "magnetic highway" boundary seems like the place to look for the answer to the increase in field strength without a change in the fields orientation. Almost like the charged particles "pile up" against the interstellar field which creates the outermost boundary, causing the fields to couple, generating the magnetic highway.
YSLGuru
3 / 5 (8) Dec 04, 2012
And look no further than the forums of this site! - there are still people not believing humans place too much excess CO2 in our atmosphere, there are still people not convinced we hurt the climate - we need to monitor our own planet first!


You forgot to include the part about how soo many still refuse to believe that we can fix the CO2 damage done by simply paying the carbone taxes and if we just all relocate to urban areas and live in tiny cage like areas and exist like land slaves then not only can we magically fix this probelm but we will enable the liet among us to continue living the good life.

Whats harder to understand is how seeminly logical thinking humans are still buying into the carbon scam without even asking how carbon credits that reward the elite who control it will do anything but further redistribute wealth from the many to the few.
GenteelWolf
1.5 / 5 (8) Dec 04, 2012
@YSL Guru

Just because there is a scam to screw the general people over CO2, does not mean we are not polluting our planet. Why be such an extremist? I do believe the wealthy are doing the most damage with their vast sums of burnable money. I also believe they try to pawn the blame on us, and agenda 21 is a great ploy to give fascism an even stronger foothold in America. That being said, I don't let those concepts change my belief that we as a people are altering the chemical makeup of our atmosphere. No them, us, me, or you to it. Our chemical climate is changing, according to studies done by NASA.

http://climate.na...icators/

Don't worry, the butcher's bill wont arrive for a couple more generations.
Fleetfoot
5 / 5 (3) Dec 06, 2012
The magnetic field intensity of the sun is for sure dropping off with respect to the inverse square law.


The solar field is predominantly a dipole so should fall as the inverse cube. However, given that the probe has been traveling for 3 decades, you don't expect much change from that factor in a few months.
obama_socks
1.4 / 5 (9) Dec 06, 2012
I've been considering the possibility of Voyager encountering a "maelstrom" or something similar to a cosmic whirlpool where it could be buffeted around for awhile in a circular pattern. Future data should tell us if this possible...or not.
JoeBlue
1 / 5 (8) Dec 08, 2012
Why is this extremist AGW stuff in every single thread?