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Voyager 1 Crosses The Termination Shock
SubstormGuy writes "In a scientific session at the AGU meeting in New Orleans this morning, Dr. Ed Stone presented clear evidence that Voyager 1 crossed the termination shock last December. The scientists in the room applauded when the announcement was made."
...voyager fans, unsure what "termination shock" exactly means, start raising donations "just in case".
The first link doesn't go anywhere useful. This link brings up the correct results for the session. You can also view the session details.
I am shocked I say -- SHOCKED -- to hear this news.
And excited.
The geek in me is excited about 2005. Methane oceans, rovers on Mars and private spaceflight? There's a lot that's scary going on in the world today. But when it comes to SPACEFLIGHT -- 2005 is shaping up to be a banner year!
Kudos to the Voyager team!
I would have to say that explosives are the most abused technology in all of history.
Worlds grow old and suns grow cold
And death we never can doubt.
Time's cold wind, wailing down the past,
Reminds us that all flesh is grass
And history's lamps blow out.
But the Eagle has landed; tell your children when.
Time won't drive us down to dust again.
Cycles turn while the far stars burn,
And people and planets age.
Life's crown passes to younger lands,
Time brushes dust of hope from his hands
And turns another page.
But the Eagle has landed; tell your children when.
Time won't drive us down to dust again.
But we who feel the weight of the wheel
When winter falls over our world
Can hope for tomorrow and raise our eyes
To a silver moon in the opened skies
And a single flag unfurled.
But the Eagle has landed; tell your children when.
Time won't drive us down to dust again.
We know well what Life can tell:
If you would not perish, then grow.
And today our fragile flesh and steel
Have laid our hands on a vaster wheel
With all of the stars to know
That the Eagle has landed; tell your children when.
Time won't drive us down to dust again.
From all who tried out of history's tide,
Salute for the team that won.
And the old Earth smiles at her children's reach,
The wave that carried us up the beach
To reach for the shining sun.
For the Eagle has landed; tell your children when.
Time won't drive us down to dust again.
(c) 1975 - Leslie Fish
I want a new world. I think this one is broken.
if NASA does not terminate the project to favor Bush's push to put humans on Mars, the Voyager 1 has enough power to last another 15 years (2020). in that case, they should be able to retain enough data to calculate what is going on in the heliosheath and beyond. I don't think 'hot' is used to describe a location that is 7 billion miles from the sun :-} .. but they should be able to calculate a close temperature based on the distance and magnetic fields among many other factoring (IANAS)
do you have shinyfeet?
hehe, yes. All too often I see references to the speed of sound at sea level when the vehicle in question is most definitely not at sea level.
How we know is more important than what we know.
The termination shock is basically where the wind of the sun meets "the wall" -- as known as interstellar medium.
You know about the solar wind. It's basically a stream of particles flowing out of the Sun's atmosphere at a supersonic speed. The particles would cruise radially out of the Sun and go on and on and on...until it meets a clump of gas associated with semi-primodial stuffs that the Sun and other neighboring stars were made out of. Imagine that the Sun is sitting in a void of space (the emptiness was due to the solar wind sweeping out the material around it).
Anyway, as the particles in the solar wind nears the wall, the particles in the solar wind begins to "feel" the presence of a wall. It's like a wind hitting a building and twirl near the wall of the building. A similar thing happens here and the sensors on board Voyager can sense the motion of these particles "twirling" around. In this case, these particles are slowing down and that's what Voyager I has detected.
As for the precise timing? I don't think there is a clear signature of the "termination" point. It might have been in 2003 or in Dec 2004. In the astronomical standpoint, the distinction is, I believe, not so meaningful.
Phew. That's alot to write. I'd better go to bed now.
Cool indeed. I can't help but wonder what Carl Sagan would think of this if he were around to see it happen....Sadly we have only his past eloquence to ponder and we are now left to our own devices in order to comprehend the magnitude of this event. We are now an interstellar species. The first ever on Earth and the only one we know of. There is no turning back now. Though perhaps it is time for Voyager to turn back, one last time to send us an image of ourselves from the incomprehensible beyond. Our planet will of course not be visible anymore, and our sun will probably appear as a mere unremarkable dot among a thousand others.
