Where in the Universe Is Voyager? The Surprising Showdown Over Where Our Solar System Ends

Voyager 1 entered interstellar space, and then — oops! — it didn't

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NASA

Voyager 1 and 2 have been in space for 33 years and have traveled 11.5 billion and 9.5 billion miles respectively.

Not knowing where we are makes us all a little crazy. Consider how you feel when you’re driving along a strange road without a map or a GPS. Consider how you feel when you’re on the street in a city overseas, having no idea how to get back to your hotel and you don’t speak the local language. There’s a reason people freaked out when Apple dropped Google Maps. There’s a reason airplane seatbacks have little route maps on the screen. It takes a solid sense of place, it seems, to give us a solid sense of safety.

So pity the scientists tracking the Voyager 1 spacecraft.

As most people who pay attention to these things noticed yesterday, there was a cosmic battle royal when the American Geophysical Union (AGU) issued a surprise press release about new Voyager readings with the stunning headline: “Voyager 1 has left the solar system, sudden changes in cosmic rays indicate,” making it the first human-built object to cross that remarkable threshold. But NASA, which knows a thing or two about the twin Voyager spacecraft since it built them, launched them and controls them, fired back with a press release that said, in effect: Not. The NASA release tersely quoted the venerable Ed Stone, who has been at the helm of the Voyagers since the start of the program in 1972:

“The Voyager team is aware of reports today that NASA’s Voyager 1 has left the solar system,” said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena, Calif. “It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space.”

The AGU, to its credit, responded within minutes, reissuing the same press release with details of the findings unchanged, but with a more cautious headline: “CORRECTED — Voyager 1 has entered a new region of space, sudden changes in cosmic rays indicate” [emphasis added]. So, good for the AGU: it conducted a solid study, got called for a little too much breathlessness and stepped back. “It’s a matter of interpretation,” says Peter Weiss, AGU public-information manager. “We were trying to write it in a way that people would understand, so maybe we did get a little overzealous in our headline writing.”

(MORE: Voyager 1 at the Threshold of Forever)

That led to the usual schadenfreude in certain circles, the look-who-screwed-up snickering that always comes when a lab or a government or a politician has to walk back a statement. But the fact is, in this case, nobody misspoke, nobody got it wrong. Weiss is right when he says these things are a matter of interpretation — and that’s one of the reasons they’re so bloody much fun.

This isn’t the first time we’ve tried to determine if or when one of our little machines left the solar system. TIME said we did it in 1983, and before you direct those snickers our way, the scientific community was in complete accord on the matter. That time the spacecraft was Pioneer 10, and what it had done to achieve the landmark feat was cross the orbit of Neptune. Since the elliptical orbit of Pluto (which was a planet then but is no more) at that point took it inside the orbit of Neptune, Pioneer 10 had indeed passed the last recognized toll booth to the unknown.

But here’s the thing: at the time, Pioneer 10 was just 2.8 billion miles (4.5 billion km) away, and Voyager 1 — now 11 billion miles (18 billion km) distant — has nearly quadrupled that stretch. What changed is our subjective definition of where the exit door lies.

(MORE: A Leisurely Cruise on the Good Ship Solar System)

No longer do we define the solar system the way we define the highways around Beijing — with inner, middle and outer rings, all firmly circumscribed. In the same way the sprawl and the smog of Beijing reach far outside the city limits, so too does the solar system make its presence felt beyond the orbit of its last big world, thanks to the heliosphere, a vast gale of charged particles streaming forth from the sun and extending perhaps 12 billion miles (19 billion km) in all directions. Only when the solar wind becomes so attenuated that the outward flowing particles bump up against the higher energy particles of interstellar space do we now consider the solar system at an end. When you change how you draw the map, you entirely upend the sense of where — and even then there is some confusion.

