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Voyager 2 Set to Reach Termination Shock
Invisible Pink Unicorn writes "A computer model simulation developed at UC Riverside has predicted that in late 2007 to early 2008, the interplanetary spacecraft Voyager 2 will cross the termination shock, the spherical shell around the solar system that marks where the solar wind slows down to subsonic speed. At the termination shock, located at 7-8.5 billion miles from the sun, the solar wind is decelerated to less than the speed of sound. The boundary of the termination shock is not fixed, however, but wobbly, fluctuating in both time and distance from the sun, depending on solar activity. Because of this fluctuation, the spacecraft is also predicted to cross the boundary again in middle 2008. The article abstract is available from The Astrophysical Journal."
speed of sound... wait a minute? In which medium? I don't think there is much atmosphere up there...
What exactly is the speed of sound in a vacuum?
If you are not allowed to question your government then the government has answered your question.
but can someone describe in layman's term what will that mean for the probe (if anything), will it change course/direction? can this negatively affect the mission/spacecraft itself?
this is the kind of thing scientists predict all the time and observe in lab experiments... but this device is actually GOING to the edge of a solar system... it's someplace human made instruments haven't been. Science at it's very purest form, simply going and observing something nobody has actually seen before.
Why do you go on vacation to foreign places.. aren't postcards and Discovery channel good enough? It's a whole lot different to say "we were there" than guessing what it would be like from a long distance.
Now that the tailwind has slowed down.
There's a Voyager 2?! Oh God no; come back Enterprise, all is forgiven...
== Jez ==
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"The boundary of the termination shock is [...] wobbly, fluctuating in both time and distance from the sun"
Are you SURE that it fluctuates in time from the sun, or do you actually mean that it fluctuates (only) in distance from the sun? Then there's this beautiful piece of prose:
"... Voyager 2 will cross the termination shock, the spherical shell around the solar system that marks where the solar wind slows down to subsonic speed. At the termination shock [...] the solar wind is decelerated to less than the speed of sound."
And finally:
"Because of this fluctuation, the spacecraft is also predicted to cross the boundary again in middle 2008."
Ignoring the poor English, care to explain the logic behind this? Surely, going from inside to outside, Voyager 2 will have to cross the boundary an odd number of times? Ladies and gentlemen, I suggest that this is worst article EVAR on slashdot. I rest my case.
It means Janeway's going to have to pretend to be thrown all over the place while bits of the ship fall off.
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Anyone else notice the related stories on the news site?
Nov. 6, 2003: Voyager Spacecraft Approaches Solar System's Final Frontier
Dec. 19, 2000: Most Distant Spacecraft May Reach Shock Zone Soon
May 25, 2005: Voyager Spacecraft Enters Solar System's Final Frontier
Besides the speculation, will we even know when the boundary is crossed? Do they expect data to indicate a transition, or do we even know if the instruments can detect such a thing?
Dan East
Better known as 318230.
Speaking as someone working on the project, posting anonymously for obvious reasons, I can give a little info. When the spacecraft reaches termination shock, it is quite likely that all the transistors will fall off the pcb's that make up the electronics. Chances are this isn't so bad, as their are lots of backup resistors, but if theres a leak in the spacecraft's petrol tank then it might be ignited by some arcing currents, which would probably throw it off course a bit.
No, it is not. It is the interstellar medium. Read: termination shock.
>Why do you go on vacation to foreign places..
I think you will find he is an american, and therefore that doesn't apply.
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they will be used to get data from voyager 2 on conditions at the edge of the solar system
however, a wobbly spacetime continuum means that voyager 2 must be running linux
because the wobbly spacetime is an infinite loop, only linux can escape it in 5 seconds
but time at the termination shock is slow enough that 5 seconds will be 2 years
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The speed of sound isn't a constant, and space isn't a total vacuum.
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Why do you go on vacation to foreign places...
OMG, underage Taiwanese hookers...in space?I swear to God...I swear to God! That is NOT how you treat your human!
Four, just four small space probes.
Sorry dude, all the space ships you see on TV are just FX. We are not (yet) exploring the galaxy. Will we get any new data about "termination shock" or whatnot? Yeah! We may confirm that there exists this termination shock we expect to find there, or we may find our theories are wrong and there is not such "thing".
Want to see the actual orbital trajectories of the Voyager probes for yourself in 3d type of thing? Because you can, if you use my nBody modeling software.
If you go here:
http://code.google.com/p/nmod/downloads/list
and get the windows installer or linux source for my nbody modeling kit, and then download this:
http://www.politespider.com/nbo/time_series.zip
And unzip it to save you the bother of having to actually generate your own time series (3d time series model of the solar system), which can take a while. You can then watch both Voyager probes follow their orbits (with 24th august 2006 as their starting date), for 20,000 days of travel time.
This isn't a program with a scrummy easy interface I'm afraid, the viewer is console opengl. But there are instructions here:
http://code.google.com/p/nmod/wiki/nbview
And it's not too hard once you get the hang of it.
