8 ms·

After 35 years, Voyager nears edge of solar system

161 points by dirktheman 14y ago

kibwen 14y ago
Additional reading: "The heliopause is the theoretical boundary where the Sun's solar wind is stopped by the interstellar medium; where the solar wind's strength is no longer great enough to push back the stellar winds of the surrounding stars. Voyager 1 is expected to cross the heliopause by 2014. The crossing of the heliopause should be signaled by a sharp drop in the temperature of charged particles, a change in the direction of the magnetic field, and an increase in the amount of galactic cosmic rays." http://en.wikipedia.org/wiki/Heliosphere#Heliopause http://en.wikipedia.org/wiki/Heliosphere#Heliopause
- cstuder 14y ago
  And apparently the heliopause is already overdue: http://arstechnica.com/science/2012/09/missing-voyager-1-yet-to-find-the-boundary-line-of-the-solar-system/ http://arstechnica.com/science/2012/09/missing-voyager-1-yet...
gokhan 14y ago
So Stone can't say how long it will be before Voyager passes through it. "I can't tell you whether it's days, months or years. I really can't tell you," he said. I'm not complaining, but that's why we hear this story over and over again, every 3 months for the last 10 years.
- dirktheman 14y ago
  It depends on your definition of ‘edge of solar sytem’, as there are many definitions around. What amazes me the most is that we built something 35 years ago, shot it into space and it’s still going strong, sending radio signals from a place so far away that it takes 16 hours to get here. They supplied it with an 8-track disc that contains information about earth and humanity. To me, this speaks volumes about the brilliant naivety of that era, and I mean naivety in the most positive way possible: an uncurbed enthousiasm where you don’t see all the implications and problems on your path, but just execute. Did they think about the fact that 8-track records would be outdated by the time the Voyager would reach a destination where alien life would be possible? It seems not. But they built the thing, and it’s still doing what is’s supposed to do. This mindset has been missing for a long time, although the new Mars Rover project has got my hopes up again.
  - alberich 14y ago
    > What amazes me the most is that we built something 35 years ago, shot it into space and it’s still going strong, sending radio signals from a place so far away that it takes 16 hours to get here. I completely agree. I remember reading about Voyager 1 and 2 back in 1989, when I was a just a child, and thinking how cool it was that humans could build something to send into space and it could last so long. 23 years later, it is even more impressive that it is still out there and kicking... and may last another 10 years :) It is very impressive, to say the least.
    - slamdunc 14y ago
      One thing that really stuck in my mind when I heard the story was that, even 35 years later, "we're now a substantial fraction of a 'light-day' from the Earth..." With the term "light-years" most commonly mentioned (eg, from a few days ago: http://www.geek.com/articles/geek-cetera/astronomers-find-sugar-400-light-years-from-earth-2012092/ http://www.geek.com/articles/geek-cetera/astronomers-find-su... ) I think hearing about light-hours and light-days helps to put things a little more into perspective (though it's all still mind-boggling).
  - jambo 14y ago
    I agree with you that it speaks volumes about the optimism of the era. That said, Sagan & Druyan gave a great deal of thought to the "message in a bottle": http://en.wikipedia.org/wiki/Voyager_Golden_Record http://en.wikipedia.org/wiki/Voyager_Golden_Record
    - dirktheman 14y ago
      Thanks for the link! I do wonder however if an alien, should it encounter one, could figure out the symbols on the cover. The 'record player' symbol is pretty self-explanatory if you already know what a record player is, but I suspect that to an average 16-year old teenager it's complete gibberish...
      - cryptoz 14y ago
- kabdib 14y ago
  "Are we there yet?" "Are we there yet?" "Are we there yet?" :-) The fact that this old spacecraft is still sending us useful data is pretty neat, and I don't mind being reminded of it. I remember the various flybys (Jupiter, Saturn, and my local PBS station's "Neptune All Night"). In the age of consumer products that last a couple of years before they disintegrate, a 35 year old machine still operating in a hostile environment is an inspiration.
anovikov 14y ago
First time i heard that was 'Voyager was nearing edge of solar system' when i was in high school.
- Two9A 14y ago
  That's because there are many edges of the solar system. The one you probably heard about was the termination shock, where the solar wind goes subsonic. I forget how far out that is, but it's closer than the heliopause. From the graphs of radiation intensity, Voyager is either in a big bubble of interstellar space trapped in the heliopause, or actually through and out the other side. It's exciting either way.
  - danielweber 14y ago
    Query: how do you define "subsonic" in the near-vacuum of spce?
    - mrcharles 14y ago
