Voyager 1 Officially Exits Our Solar System 237
An anonymous reader writes "A new study released today (abstract) indicates that the Voyager 1 spacecraft has become the first man-made object to exit our solar system. Instrumentation data sent back to NASA indicate the historic event likely occurred on August 25, 2012, evidenced by drastic changes in radiation levels as the craft ventured past the heliopause. What remains to be seen, however, is whether Voyager 1 has actually made it to true interstellar space, or whether it has entered a separate, undefined region beyond our solar system. Either way, the achievement is truly monumental. 'It's outside the normal heliosphere, I would say that. We're in a new region,' said Bill Webber, professor emeritus of astronomy at New Mexico State University in Las Cruces. 'And everything we're measuring is different and exciting.'"
Update: 03/20 20:44 GMT by S : Reader skade88 points out that the JPL Voyager team is not so sure: "It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called 'the magnetic highway' where energetic particles changed dramatically. 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." So we'll probably be hearing about this again in a couple years.
Hard to define (Score:5, Funny)
I would say that "true interstellar space" was "outside the gravitational effect of our sun" but, technically, that's nowhere in the universe.
Re:Hard to define (Score:5, Informative)
The edge of the solar system is considered by many to be the Oort cloud. That's about 1 light year from the Sun, and Voyager is not even remotely close.
Re:Hard to define (Score:5, Informative)
Though:
Voyager 1 is in the process of escaping the solar system at a speed of about 523.6 million km per year, or about 1.4 million km per day. Even at this tremendous speed, Voyager 1 will take at least 14,000 years (and maybe twice that or even longer) to emerge from the Oort cloud. http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Voyager_1&Target=Beyond [nasa.gov]
Re:Hard to define (Score:5, Insightful)
I think the interesting question is, what would constitute evidence of the Oort cloud's actual existence? Every textbook and Wikipedia article I've read still describes it as a theoretical construct.
But yeah, it took us 40 years to get out to 130 AU, and astronomer's talk about comet dust being out as far as 50,000 AU. A humbling thought to be sure.
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I realize it would still take way beyond my life
Re:Hard to define (Score:4, Insightful)
Voyager was launched at an almost optimal time for gravitational slingshots, so that resource is already tapped out. If I recall correctly the planets won't align like that again until sometime next century and it still wouldn't go faster. In fact that was what gave it most of the speed so we need a lot better propulsion go get anywhere.
I hadn't heard of this so I looked it up. It turns out that the "Grand Tour" was for Voyager 2, which received gravity assists from Jupiter, Saturn, Uranus, and Neptune. It's true that those four won't be in a similar alignment until the next century, but Voyager 1 only received gravity assists from Jupiter and Saturn (and Titan). I haven't done the math or anything, but those two should line up at least a couple times each century (see the Cassini trajectory).
Some dumb, back-of-the-envelope calcs with existing tech: assuming a 50 mN Xenon ion thruster that can run continuously for 3.5 years (NASA's NSTAR did this) spacecraft, right now we can add about 11 km/s to a 500 kg spacecraft per thruster. New Horizons is 478 kg, so I figure 500 kg is a decent guesstimate (it would need a much bigger RTG to run even a single ion thruster for that long, though). Also, New Horizons will be traveling 13 km/s when it reaches the same distance as Voyager 1 with only a Jupiter gravity assist, so even with a less-than-optimal gravity assist I think we can easily beat Voyager 1's speed (turning on the thrusters after the last gravity assist, of course). It would still take us decades to pass it, but we could.
Still, that wouldn't take us to the Oort cloud in any decent amount of time. If we used a different nuclear fuel with a longer half-life we could stretch our ability to power it, but probably at the cost of peak power.
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Well, we'd have a much better chance with a vehicle up-close, but the Oort Cloud is still extremely diffuse, even compared to the Kupier Belt. It's possible that Voyager could speed right through it and never so much as spot a single pre-comet ice object.
On the other hand, if we actually designed a vehicle for Oort Cloud exploration, we could probably get it out there a lot sooner than 14,000 years. Still a very long time, but faster anyway. The Voyagers were set up for fast approaches to Saturn and Jupi
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u folks realize the Oort Cloud is a hypothesis right?
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Not any more.