In the summer of 2012, the solar wind surrounding Voyager 1 came to a dead stop, a boundary known as the heliopause, and by some definitions that should have been it, the ship should have been out. And then, capriciously, it just started up again. NASA and the AGU agree that the end game will truly be upon us when the wind stops for good and Voyager punches through the so-called heliosheath, when outward-flowing energy drops to effectively zero and inward-flowing interstellar energy spikes. Those findings were confirmed by the study the AGU released yesterday, leading to the somewhat premature announcement.

But NASA adds another condition — one that the AGU accepts: the magnetic field that surrounds the ship will have to change direction, indicating that solar magnetism is yielding to the deeper magnetism of space. Last December, the fields began interlocking and lining up — putting Voyager on what Stone calls the magnetic highway. But the ship hasn’t taken the exit ramp to deeper space yet. “A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed,” he said in the NASA release.

Before long, on the order perhaps of months, that will happen — the scientific interpretations will line up as neatly as the magnetic fields and everyone will agree that yes, Voyager 1, first a thing of the earth, then a thing of the local solar system, has well and truly become a thing of the stars. For now, let’s abide — and even enjoy — the uncertainty. On some journeys, the best answer to the question “Where are we?” is a simple “Beats the hell out of me.”

PHOTOS: 11 Billion Miles Later, Photos From the Depths of the Solar System

99 comments
RickHunter
RickHunter

Too bad none of us will be around when V-Ger returns to look for its creator.  :-)

SjRudloff
SjRudloff

"We" can bloviate all we want, but nothing beats a metaphoric tape measure.

bristolm99
bristolm99

Great article and many, many excellent comments in the mind of this very fascinated yet admittedly novice student of space exploration, science and physics.

Having said this, one thing I found remarkable as I read through the article and comments -- and I wonder if others might agree -- is that during its amazing journey Voyager I has not run into (or been run into), and destroyed, by something.

majik
majik

 Sir Issac Newton says you are wrong !  There is no "gravity" between the stars - Newton's formula makes that very clear - but what you can measure - is the electromagnetic waves of plasma particles -  That is the "force" that connects everything !

msannie5
msannie5

Your future is implanted in your brain like movie soduim pentathol n hypnosis ask yourself try not to lie, you've implants to self destruct via your education, the words were changed

dehinstodits
dehinstodits

It ends where the Sun's pull is no longer. 

Rat_27
Rat_27

> But NASA, ... , fired back with a press release that said, in effect: Not.

Did you really need to make NASA sound like a 15-year old girl?  C'mon Jeff.



 

MarkWorrell
MarkWorrell

Just a thought of whatever intelligent life--should any be out there, must be thinking as we glide by.

cpc65
cpc65

Sign at the border: Now leaving Sol system. Please drive safely and come again. 

myemailisian
myemailisian

There ya go - putting limits on things again.... there is no end - we humans own it all.

ramesh
ramesh

good to see that there is no consensus among the scientists themselves. For sure, this will put more concern and emphasis on the science community to really verify and then come to conclusion. After all, we all are trying to understand something new, and if it will be great if there are valid consensus too !

Adam_Smith
Adam_Smith

Personally, I think the boundary of the solar system is at the edge of the sun's gravity well. That consists of all those nearest locations where if an object is placed at rest with respect to the sun it would not fall back towards the sun but eventually drift away instead. I am not an astronomer and I don't know if Voyager 1 has gotten that far yet but if it hasn't I expect it will (again) be declared to have left the solar system when it does.