- "Hear that?! The percolations are imminent! Cease your ingress!"
the bbc http://news.bbc.co.uk/1/hi/sci/tech/4576623.stm has some more info on this. You should know that they are not 100% it has crossed the termintation shock. "Some researchers thought the probe had arrived at the shock; others thought it still had some way to go. Now, at the 2005 Joint Assembly meeting organised by the American Geophysical Union, space scientists say they are confident - and agreed - that Voyager has gone beyond the termination shock and is flirting with deep space. Predicting the location of the termination shock was hard, the researchers say, because the precise conditions in interstellar space are unknown. Also, changes in the speed and pressure of the solar wind cause the termination shock to expand, contract and ripple. The most persuasive evidence that Voyager 1 has crossed the termination shock is its measurement of a sudden increase in the strength of the magnetic field carried by the solar wind, combined with an inferred decrease in its speed. This happens whenever the solar wind slows down."
I am totally depressed by my inability to make a Star Trek: The Motion Picture joke.
Just goes to show that maybe a source that ANYONE can stick any random crap into might not be the most reliable.
Not really, in this case it showed that an article that's out of date may not be correct. I mean, the new information was just now announced. To clarify, these articles now seem to be correct according to my source, and read:
- "Scientists at the Johns Hopkins University Applied Physics Lab believe that Voyager entered the termination shock in February 2003."
- "Evidence presented at the AGU meeting in New Orleans in May 2005 by Dr. Ed Stone suggests that the Voyager I spacecraft passed termination shock in December 2004."
Beware: In C++, your friends can see your privates!
Is anyone else frustrated when you hear wonderful science like this being done, yet see that probes like this are slated to have their funding cut (http://www.spacedaily.com/news/voyager1-05a.html) ? For some reason, $4.2 million / year to operate them (ie, listen) seems unbelievably cheap for such a unique resource - not only are there only TWO probes out there (voyager 1 and 2), but to get others out to replace them would cost a whole ton more. ...In addition to having to wait another 20 or so years to get there. :(
Science just doesn't work when politics gets involved...
For those who want to know what a termination shock looks like: Clicky.
envious of Americans. We 'foriegners' give you guys A LOT of crap over wars, the environment, religion, guns etc (not that the British have a leg to stand on... we forget our history way too quickly), but the fact is that we don't have the balls to do anything like this anymore. Creating an object that can travel out of the Solar System is HUGE. It is an achievement that should stand out as a moment in history that we can be truely proud of: no-one got killed, you're not doing it for greed or wealth - its a pure scientific achievement.
Scared of flying, pointy things snce 1979!
I don't think 'hot' is used to describe a location that is 7 billion miles from the sun
:).
Actually, "hot" (or temperature) is really describing the energy of the particles in the area. Inside the solar system, the solar wind is moving at pretty high speeds - wikipedia suggests energies of 500 KeV. Using the Boltzmann Constant we get 500,000 x 11,605 = 5.8 billion degrees K (Sounds a lot - can some astrophysacists check my figures please
Once you get to the termination shock, the solar wind is moving at much slower sub-sonic speeds. Not sure what energies we're talking about here but they're going to be a *lot* lower... A bit of googling suggests He energies somewhere around the 5.2 KeV area (5,200 x 11,605 = 60 million degrees K).
Of course, although the matter may be "hot", there isn't much of it - the low density of matter means that there isn't much "heat" (compare - a cigarette is "hot" (it's gonna burn you) whereas a central heating radiator is not as hot but generates more "heat" (it'll warm your room better than the cigarette because it's total energy output is much greater, even though it's temperature is less)).
Disclaimer: IANAAP (Astro-Physacist) so the above could be crap, but that is how I understand it.
http://blog.nexusuk.org
They don't really KNOW that that it crossed that TERMINATION SHOCK thingamajigger. The termination shock isn't mentioned EVEN ONCE in the bible, new OR old testament.
Ha, you don't have a very good translation do you?
It says right here after, "Thou shalt not pop-off around the corner for a pint," that, "Thou shalt enjoy thine termination shock so long as thou art not seen to be smug about the business. Thine undergarments must be clean at the time of the shocking of the termination. Thusly, shalt the word of the Snazzites be proven unworthy of the jigsaw-mongerer. And all will be well in Geziphalohn."
See? Plain as day.
I'm so glad that taking care of our retired is thrown in with welfare. Thanks for sharing, fascist.
Amen. The poster should be ashamed of themselves, and the moderates who modded you down as "flaimbait" for speaking the truth even more so.