In the last decade computer modeling has confirmed that long period comets are Oort Cloud objects which have had their orbit modified by passing stars, molecular clouds, or galactic tides so that they come close to the Sun. We have also discovered three "Scattered Disk" objects in the last year whose orbits take them more than 2000 AU from the Sun, the inner boundary of the Oort Cloud. The Scattered Disk and Oort Cloud have the same origin - scattering from the Solar nebula by the larger plan
Re: Oort Cloud (Score:3)
> Carl Sagan wrote a lot about the Oort cloud. It would be nice if we could get first-hand evidence of it
We have two types of first hand evidence. The first are long period comets, which spend at least 90% of their life at Oort Cloud distances. They are Oort cloud objects that just happened to have their orbit perigee shifted by passing stars, molecular clouds, or galactic tides. They get close enough to the Sun to boil off their ice content, which makes them easy to find, but otherwise they are still
Re:Hard to define (Score:5, Informative)
If we define the solar system as the sun and everything that primarily orbits the sun, however, Voyager 1 will remain within the confines of the solar system until it emerges from the Oort cloud in another 14,000 to 28,000 years
http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Voyager_1&Target=Beyond [nasa.gov]
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Its already pasted the ort cloud
No, according to NASA's Voyager project page [nasa.gov], Voyager 1 won't escape the Oort cloud (really the outer Oort cloud) for another 14,000 - 28,000 years. (Probably due to running out of power in the next 10 to 15 years.)
Newton (Score:5, Insightful)
Voyager 1 won't escape the Oort cloud (really the outer Oort cloud) for another 14,000 - 28,000 years. (Probably due to running out of power in the next 10 to 15 years.)
Perhaps I have misinterpreted your statement, but are you aware of Newton's First Law of Motion [wikipedia.org]? Voyager has no need for power to continue its journey; running out of power will have no effect on its velocity.
My guess is that, aside from attitude adjustment, Voyager hasn't fired its thrusters since its encounter with Titan in 1980.
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I would think given it's distance to target an LED being lit (if it had any) might be enough for slight attitude adjustment.
Either way if it's forward velocity reduces to 0 we'll know we found the Oort cloud. :)
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No... we won't know. Because its power will have been exhuasted and we won't be able to tell that it has actually stopped in the first place.
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Now granted, I don't think we can actually do something like that with the voyager spacecraft...
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Either way if it's forward velocity reduces to 0 we'll know we found the Oort cloud. :)
Or aliens.
Actually, given the assumed density of the Oort Cloud, aliens might be more likely.
So, I'm not saying that it will necessarily be aliens... but it will be aliens.
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Perhaps I have misinterpreted your statement, but are you aware of Newton's First Law of Motion [wikipedia.org]? Voyager has no need for power to continue its journey; running out of power will have no effect on its velocity.
My guess is that, aside from attitude adjustment, Voyager hasn't fired its thrusters since its encounter with Titan in 1980.
Newton's first only applies if the sum of forces acting on an object is zero. The pull from the solar system is non-zero, which is why V'ger has slowed down since then.
While it has enough speed to leave our solar system, it will slow down while doing so. And it doesn't have enough speed to leave our galaxy, but will, baring near encounters, eventually stop and be sucked back in relative to the Milky Way.
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Voyager has no need for power to continue its journey; running out of power will have no effect on its velocity.
You're forgetting drag. Just like flying through air, flying through parts of the solar system results in drag from dust. The dust density is expected to increase when the probe reaches the inner Oort cloud, unless Voyager 1's path has angled enough above the ecliptic that it manages to miss it (I thought 35 degrees was high enough, my colleague disagrees.) If dust density increases, the drag will provide a small but continuous slowing effect. Once past the inner Oort cloud dust density will likely dec
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Well, unless the universe does collapse someday, there should be parts of the universe that are being expanded away from us faster than the speed of light, which is also supposed to be the speed of gravity. We will never be able to observe those parts of the universe though.
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It is mind bending concept, but in reality, you're essentially not accurate when you say "parts of the universe that are being expanded away from us faster than the speed of light".
Wrong.
In fact, some of the galaxies that we can see today are now expanding away from us faster than the speed of light. The light we see is from billions of years ago when they were not.
Re:Hard to define (Score:5, Informative)
The galaxies are not moving relative to us, faster than the speed of light away from us. The space between us and those galaxies is growing, cumulatively, faster than the amount of time it would take light to cross that space. The Galaxies themselves may actually even be moving towards us. This is the cumulative effect of the very tiny expansion of the universe compounded by vast... nearly unfathomable distances. Eventually if the expansion continues, we'll not even be able to see nearby stars. But, of course, we'll all be dead long before that happens.
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Yes. The galaxies and stars will still be there, at least for a long time afterward, but the light from them will eventually redshift to the point where it ends up so deep in the far infrared that they become, for all intents and purposes, completely invisible to us.
