After 35 years, Voyager nears edge of solar system(npr.org)
npr.org
After 35 years, Voyager nears edge of solar system
http://www.npr.org/2012/09/05/160609488/after-35-years-voyager-nears-edge-of-solar-system
11 comments
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 Did they think about the fact that 8-track records would be outdated by the time the Voyager would reach a destination where alien life would be possible?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.
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 Did they think about the fact that 8-track records would be outdated by the time the Voyager would reach a destination where alien life would be possible?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.
> 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.
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.
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-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).
With the term "light-years" most commonly mentioned (eg, from a few days ago: 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).
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
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...
> to an average 16-year old teenager it's complete gibberish...
But an average 16 year old teenager isn't going to be the one to find the record floating in space. Rather, by definition, if the record is found, it will be found by an extremely advanced spacefaring civilization. Hopefully, they can decode it.
But an average 16 year old teenager isn't going to be the one to find the record floating in space. Rather, by definition, if the record is found, it will be found by an extremely advanced spacefaring civilization. Hopefully, they can decode it.
I was listening to CBC radio's Quirk and Quarks the other night (last night perhaps?) and on the show they were discussing the possibility of life in the universe.
People seem to hope that there are super advanced extraterrestrial civilizations, or just one maybe, out there somewhere a billion of years old. Someone to catch Voyager and look at the gold record of greetings from Earth.
The astrophysicist guest on the radio program described how the universe began, what elements existed when, more complex later on. It took a very long time for the early Universe to cool, a long time for it to condense, a long time for suns to exist which created elements, cycle after cycle of suns born and then die, then a long time for heavier complex elements to form. Then perhaps planets, any planets but maybe only a few that could support life. A long time.
Pretty much what he was saying was all life had the same amount of time to develop because the elements to create planets, molecules, life etc. didn't exist yet and when they did it exist it was at the same time everywhere, more or less.
There probably isn't a billion year old civilization out there since it couldn't come into existence there weren't any elements to make it and no way for any short cuts.
I think this is it, it's audio only: http://www.cbc.ca/quirks/episode/2010/01/02/the-top-10-unans...
People seem to hope that there are super advanced extraterrestrial civilizations, or just one maybe, out there somewhere a billion of years old. Someone to catch Voyager and look at the gold record of greetings from Earth.
The astrophysicist guest on the radio program described how the universe began, what elements existed when, more complex later on. It took a very long time for the early Universe to cool, a long time for it to condense, a long time for suns to exist which created elements, cycle after cycle of suns born and then die, then a long time for heavier complex elements to form. Then perhaps planets, any planets but maybe only a few that could support life. A long time.
Pretty much what he was saying was all life had the same amount of time to develop because the elements to create planets, molecules, life etc. didn't exist yet and when they did it exist it was at the same time everywhere, more or less.
There probably isn't a billion year old civilization out there since it couldn't come into existence there weren't any elements to make it and no way for any short cuts.
I think this is it, it's audio only: http://www.cbc.ca/quirks/episode/2010/01/02/the-top-10-unans...
Or probably there is.
Because we make some assumptions about what and how life should be. The question 'what is life?' is itself is unanswered. There fore to imagine earth like planets with earth like intelligent humans is sort of a wrong assumption to start with. As per Stephen Hawking, there might be life in stars too! A kind of life which we don't understand. They might argue, earth like planets to be too cold to survive or water to be dangerous to life.
What we know so far is a lot, but even that lot- is more or less like a drop of water in all oceans in the world.
Sometimes people unsuccessfully try to solve problems the traditional way. But somebody comes along and totally changes the paradigm of thought and presents solutions to problem in ways and directions unimaginable before. Those solutions look like a 'bolt from the blue' taking people totally by surprise. Like how Marian Rejewski surprised everybody else by cracking the German Enigma cipher. Such solutions are likely to give us deep insights in the future.
But for the moment 'impossible' should be banned word for stuff like this.
Because we make some assumptions about what and how life should be. The question 'what is life?' is itself is unanswered. There fore to imagine earth like planets with earth like intelligent humans is sort of a wrong assumption to start with. As per Stephen Hawking, there might be life in stars too! A kind of life which we don't understand. They might argue, earth like planets to be too cold to survive or water to be dangerous to life.
What we know so far is a lot, but even that lot- is more or less like a drop of water in all oceans in the world.
Sometimes people unsuccessfully try to solve problems the traditional way. But somebody comes along and totally changes the paradigm of thought and presents solutions to problem in ways and directions unimaginable before. Those solutions look like a 'bolt from the blue' taking people totally by surprise. Like how Marian Rejewski surprised everybody else by cracking the German Enigma cipher. Such solutions are likely to give us deep insights in the future.
But for the moment 'impossible' should be banned word for stuff like this.
Totally agree. Even our assumptions on the concept of time are debatable. Sure, we could say the our planet is n years old, but we assume time is something linear, inflexible. When it comes to the unknown, we can't say some things are impossible. And kudos for the Marjan Rejewski reference! I'm into cryptography lately, and it's (another) amazing story.
To be fair to the person I was paraphrasing was responding to a specific question about intelligent life.
> Hopefully, they can decode it.
There is a fair amount of debate regarding whether or not this would actually be a good thing, for example Stephen Hawking doesn't think so: http://news.bbc.co.uk/2/hi/uk_news/8642558.stm
There is a fair amount of debate regarding whether or not this would actually be a good thing, for example Stephen Hawking doesn't think so: http://news.bbc.co.uk/2/hi/uk_news/8642558.stm
The notion that we shouldn't try to contact aliens for fear they might destroy us is a silly one. I would rather be destroyed by an alien race versus being destroyed by any number of natural disaster or nuclear war.
