Research claims: Voyager 1 left solar system, sudden changes in cosmic rays indicate

Mar 20, 2013
Artist concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech

Thirty-five years after its launch, Voyager 1 appears to have travelled beyond the influence of the Sun and exited the heliosphere, according to a new study appearing online today.

UPDATE: NASA denies report that Voyager left solar system

The heliosphere is a region of space dominated by the Sun and its wind of , and which is thought to be enclosed, bubble-like, in the surrounding interstellar medium of gas and dust that pervades the .

On August 25, 2012, NASA's measured drastic changes in radiation levels, more than 11 billion miles from the Sun. Anomalous cosmic rays, which are cosmic rays trapped in the outer heliosphere, all but vanished, dropping to less than 1 percent of previous amounts. At the same time, – cosmic radiation from outside of the solar system – spiked to levels not seen since Voyager's launch, with intensities as much as twice previous levels.

The findings have been accepted for publication in Geophysical Research Letters, a journal of the .

"Within just a few days, the heliospheric intensity of trapped radiation decreased, and the cosmic ray intensity went up as you would expect if it exited the heliosphere," said Bill Webber, professor emeritus of astronomy at New Mexico State University in Las Cruces. He calls this transition boundary the "heliocliff."

In the GRL article, the authors state: "It appears that [Voyager 1] has exited the main solar modulation region, revealing [hydrogen] and [helium] spectra characteristic of those to be expected in the local interstellar medium."

However, Webber notes, scientists are continuing to debate whether Voyager 1 has reached interstellar space or entered a separate, undefined region beyond the solar system.

"It's outside the normal heliosphere, I would say that," Webber said. "We're in a new region. And everything we're measuring is different and exciting."

Explore further: Lichens can survive space conditions for extended periods

More information: "Recent Voyager 1 Data Indicate that on August 25, 2012 at a Distance of 121.7 AU From the Sun, Sudden and Unprecedented Intensity Changes were Observed in Anomalous and Galactic Cosmic Rays" onlinelibrary.wiley.com/doi/10… 2/grl.50383/abstract

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User comments : 13

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baudrunner
4.2 / 5 (9) Mar 20, 2013
I'm surprised that we are still able to receive transmissions from Voyager.
Q-Star
4.3 / 5 (12) Mar 20, 2013
I'm surprised that we are still able to receive transmissions from Voyager.


I don't there is anyone who is not pleasantly surprised at the longevity of Voyager's usefulness. It's too bad that all of the space-based tools don't produce for even half as long.
antialias_physorg
4.4 / 5 (14) Mar 20, 2013
I guess the most surprising is that we can still get their signals at this distance - seeing as the signal power is a measly 23 watts.
(And the amount picked up by the 100m dish is a fraction of a billionth of a watt (!))
brt
3.7 / 5 (6) Mar 20, 2013
That's one of the great mysteries of space, why satellites in earth orbit fail while they are in the vacuum of space. The current belief is that solar activity destroys the electronics.
Lurker2358
4 / 5 (6) Mar 20, 2013
That's one of the great mysteries of space, why satellites in earth orbit fail while they are in the vacuum of space. The current belief is that solar activity destroys the electronics.


The deep space probes run in their lowest energy state so that there is very little entropy and very little loss of power.

Also, they are much farther away from massive objects, so that they experience no tidal forces and no gravitational friction.

Satellites have all their systems running full power. Communications satellites are running all their computers and processing all these signals continually. Spy and weather satellites do the same, but have cameras running all the time, so there's much more energy involved and much more components to break down.

And yeah, proximity to the Sun makes sense too.

Anyway, the more complicated something is the faster it should break.

The more energetic it is, the faster it should break.
antialias_physorg
3.9 / 5 (7) Mar 20, 2013
That's one of the great mysteries of space, why satellites in earth orbit fail while they are in the vacuum of space.


Earth orbit is actually much worse than deep space. In Earth orbit sattelites are exposed to high temperature differentials (the side towards the sun as opposed to the side pointing away from it). Heat/cool electronics a few thousand cycles like that and no wonder they crack eventually.

On the other hand in deep space everything is uniformely frosty...and the only thing you have to worry about is radiation damage.
Shootist
3 / 5 (4) Mar 20, 2013
I'm surprised that we are still able to receive transmissions from Voyager.


Plutonium is a wonderful fuel.
The Singularity
1 / 5 (2) Mar 20, 2013
Im amazed that we can still communicate with such a distant probe.

Plutonium is also a threat to our very existence.
Lurker2358
3 / 5 (6) Mar 20, 2013
Plutonium is also a threat to our very existence.


So are fire, gasoline, and kitchen knives.
HannesAlfven
1 / 5 (6) Mar 20, 2013
Things could get really interesting if the probe slams into one of these interstellar filaments which Gerrit Verschuur has written so many papers about. We could see some highly dynamic magnetic fields associated with them ...
cantdrive85
1 / 5 (6) Mar 20, 2013
That's one of the great mysteries of space, why satellites in earth orbit fail while they are in the vacuum of space. The current belief is that solar activity destroys the electronics.

Space is not a vacuum, it is teeming with moving charged particles (electric currents) that can cause interference with the electronics. Another example of the effects of the currents is the space tether experiment.

In addition, the data returned by Voyager seems to confirm the Electric Star model on the Sun.
http://electric-c...2012.pdf

katesisco
2 / 5 (4) Mar 21, 2013
Can this information be interpreted as Sol's system being closed not open?
katesisco
2 / 5 (4) Mar 21, 2013
3/20/2013 NASA says no evidence of magnetic change needed to declare.
http://phys.org/n...tml#nwlt