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I'd say if it was outside of our star's sphere of influence [wikipedia.org], then it would be in interstellar space (assuming it was not in another star's sphere of influence)
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3rd article in past half year with same subject.
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Ouch!
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I think an argument could be made that true interstellar space is where the Sun's dominance over the environment fades to the point where other stars have similar or greater influence. This point might be inside the Oort cloud by a significant margin.
The metric being used today is cosmic radiation. The sun emits its own, which dominates the parts of the solar system we occupy - but it seems, where Voyager is now, that interstallar cosmic radiation now dominates.
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Re:Hard to define (Score:4, Informative)
Space is awfully empty. The odds of it actually striking anything in interstellar space are barely higher than zero.
Consider this: the Milky Way galaxy and the Andromeda galaxy are expected to collide in a few hundred million years. Even though there is a good chance that the collision will be a direct hit as opposed to a glancing blow, it is probable that not a single star from one galaxy will hit a star from the other galaxy (or be disrupted to hit one from its own). Space, even in densely-populated galaxies, is a very empty place.
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But Voyager could never gain on that, so it could travel almost indefinitely out into the universe and the Sun would still have at least SOME effect.
I for one welcome our new (Score:5, Funny)
V'ger overlord!
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That was actually Voyager 6 [memory-alpha.org], launched in the late 20th century, around the time of the Crazy Years. Or is that another future history...can't think straight with all these images of hot bald chicks running through my mind.
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I hope it escapes the fate that befell Pioneer 10 [memory-alpha.org].
Take care out there Voyager (Score:5, Insightful)
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And watch out for those Kazons, Hirogens and Borgs.
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This is nothing. Voyager is going to be pulled into the Delta quadrant soon.
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Wait, why does it cost $4 million a year to listen for and interpret the radio signal coming back?
Re:Take care out there Voyager (Score:4, Funny)
It costs around 500 thousands for a dozen or so engineers and 3.5 millions for the RIAA broadcasting license.
Re:Take care out there Voyager (Score:4, Funny)
Damnit, I knew putting that golden record on that thing would bring no good!
Re:Take care out there Voyager (Score:5, Insightful)
Salaries of experts? Facilities with dedicated antennas and support personnel? Things add up quickly.
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Wait, why does it cost $4 million a year to listen for and interpret the radio signal coming back?
Won't someone please think of the scientists!
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Actually - if you read the article, it was NASA management that proposed the cuts... but go ahead, blame Bush. Bias and ignorance is ever so much easier than reading and comprehending.
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NASA's Earth-Sun System division, which runs the program, amongst others, has had to cut its budget for next year from 74 million to 53 million dollars, calling for some project abandonments. The cuts for Voyager and other missions are planned to help fund President George W. Bush's "Vision for Space Exploration", his plan to return to the moon and a manned mission to Mars.
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Translation: To preserve my bias, I'll spin and twist and handwave... whatever it takes.
Anyone who thinks that programs as large and as long as those NASA undertakes can be done without management... and t
Cue the Star Trek jokes in 3... 2... 1... (Score:3)
Of course, neither probe in the ST movies was Voyager 1.
ST:TMP was Voyager 6
STV:TFF was either Pioneer 10 or Pioneer 11.
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Indeed it does; you should take your own advice. (In other words, "get back in the queue [i.e. line]" was correct.)
Now, cue the horde of grammar NAZIs queuing up to complain about my post in turn...
Not so fast (Score:5, Informative)
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The Voyager project's chief scientist says not just yet: http://www.jpl.nasa.gov/news/news.php?release=2013-107 [nasa.gov] Also, here's a fairly recent video lecture he gave on the topic that gives some good details: http://www.jpl.nasa.gov/events/lectures_archive.cfm?year=2012&month=9 [nasa.gov]
What is this the third time we had a story about it leaving the solar system? Some include the Oort Cloud in the solar system so are we facing hundreds of years of these announcements?
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ht [nasa.gov]
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No. We'd be facing thousands of years of these announcements. From NASA [nasa.gov]:
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Which influence? Heat? Light? Gravity? Magnetic? And at what point do we consider the influence ended? When there's no effect? Negligible effect? Very little effect?
And Thus, a Mighty Schism Borne Out Two Sects ... (Score:5, Funny)
Reformed Good Gamma Rays Church of the Accurate Voyager One-ist: "HERESY! Where I come from, we have reserved black holes for the likes of your foul and vile lie spreading mouth. Prepare for battle and death
Latter Day Voyager One-ist: "But I am merely repeating the preachings of Voyager One's one true manager, Edward Stone, who is one and the same with Voyager One!"