      When you can hear it, duh.
    - jessriedel 14y ago
      As you probably know, the "speed of sound" in an arbitrary medium is just the speed at which disturbances in pressure propagate. For this to be well-defined, the particles have to collide with each other often enough for there to be collective disturbances (rather than just individual fast moving particles). I would have thought that there was so much distance between particles in interstellar space that they never collided, but apparently there are often enough collisions to define a notion of sound. Here's wikipedia: > The shock arises because solar wind particles are emitted from stars at about 400 km/s, while the speed of sound (in the interstellar medium) is about 100 km/s. (The exact speed depends on the density, which fluctuates considerably.) The interstellar medium, although very low in density, nonetheless has a constant pressure associated with it; the pressure from the solar wind decreases with the square of the distance from the star. As one moves far enough away from the star, the pressure from the interstellar medium becomes sufficient to slow the solar wind down to below its speed of sound; this causes a shock wave.
CodeCube 14y ago
Considering it's life expectancy is already about half over ... we should launch another probe or two (perhaps in the opposite direction?). We have better today these days and could probably build it to go for many decades longer. The sooner we launch, the sooner our kids will have data.
- dirktheman 14y ago
  We already did: the New Horizons is out there, too. But in the 60's and 70's there was a lot more budget than these days...
  - CodeCube 14y ago
    oh cool, hadn't seen that. Hopefully the probe will keep going after its initial mission to pluto has concluded.
- danielweber 14y ago
  One big reason for launching when they did was the conjunction of the planets that let them slingshot past so many of them. Jupiter/Saturn conjunctions happen every 20 years or so, but getting Uranus/Neptune in the mix (which Voyager 2 did, IIRC) is a lot more rare.
noinput 14y ago
> Voyager 1 can keep talking to Earth for about another decade. That's how long the plutonium that powers it should last. After it falls silent, it will still keep going. But it will be about 40,000 years before it wanders close to another star. Something about that last paragraph that brings the whole article full circle with lofty, child-like dreams. Makes me wonder if mankind will create the technology (and find a way possible) to go out into deep space and pass Voyager before that happens.
- ChuckMcM 14y ago
  I am often inspired by the Voyager program because I see it as one where the program planners did not put limits on themselves. And the fact that it would be 40,000 years before the problem came close to another star was also fascinating. And then I consider that its only been in the last decade were we've been looking at asteroids in an effort to identify potential disasters before they happen. If some alien probe went through our solar system, it is only just now that we would notice it at the size of Voyager, and then we wouldn't pay attention because if it re-entered the atmosphere it wouldn't do significant damage. Doesn't bode well for the aliens seeing it unless they are looking for it.
- ars 14y ago
  The only current candidate is http://en.wikipedia.org/wiki/New_Horizons http://en.wikipedia.org/wiki/New_Horizons but I don't think it has enough plutonium to last as long as Voyager, plus it's not as fast as Voyager and will never pass it. Voyager is so fast because it took advantage of an unusual planetary alignment.
technotony 14y ago
I love how old fashioned the images look. Even to me, 35 years on, we look like untechnologically sophisticated... what a difference the microprocessor makes!!
adrianwaj 14y ago
At least now it can hit a worm hole and the Veloxi will know Earth's inhabitable. Thanks NASA.
bbayer 14y ago
Year 2012, human kind can get signals from 35 years-old spacecraft which is passing edge of solar system. Year 2012, I can barely have signal reception with my brand new smartphone at my home.
jnazario 14y ago
actually i was just reading on the SciAm blogs about this, and learned a bit more about the edge of our solar system (and how the scientists involved in this effort are tracking progress). http://blogs.scientificamerican.com/observations/2012/09/05/nasas-voyager-1-spacecraft-may-not-be-near-edge-of-solar-system-after-all/ http://blogs.scientificamerican.com/observations/2012/09/05/... key comment: 'Decker and his colleagues conclude from the plasma measurements “that Voyager 1 is not at present close to the heliopause, at least in the form that it has been envisioned up to now.” ' just an interesting addendum to the story that NPR glossed over.
prawn 14y ago
Amazingly, still 10-20,000 years from the Oort Cloud.
brianmackey 14y ago
Am I really the only person who hears about Voyager and immediately thinks of "Star Trek: The Motion Picture"? At least reality is comporting with canon, vis-à-vis V'Ger: http://www.youtube.com/watch?v=gxAaVqdz_Vk http://www.youtube.com/watch?v=gxAaVqdz_Vk