TimothyRigney
TimothyRigney

Not to be a Debbie Downer, in fact I think this should be UP-lifting, but if a starship existed, it would have covered this tiny distance in less than a second.  Voyager, however, is moving at around 40,000 miles per hour, or in other words, 0 miles per hour.  STAR ship?   We've a long way to go so let's "MAKE IT SO!"
(The first trick is to figure out how to go 1/10th light speed - Arthur C. Clarke brought up an excellent point that we don't know how to go that "fast," or rather, how to travel at that appallingly-slow speed.  18,628 miles per second takes more energy than we can really generate at-present and even if we can, the *heat* generated would melt the engines - plus there's "diminishing returns" - for example more nuclear energy would require heavier shielding but then you need to push more mass - similar problems with "Bussard ramscoops," ion engines etc.  But the more we learn the closer we'll get to doing it so let's get movin!   :)

DrTom
DrTom

When will Voyager reach the point where it is more strongly under the influence of the gravity of another star rather than the Sun? That is an exact, easily calculated point, though it is probably decades from now.

antonmarq
antonmarq

Well, if Voyager follows the same tracking patterns found here on earth, it will return back to earth in a few thousand years; provided the earth is not lost in space. Give me a break, this is one of those questions that will never be answered by HUMANS.... or, if you're Captain Kirk.

andyhan80
andyhan80

What if the Voyager has a Truman show ending where it hits the limit of space and it's a canvas tarp... just sayin.

texasghost01
texasghost01

When the aliens get here from finding the voyager spacecraft...it will be too late.  The asteroid will have killed us all off already.

FloydBrookman
FloydBrookman

If they launched in 1977, that is 36 years..not 33. I did the math with my TI calculator with red LED's.

ToolsrBob
ToolsrBob

And "wrong"     Hmmm spell checker?

ToolsrBob
ToolsrBob

Oops!    I spelled Solar worng!

ToolsrBob
ToolsrBob

If we assume the solor system is like a big ball with the sun in the middle... and we know it is moving through space in a circle around the center of our galaxy then> 

1) Is it really a ball or kinda of streched out like a rain drop due to resistance from stelar space? 

2) In which direction is Voyager traveling outward from the sun in relation to the direction our solar system is moving through space?

3)  Is it possible that the edge of our solar system would be closer or further in different directions from the sun ( if there is some resistance due to movement of our solar system in space)?

These are things I think about but have no idea if they these factors exist.

Any ideas from anyone?

Thanks

Bob

RickCavaretti
RickCavaretti

quotes:

 Since the elliptical orbit of Pluto (which was a planet then but is no more) at that point took it inside the orbit of Neptune, Pioneer 10 had indeed passed the last recognized toll both to the unknown.

What changed is our subjective definition of where the exit door lies.

Both are excellent analogies.


MichaelADeBose
MichaelADeBose

NASA interpretations have to be accepted as just that. Good science doesn't require consensus. We always look back on previous centuries and what science had to endure and the same silliness continues to play itself out only the consensus seems to be that things are somehow different now. The politicization of science, the litmus test and the cool kids table in the lunchroom still exist. Despite that there are exceptional accomplishments taking place all the time. NASA shouldn't feel the need to weigh in all the time. The role they play as enablers of imagination in the minds of the young and the old is priceless as is. Even if a project is theirs and even if they were a privately funded organization, they still don't own the science. That "breathlessness" is everything that's needed and what's probably been missing around NASA for a long time. 

audaniels
audaniels

Wondering about another criterion: In its present position (or in its position when the magnetic criterion is fulfilled) , if Voyager 1 either no longer has motive power (or if it does and it were turned off) will it slowly decelerate, reach zero velocity relative to the sun, and then begin to fall back toward the Sun? If so, then the primary influence on its behavior is still our solar system.

randallmckay
randallmckay

One can imagine how lonely it would feel to be that far adrift from Earth and the life giving warmth of the Sun. Why is everything so big and small at the same time?

BobbyJams
BobbyJams

None of the stories I read so far mention how they get the  Voyager readings?  Can I assume that the Voyager is still transmitting info to earth?  If so how much longer will the Voyager be able to send and the receivers on earth be able to receive info?  At this distance, 11 Billion miles how long would it take the signal to reach the earth? (I know I could take the time to look-up the speed of light and calculate it?)  I feel this information should have been in these news stories for the general public.