Reformed Good Gamma Rays Church of the Accurate Voyager One-ist: "Your Edward Stone was a false prophet and copycat of the original true manager that is lost to the ages!"
Latter Day Voyager One-ist: "Impossible, it was written that the oracle confirmed His information before being unplugged."
Reformed Good Gamma Rays Church of the Accurate Voyager One-ist: "How dare you bear false witness against the Wayback Machine (Voyager rest its all knowing soul)?!"
Latter Day Voyager One-ist: "Ask any Unified Voyager Two-ist, they agree with our views
Unified Voyager Two-ist: "Okay, everybody, drink your kool-aid now
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Must be Wednesday (Score:5, Insightful)
.
What I don't understand is why the linked stories don't mention how big a change in radiation was experienced. Are we talking 10%, or a factor of 10? How about a curve while we are at it -- could be it is gradual, could be sharp, could be a hockey stick -- curve us please.
Re:Must be Wednesday (Score:5, Interesting)
Looks like two orders of magnitude change in measurements (100 times). At least that's what the article I found here says: http://www.foxnews.com/science/2013/03/20/voyager-1-leaves-solar-system/?intcmp=features [foxnews.com]
Re:Must be Wednesday (Score:4, Informative)
"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, galactic cosmic rays – 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."
You're welcome.
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the linked stories don't mention how big a change in radiation was experienced. Are we talking 10%, or a factor of 10?
Yes they did, from TFA [agu.org]:
"Anomalous cosmic rays, which are cosmic rays trapped in the outer heliosphere, all but vanished, dropping to less than 1 percent of previous amounts."
and also
"galactic cosmic rays – 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"
Wrong site (Score:3)
There's a good detailed article at Ars [arstechnica.com] about that which is a better read than what /. offers (as so often, sadly)
What's the definition of "leaving the system"? (Score:4, Insightful)
Sorry if this sounds dumb to some of the astronomy cracks, but from what I gathered so far from astrophysics is that there are different speeds for leaving the "area" of a body. IIRC it is called the sphere of influence, where a certain celestial body is the one that affects me the most. Like here on Earth, obviously, it's that planet, despite the Sun being a LOT bigger and hence having a lot more gravity, but since I'm sitting on that rock, Earth is it for me. Now, when thrusting away from Earth, at some point I leave its SOI and the Sun will take over as the main body defining my "main body" towards I move relatively. And provided I do not end up in the SOI of any of the planets or moons in our solar system, that's how it's going to stay until I am so far away from the sun that something else will be my frame of reference.
So wouldn't "leaving the system" technically require exactly that? That I enter another body (or bodies) sphere of influence? And, another thing, does Voyager actually have enough push to leave the system for good? As far as I know it does take quite a bit more oumph to leave the Sun's SOI than Earth's.
Re:What's the definition of "leaving the system"? (Score:4, Interesting)
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Couldn't the galaxy itself be a SOI?
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As well, the SOI [wikipedia.org] is a discrete thing, similar to the Hill Sphere. I suppose they are just different ways of looking at the same thing.
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Voyager is moving *much* faster than it did when it left Earth. Using gravitational slingshots around the various gas giants allows it to add significant speed. I believe it's something like 10 miles per second currently.
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there is a limit to the distance at which it has any effect.
Voyager will never reach a point of "zero influence"
Pick one, it can't be both. You could perhaps argue that Voyager doesn't have the velocity to escape the Sun, but I believe simple physics proves that it does have the necessary velocity.
As the Sun is only 4.6 billion years old, any point in the universe more than 4.6 billion light years away feels no gravitational effect from the Sun whatsoever.
Not true. The mass of the solar system was already here 4.7 billion years ago and is now just a bit more concentrated, but it didn't substantially change. So it was having the same effect before and the same effect after. Just a very very very small effect at a 4.6 billion light year distance. So small as to not be not
Voyager 1 has already escaped solar system (Score:5, Informative)
To clear up any possible confusion, Voyager 1 doesn't need to enter the "sphere of influence" of another body to avoid falling back to the Sun. It has already escaped the Sun's gravitational field, long ago and by a large factor.
On September 9, 2012, Voyager 1 was measured to be 121.798 AU from the Sun and traveling at 17.043 km/s. At that distance, the escape velocity from the Sun is only 3.817 km/s, which Voyager 1's speed exceeds handsomely.