161 points by dirktheman 14y ago

Additional reading: "The heliopause is the theoretical boundary where the Sun's solar wind is stopped by the interstellar medium; where the solar wind's strength is no longer great enough to push back the stellar winds of the surrounding stars. Voyager 1 is expected to cross the heliopause by 2014. The crossing of the heliopause should be signaled by a sharp drop in the temperature of charged particles, a change in the direction of the magnetic field, and an increase in the amount of galactic cosmic rays." http://en.wikipedia.org/wiki/Heliosphere#Heliopause http://en.wikipedia.org/wiki/Heliosphere#Heliopause

cstuder 14y ago
And apparently the heliopause is already overdue: http://arstechnica.com/science/2012/09/missing-voyager-1-yet-to-find-the-boundary-line-of-the-solar-system/ http://arstechnica.com/science/2012/09/missing-voyager-1-yet...

gokhan 14y ago

So Stone can't say how long it will be before Voyager passes through it. "I can't tell you whether it's days, months or years. I really can't tell you," he said. I'm not complaining, but that's why we hear this story over and over again, every 3 months for the last 10 years.

dirktheman 14y ago
It depends on your definition of ‘edge of solar sytem’, as there are many definitions around. What amazes me the most is that we built something 35 years ago, shot it into space and it’s still going strong, sending radio signals from a place so far away that it takes 16 hours to get here. They supplied it with an 8-track disc that contains information about earth and humanity. To me, this speaks volumes about the brilliant naivety of that era, and I mean naivety in the most positive way possible: an uncurbed enthousiasm where you don’t see all the implications and problems on your path, but just execute. Did they think about the fact that 8-track records would be outdated by the time the Voyager would reach a destination where alien life would be possible? It seems not. But they built the thing, and it’s still doing what is’s supposed to do. This mindset has been missing for a long time, although the new Mars Rover project has got my hopes up again.
- alberich 14y ago
  > What amazes me the most is that we built something 35 years ago, shot it into space and it’s still going strong, sending radio signals from a place so far away that it takes 16 hours to get here. I completely agree. I remember reading about Voyager 1 and 2 back in 1989, when I was a just a child, and thinking how cool it was that humans could build something to send into space and it could last so long. 23 years later, it is even more impressive that it is still out there and kicking... and may last another 10 years :) It is very impressive, to say the least.
  - slamdunc 14y ago
    One thing that really stuck in my mind when I heard the story was that, even 35 years later, "we're now a substantial fraction of a 'light-day' from the Earth..." With the term "light-years" most commonly mentioned (eg, from a few days ago: http://www.geek.com/articles/geek-cetera/astronomers-find-sugar-400-light-years-from-earth-2012092/ http://www.geek.com/articles/geek-cetera/astronomers-find-su... ) I think hearing about light-hours and light-days helps to put things a little more into perspective (though it's all still mind-boggling).
- jambo 14y ago
  I agree with you that it speaks volumes about the optimism of the era. That said, Sagan & Druyan gave a great deal of thought to the "message in a bottle": http://en.wikipedia.org/wiki/Voyager_Golden_Record http://en.wikipedia.org/wiki/Voyager_Golden_Record
  - dirktheman 14y ago
    Thanks for the link! I do wonder however if an alien, should it encounter one, could figure out the symbols on the cover. The 'record player' symbol is pretty self-explanatory if you already know what a record player is, but I suspect that to an average 16-year old teenager it's complete gibberish...
    - cryptoz 14y ago
kabdib 14y ago
"Are we there yet?" "Are we there yet?" "Are we there yet?" :-) The fact that this old spacecraft is still sending us useful data is pretty neat, and I don't mind being reminded of it. I remember the various flybys (Jupiter, Saturn, and my local PBS station's "Neptune All Night"). In the age of consumer products that last a couple of years before they disintegrate, a 35 year old machine still operating in a hostile environment is an inspiration.

anovikov 14y ago

First time i heard that was 'Voyager was nearing edge of solar system' when i was in high school.

