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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.
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?
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.
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.
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...
On behalf of my fellow Americans, whether they like it or not, I'd just like to say thanks for your comment. Not that I had anything to do with Voyager or any other sattelites up there. In spite of some of the bad things we've done, I'm proud of my country (as I'm sure you are of yours), and I'm glad to see someone who doesn't judge all Americans based on a subset of our population.
Just like all countries, we do good things and we do bad things. We have good politicians and we have bad politicians. We have good people and we have bad people. So, thanks again for your levelheadedness, in all seriousness, I really do appreciate it.