The dear thing isn't coming back, at least not without help. :-)
Longevity. (Score:5, Insightful)
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Largely its travelling through a vacuum, given the thing didn't explode seconds after it was released from the rocket, I'd say 36 years of travelling through a vacuum to be on par with expectations.
This is not like slamming a rover onto another planet with harsh temperature, wind and dust conditions and having it work 10 times longer then its original mission specs.
Re:Longevity. (Score:4, Insightful)
cosmic radiation. gravitational pulls. micrometeorites. for being essentially an uncontrolled hunk of metal on a purely inertia/tidal trajectory, it's pretty amazing.
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So it was supposed to fail in the 1980s/80s? :O
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Little known facts about Voyager:
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you're confusing Carter with Chuck Norris
Re:Longevity. (Score:5, Insightful)
Yes its like those Mars Rovers that only lasted days instead of weeks and months and years- their primary mission wasn't even accomplished! What poor workmanship and slave labor have wrought!
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Yes its like those Mars Rovers that only lasted days instead of weeks and months and years- their primary mission wasn't even accomplished! What poor workmanship and slave labor have wrought!
Or don't even last that long. For example:
I'm sure some Google time could provide a long list of failed Mars attempts...
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I was being sacrastic. Those two little rovers far outlasted their mission goals.
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No, if we built one today it would likely out live its mission plan as well. The difference is, it would not out last its mission plan ridiculously long periods like Voyeger. Thats a good thing, it means the design is closer to the intended design rather than being more than it needs to be.
When dealing with space, overbuilding is a tricky situation. Yes, you want to over build it so you KNOW it going to work in every possible situation (which of course is impossible ;), but you have to constraint that if
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just designing something that lasts longer than its mission goals is, when taken alone, an epic failure when you're talking about thousands of dollars per kilo to launch.
I disagree, for the simple reason that if we can spend slightly more incrementally and increase the service life significantly, we can keep getting data without having to design and launch a brand new system (for many more kilos of launch cost).
If we can spend one extra kilo and get 10 extra years of service, that's probably a good tradeoff. If we spend one extra kilo and get 100 extra years, that's a great tradeoff.
Re:Longevity. (Score:5, Funny)
Heliopause (Score:5, Funny)
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Just wait until the moodiness starts...
Last transmission (Score:2)
F**k, there's nothing out here! They lied to meeeeeeeeeeee...
Voyagers onboard computer (Score:3)
No, it wasn't the Eniac.
"There are three different computer types on the Voyager spacecraft and there are two of each kind. Total number of words among the six computers is about 32K."*
[*] - http://voyager.jpl.nasa.gov/faq.html [nasa.gov]
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A bit more info for history buffs...
Originially, there was some thought given to the tradeoff between a single centralized computer, and a distributed computing architecture. After much analysis, the 3 dual-computer configuration was selected.
The CCS (computer command system) is essentially identical to the computer used in viking.
The AACS (attitude and articulation control system) is sort of a souped up version of the CCS (higher clockrate, added "index" registers + a few opcodes)
The FDS (flight-data sub-
Scale model of its path and location? (Score:2)
I'd like to see a good diagram of what its general path was and where it is now in relation to other planet orbits if anyone knows where I can find one.
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I had 125 AU in the office pool (Score:2)
You know, when Voyager clangs off a giant glass shell with star lightbulbs screwed into it. NASA's going to be pissed, but I bet I'll get $80 out of it!
I could learn via Google, but (Score:3)
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The sun's effects might be different in polar directions versus equatorially - it might be interesting to learn. However, only captured objects would orbit the sun in such directions so until we can get into interstellar space quickly, there's likely little benefit in going in such directions.
Message from the "new realm" (Score:2)
"My God, it's full of stars!"
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No, they are really really really sure that something is really really different now. They have noted two orders of magnitude changes in their measurements so they are in a different, rather well delineated region, that doesn't match their expectations but is clearly not the same as what they saw when they where clearly inside the solar system.
Of course... It could just be the space craft starting to malfunction... Or some alien life form has taken it over and has decided to mess with our minds... I'm sur
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...and we are still standing on the shoulders of our past Geniuses. Oh how far we have fallen.
Technically, it's a little *under* 36 years later, as Voyager was launched on September 5, 1977, so be careful about lamenting the fallen, Grasshopper, until your simple Math skills improve. :-)
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I'd always hoped she'd marry Afrika Bambaataa.
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Psst. They're our signals coming back to us from Voyager. Source of the signal is human technology and thus (ostensibly, but I'm starting to wonder) intelligent.
tl;dr:
Whoosh.
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