Two9A 14y ago
That's because there are many edges of the solar system. The one you probably heard about was the termination shock, where the solar wind goes subsonic. I forget how far out that is, but it's closer than the heliopause. From the graphs of radiation intensity, Voyager is either in a big bubble of interstellar space trapped in the heliopause, or actually through and out the other side. It's exciting either way.
- danielweber 14y ago
  Query: how do you define "subsonic" in the near-vacuum of spce?
  - mrcharles 14y ago
    When you can hear it, duh.
  - jessriedel 14y ago
    As you probably know, the "speed of sound" in an arbitrary medium is just the speed at which disturbances in pressure propagate. For this to be well-defined, the particles have to collide with each other often enough for there to be collective disturbances (rather than just individual fast moving particles). I would have thought that there was so much distance between particles in interstellar space that they never collided, but apparently there are often enough collisions to define a notion of sound. Here's wikipedia: > The shock arises because solar wind particles are emitted from stars at about 400 km/s, while the speed of sound (in the interstellar medium) is about 100 km/s. (The exact speed depends on the density, which fluctuates considerably.) The interstellar medium, although very low in density, nonetheless has a constant pressure associated with it; the pressure from the solar wind decreases with the square of the distance from the star. As one moves far enough away from the star, the pressure from the interstellar medium becomes sufficient to slow the solar wind down to below its speed of sound; this causes a shock wave.

CodeCube 14y ago

Considering it's life expectancy is already about half over ... we should launch another probe or two (perhaps in the opposite direction?). We have better today these days and could probably build it to go for many decades longer. The sooner we launch, the sooner our kids will have data.

dirktheman 14y ago
We already did: the New Horizons is out there, too. But in the 60's and 70's there was a lot more budget than these days...
- CodeCube 14y ago
  oh cool, hadn't seen that. Hopefully the probe will keep going after its initial mission to pluto has concluded.
danielweber 14y ago
One big reason for launching when they did was the conjunction of the planets that let them slingshot past so many of them. Jupiter/Saturn conjunctions happen every 20 years or so, but getting Uranus/Neptune in the mix (which Voyager 2 did, IIRC) is a lot more rare.

noinput 14y ago

> Voyager 1 can keep talking to Earth for about another decade. That's how long the plutonium that powers it should last. After it falls silent, it will still keep going. But it will be about 40,000 years before it wanders close to another star. Something about that last paragraph that brings the whole article full circle with lofty, child-like dreams. Makes me wonder if mankind will create the technology (and find a way possible) to go out into deep space and pass Voyager before that happens.

ChuckMcM 14y ago
I am often inspired by the Voyager program because I see it as one where the program planners did not put limits on themselves. And the fact that it would be 40,000 years before the problem came close to another star was also fascinating. And then I consider that its only been in the last decade were we've been looking at asteroids in an effort to identify potential disasters before they happen. If some alien probe went through our solar system, it is only just now that we would notice it at the size of Voyager, and then we wouldn't pay attention because if it re-entered the atmosphere it wouldn't do significant damage. Doesn't bode well for the aliens seeing it unless they are looking for it.
ars 14y ago
The only current candidate is http://en.wikipedia.org/wiki/New_Horizons http://en.wikipedia.org/wiki/New_Horizons but I don't think it has enough plutonium to last as long as Voyager, plus it's not as fast as Voyager and will never pass it. Voyager is so fast because it took advantage of an unusual planetary alignment.

technotony 14y ago

I love how old fashioned the images look. Even to me, 35 years on, we look like untechnologically sophisticated... what a difference the microprocessor makes!!

adrianwaj 14y ago

At least now it can hit a worm hole and the Veloxi will know Earth's inhabitable. Thanks NASA.

bbayer 14y ago

Year 2012, human kind can get signals from 35 years-old spacecraft which is passing edge of solar system. Year 2012, I can barely have signal reception with my brand new smartphone at my home.

jnazario 14y ago

actually i was just reading on the SciAm blogs about this, and learned a bit more about the edge of our solar system (and how the scientists involved in this effort are tracking progress). http://blogs.scientificamerican.com/observations/2012/09/05/nasas-voyager-1-spacecraft-may-not-be-near-edge-of-solar-system-after-all/ http://blogs.scientificamerican.com/observations/2012/09/05/... key comment: 'Decker and his colleagues conclude from the plasma measurements “that Voyager 1 is not at present close to the heliopause, at least in the form that it has been envisioned up to now.” ' just an interesting addendum to the story that NPR glossed over.

prawn 14y ago

Amazingly, still 10-20,000 years from the Oort Cloud.

brianmackey 14y ago

Am I really the only person who hears about Voyager and immediately thinks of "Star Trek: The Motion Picture"? At least reality is comporting with canon, vis-à-vis V'Ger: http://www.youtube.com/watch?v=gxAaVqdz_Vk http://www.youtube.com/watch?v=gxAaVqdz_Vk