There's also a good chance that by the time a race can travel between interstellar space, they'll be mature enough not to kill everything they see.
There's also a good chance that by the time a race can travel between interstellar space, they'll be mature enough not to kill everything they see.
> There's also a good chance that by the time a race can travel between interstellar space, they'll be mature enough not to kill everything they see.
What makes you think that? Humans just put 1 ton hover over another planet yet we still kill each other over which parts of which iron age books we think are more than just stories.
What we do know is that within a populous of a given scientific advancement its possible for there to be a massive variation of individual and group morality as well as individual education level (particularly in regards to science). We know this because it's our current world.
Based on the reality we know about it isn't terribly apparent to me that just because some population has achieved a given level of scientific advancement that some of them won't gleefully steal my lunch.
What makes you think that? Humans just put 1 ton hover over another planet yet we still kill each other over which parts of which iron age books we think are more than just stories.
What we do know is that within a populous of a given scientific advancement its possible for there to be a massive variation of individual and group morality as well as individual education level (particularly in regards to science). We know this because it's our current world.
Based on the reality we know about it isn't terribly apparent to me that just because some population has achieved a given level of scientific advancement that some of them won't gleefully steal my lunch.
I don't really see the drawbacks in contacting them. I am sure any specie that is able to travel to Earth will already have the technological means to scout a large part of (if not the whole) galaxy, and would have most likely found us in the first place.
I agree, within the human race, enormous variations in intelligence, opinion, morality, development et al exist. But there is a good chance that aliens, if they exist, don't think or behave like humans. Maybe they are some Borg-like people with a collective mind. Anyway, I'm pretty sure that IF they exist, they leave humanity alone. With the mess we're making, they'd steer clear from the depraved, self-destructing human race. Can't blame them...
I would rather not be destroyed at all.
Competitiveness has been the driver of all human progress. Without it people just stagnate.
So any interstellar race is likely to be very competitive. You hope it doesn't show up as killing, but the reality is when you have two people who both want something, they fight.
So any interstellar race is likely to be very competitive. You hope it doesn't show up as killing, but the reality is when you have two people who both want something, they fight.
I can't remember where I heard this theory, but essentially it goes like this:
If you see an ant on the sidewalk when you're walking down the street, you don't stop to communicate with it, or teach it how to build a television. The theory goes that a civilization with the ability to travel through interstellar space would have a similar knowledge gap to us as we do to ants.
Granted, you also don't stop to ask it if you can build a house on top of its ant hill, so I suppose the analogy works both ways.
If you see an ant on the sidewalk when you're walking down the street, you don't stop to communicate with it, or teach it how to build a television. The theory goes that a civilization with the ability to travel through interstellar space would have a similar knowledge gap to us as we do to ants.
Granted, you also don't stop to ask it if you can build a house on top of its ant hill, so I suppose the analogy works both ways.
But if ants could and did paint little ant-paintings and murals, I bet someone would be collecting said paintings. Also, some website would have people arguing about the nuances of them. If aliens are to us as we are to ants, they might not need to care much about us to spawn a few instances of their minds and cross interstellar distances so as to chat with us as much as we care to. It might be so little effort for them so as not to need much reward. Just as kids have ant-farms.
I think the knowledge gap between humans and ants is less then humans/ alien species that traveled to earth. Hawking is right and we should avoid making contact with any alien species...Security through obscurity actually works well in this situation.
This is a pretty naive view of the universe. Humans have been civilized as we know it for what, 4000, 5000 years? In a little over 100 years we've gone from horse-and-buggy to detecting dark matter and building particle accelerators.
The universe operates on a time scale incredibly more significant than that, and so it's conceivable that there are intelligent beings that have been around for millions of years. Their technology and the form that they take would likely be so far beyond what we know that a similar gap in evolution would be entirely plausible.
The universe operates on a time scale incredibly more significant than that, and so it's conceivable that there are intelligent beings that have been around for millions of years. Their technology and the form that they take would likely be so far beyond what we know that a similar gap in evolution would be entirely plausible.
That is true, but the analogy stops as we are very familiar with ants. On the other hand, a totally new specy of insect would be worth being studied, and thus preserved - at least partially.
"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.
"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.
> 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.
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.
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.
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.
The only current candidate is 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.
Voyager is so fast because it took advantage of an unusual planetary alignment.
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
"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
And apparently the heliopause is already overdue: http://arstechnica.com/science/2012/09/missing-voyager-1-yet...
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.
Year 2012, I can barely have signal reception with my brand new smartphone at my home.
First time i heard that was 'Voyager was nearing edge of solar system' when i was in high school.
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.
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.
Query: how do you define "subsonic" in the near-vacuum of spce?
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.
> 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.
Just curious why the speed of sound in interstellar medium depends on density, while in the Earth atmosphere, it does not (it is nearly same as on surface, around 10% smaller, on 100,000ft where there is hardly 2% of surface air pressure).
When you can hear it, duh.
Could it be that definition of edge of the solar system would change in such a way that Voyager would always be nearing its border?
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.
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.
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...
oh cool, hadn't seen that. Hopefully the probe will keep going after its initial mission to pluto has concluded.
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
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/...
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.
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.
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!!
Amazingly, still 10-20,000 years from the Oort Cloud.
At least now it can hit a worm hole and the Veloxi will know Earth's inhabitable. Thanks NASA.
"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.