1) Social Security isn't "welfare." We pay into the system, we get benefits out of the system. Social Security recipients are not getting "something for nothing," so to lump them in with welfare recipients is just plain Ignorant(tm) and Stupid(tm).
2) You want to discuss welfare, start by discussing the savings and loan bailout, the tax subsidies virtually every large corporation gets from state, local, and federal governments, and the immense amount of government pork in the defense budget which amounts to Yet Another Subsidy. The amount of tax dollars spent on corporate welfare, an appalling percentage of which goes directly to line the pockets of the very wealthy, dwarfs by an order of magnitude the amount of money being returned to those who've paid into the Social Security system, being paid to those who've paid into the Unemployment Benefits system, being returned to those who've paid into the Medicare and Medicaide system during their working lives, and yes, even those getting free handouts ('welfare') because they're too poor, too uneducated, lack resources, lack opportunity, or (in some cases, but not even close to all) are simply too lazy to work.
That doesn't change the fact that funding the space agency should be one of our top priorities, not one of our last, but to blame it on "welfare" is numerical nonsense--and to blame it on the modest, half-assed social programs we call Social Security and Medicare simply unconscionable right wing and, yes, fascist dogma. The Right in America has become so toxic it boggles the mind.
The Future of Human Evolution: Autonomy
An accident at launch could have released highly toxic materal from the plutonium batteries.
While this is true, my basic problem is that most people opposed to RTGs can't understand this statement in context. The environmental impact statement of this project is particularly useful. Its in this PDF on page 19. But let's analyze that statement anyway, piece by piece.
1) An "accident" could have released material, but it was unlikely. The containers were tested under explosions, fires, shrapnel, reentry heat, and impact. The RTGs were tough enough that they could hit concrete at terminal velocity and release only a minscule amount of fuel (0.22 grams).
2) Yes, Plutonium is "highly toxic". But most people complaining about the RTGs don't worry about "toxic". They worry about "nuclear explosion" or "fallout". Of course, none of those can result from the failure of an RTG. 10kg of toxic material (only a fraction of which would actually be released in a failure) is hardly your biggest worry. I'd be more worried about the thousands of pounds of very nasty fuel in solid rocket boosters.
3) The fuel in the RTG's isn't plutonium, its plutonium dioxide. This is an important difference, because the latter is very stable, almost inert (it was believed to be completely inert until 1999), and is insoluable in water. It also has a very high melting temperature and an even higher vaporization temperature. The net result is that the mechanisms through which it can enter the environment in the event of an accident are very limited. Basically, it would have to be bulverized and become airborne. Pulverizing 10kg of a hard material encased in a strong, unrestrained container, with just a single explosion is non-trivial. The physics of the situation tend to make the container just fly away and land in the dirt.
So basically, an accident was exceedingly unlikely, and even if it did happen, release was unlikely, and even if that happend, you had bigger things to worry about at that point.
You can operate on a basis of reasonable risk management
It's not "reasonable risk management". It's "not caving in to complete paranoia".
assuming the general public is entirely ignorant of physics
The general public *is* ignorant of physics.
I'm sure there are plenty of people in the "general public" who have studied more physics and bio/chemistry than you have.)
Well that's fine and good, and I don't doubt that biology and chemistry can tell you that plutonium will cause poisoning and cancer. However, biologists and chemists are not engineers or environmental scientists. They cannot tell you the probability of an RTG failing in an explosion, nor can they tell you the environmental mechanisms through which plutonium could spread even in the case of a failure. Nor can they tell you what sort of population impact such a spread would have anyway. Finally, they are not trained to make risk assessments of this nature. Engineers build bridges (and planes and cares and buildings), that thousands of people trust their lives too every day, without a second thought, using the exact same risk assessment mechanisms the NASA folks used. If you're going to question the NASA folks, the intellectually honest thing to do would be to grill the guy who designed your car about what risks he took with your life.
I agree that people sometimes go way overboard with their resistance to anything nuclear, but that attitude was instilled in them, or their parents, pretty forcefully.
Most parents are people, and most people are stupid, therefore most parents are stupid. Is having stupid parents supposed to be an excuse for being ignorant?
And it doesn't help the situation one bit, when the only response when concerns are raised is "go away, you are ignorant"
What if "you are ignorant" is the correct answer? I do not buy the idea that it is the du
A deep unwavering belief is a sure sign you're missing something...