The orbits do not take termination shock into account, this is pure Newtonian motion. The dataset for the solar system has taken months to put together. It's incomplete, It only has our moon (zoom in for ages with Earth centred and you'll see it), the others have been tricky to get right.
Once to get outside the boundary, twice if the boundary expands and catches back up with it, and thrice to once again get outside the boundary.
Just a thought.
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What is the speed of sound in a vacuum? Kinda existential...
Imagine if you weren't allowed to use roads because a bus company complained about your driving 3 times. --skunkpussy
It's going to reach the edge of the simulation, where it'll get rendered in lower resolution.
-- Only information exists, the rest is just smoke and mirrors.
What you are refering to is Voyager 1. TFA is about Voyager 2. They are two different vehicles.
<wikipedia href="Heliosphere">
Evidence presented at a meeting of the American Geophysical Union in May 2005 by Dr. Ed Stone suggests that the Voyager 1 spacecraft passed termination shock in December 2004, when it was about 94 AU from the sun, by virtue of the change in magnetic readings taken from the craft. In contrast, Voyager 2 began detecting returning particles when it was only 76 AU from the sun, in May 2006. This implies that the heliosphere may be irregularly shaped, bulging outwards in the sun's northern hemisphere and pushed inward in the south.
</wikipedia>
That's garbage. Space is not a total vacuum, it's true. However, the density of particles of matter in space is, for the most part, so low that space can be treated as a vacuum. It's like rounding 0.1xE-25 to just 0.
And as for the whole thing about sound travelling faster in space, you just made that up. Light (and other electromagnetic phenomena) do travel faster in a vacuum like space (perhaps you've confused the two). Sound, however, is caused waves of physical compression. In other words, one particle bumps into the next, which bumps into the next, and so on. Sound travels faster and farther through more solid materials. It has a certain speed and a certain distance it will travel in air, a faster speed and greater distance in water, and an even faster speed and greater distance through concrete. It has no speed or distance at all in space, because what little matter there is isn't close enough to touch the next peice of matter, and you can't set up the compression wave.
Beware of bugs in the above code; I have only proved it correct, not tried it.
...it will land with a "kerPLUNK!" into a half full goblet of mead at the foot of Zeus.
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As another reply already noted, this is the interstellar medium, which should be a good deal dense than the space between galaxies and galaxy clusters.
Next, how does sound transmit? Well, sound is a density/pressure wave, right? All I need is for the free particles to be interacting somehow to set one up. Turns out, the interstellar medium isn't a gas like you're used to thinking of, it's a plasma. The important point here being that because the electrons are not bound to the atoms, the effective "size" of the atoms goes up (that is, the disntance over which they interact with neighboring atoms). Thus you should be able to get sound waves more easily than you would suspect from a regular gas that is that sparse.
Plasma, meet speed of sound.
"Why are you so high, for my low density?"
"Because you are plasma, and no stupid ideal gas, slowpoke!"
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
The Pioneers were dead when the left the solar system. The Voyagers are still sending data.
Clear, Dark Skies
Because few governments expect to still be in power in 30 year's time, so what's the point? Cynical? Me? Never... ;)
It's worth pointing out that the primary missions of the Voyager probes were to explore the outer planets, which they did with great success many years ago (and we have sent more probes since). The fact that they are still active now and sending back useful information about the termination shock is just a bonus, so what you say about only sending two being a risk isn't really valid.
A termination shock/shockwave/bore/hydraulic jump occurs when the bulk speed of a fluid drops below the wave propagation speed.
Run a tap in to a flat sink (like a kitchen sink) and you see a circular pattern (if the sink is flat) some distance from around where the water hits the sink. The pattern should have shallow fast moving awater close to where the jst hist the sink, and deeper slower water on the other side of the circle.
The "jump" where the water goes from fast to slow is the same kind of object as a termination shock. For extra fun, stick an object in the slow water, and see how waves propagate ahead of it (against the flow). Then see how it doesn't happen in the fast water.
SJW n. One who posts facts.
We can't do this _every_ year because the reason the Voyagers made it out so far was gravity assist.
But I agree, I'd like to see NASA funding going to a lot of smaller projects like this than one behemoth one.
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I can't wait to see the pictures of the Restaurant.
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Actually no. The spacecraft would have crossed the boundary twice and the boundary would have overtaken the spacecraft once.
You can say you crossed the threshold of a door by walking through it. But if you stand still and the door suddenly flies past you, I don't think you can claim that you crossed the threshold.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
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Or we could work on nuclear propulsion and get there in no time... you can build an 8M ton ship that can go 10% the speed of light using 1960s technology... http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) of course it drops H-bombs out the back onto a metal plate so it isn't super eco-friendly...
This is the effect of minute "dust" particles permeating space and absorbing/deflecting light. The effect is less for longer wavelengths which is why we can get a better view of the Galactic centre in the infrared.
Europeans in general don't understand this, and it's probably true for most of the rest of the world. From where I live I can make it to Mexico in about 12 hours of solid driving, or to Canada in about 20 hours, but in most places in the US it's a day or more of travel time to either country. In most of Europe you can be to another country in an hour or two. Now, I've lived in both Italy and Germany (for about a total of 5 years of my life), and when I'd be talking to people, they'd talk about wanting to travel to the US and all the places they'd like to see. Want to see LA, San Francisco, New York, New Orleans, Grand Canyon, Yosemite Valley, Yellowstone, etc., and expect they could manage this in about two weeks, which, by comparison, is like wanting to travel from Moscow to London and hit all the major points in between in that kind of time frame.
The reason why many Americans speak only one language or don't spend a lot of time in other countries is based in this. For a majority of Americans there is only one language besides English that is of any utility, and that is Spanish. I was once fluent in both German and Italian, but since I've been back in the US I have yet to run into a situation where I needed to speak either language. It's not like we can day trip to France or that most businesses can deliver finished products to a foreign country with a simple truck ride of 3 or 4 hours.
If your talking high culture then yes Manhattan is pretty much our epicenter. I have only been to DC on guided tours, so the only culture I experienced there was tours of the Smithsonian, government building and monuments.
Now in terms of folk culture, you are wrong. First of all the world epicenter of low culture is Queens NYC, possibly the most ethnically diverse area of its size on the planet. Secondly, if you can't tell the difference between different parts of the country then you need to open your eyes. Compare New York and California for example. Even though a small but sizable portion of the population regularly travels between the LA and NY metro areas, the cities have completely different feels. Try finding good grits in the North East, or decent Italian food in the South, minus a few places with significant migration from New York.
I just love when Americans (who know I am foreigner from the other side of the ocean) ask me whether I went back home for Thanksgiving, and I study in one of the top 25 universities in the USA. I can never understand how people can ace Calc IV without studying and yet they are too ignorant to know that Georgia isn't simply a state. It's nation with a 3000 year old history, no less.I have two counter points to that.
First of all good at math does not mean good at history. If they are that good at math, and don't care for geography, they can survive just fine in college. I know a brilliant Mathematicians and programmer that probably didn't know where Prague was until he had to fly there to enter his physics engine into a competition. I would think that brilliant mathematicians in Georgia that do not study overseas have a narrower world view than you do. Also, I'm also sure Americans that study overseas have a firmer understanding of the world then their classmates.
As far as people asking you how your thanksgiving was, we Americans are known for engaging in mindless smalltalk. Most people probably didn't think out their statement. They also probably didn't care about your holiday. Finally how many of these people know you are in this country alone and not with your family.
--- Justin Dearing http://www.justaprogrammer.net/ We're just programmers.
Not ever, actually. It would need to go pretty fast -- the escape velocity needed to escape our galaxy from the vicinity of the Solar system is around 1000km/s.
We have ever launched 5 spacecraft going fast enough to escape out of the Solar system, at mere 11-ish km/s at the Earth orbit ("-ish" because we cheat a bit using gravitational slingshots).
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
Obviously, you've visited a few cities as a tourist. You've fallen for tourist view of any city, visited landmarks, etc. If you've lived all over the US, you would have realized that large cities have ethnic neighborhoods where English is not always the first language. Polish, Spanish, Italian, Hmong, Irish, etc. Hell, English isn't always understandable from various parts of the country.
I asked my co-worker what she was doing for Thanksgiving. She was going back home... to India. I may even ask her what's she's doing for Christmas even though she's not Christian.
While there are dumb, socially-inept, or culturally unaware Americans, are you sure they know you're from the other side of the ocean? A Georgian (country) accent isn't enough to say you're from another country.
LOL, I love the comment about India being a shithole. Just shows how much you know foreign countries.
I never said that Europe is the pinnacle of human evolution. They have their own set of problems, they let racism take priority over economic interests unlike Americans who are racist but will let you work in the USA if it economically benefits. Europe has fuckloads of bad things about it. But that's not my point...
My point is that culture within the USA tends to be very similar. It's pretty much the same shit everywhere. Strip malls, ghettos and downtowns. There are very few landmarks worth visiting if you are not American. Compare the landmarks in say Washington with any major European city.
The reason why I study in the USA is because I am not a dumb asshole like you. America has a better University system and it has more economic opportunity if you are a non-citizen (compared to Europe). Unlike you, I am not some mad fanatic who gets insulted by every random thing you say about their country. Get over it man, America has no culture. All your public holidays are just consumerist rage fests, you have no real history, you have very few cool landmarks (with the exception of NY). But that doesn't mean USA is a pile of shit, what it lacks in culture it makes up for in economic competitiveness.
It's funny that you talk about genocide considering that USA was founded on the mass eradication of the Native American population.
Chill out man, nation states are a load of bullshit anyways.