

Confirmed: Voyager 1 in interstellar space - kneth
http://www.space.com/26462-voyager-1-interstellar-space-confirmed.html

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cryptoz
> Interstellar space begins where the heliosphere ends. But by some measures,
> Voyager 1 remains inside the solar system, which is surrounded by a shell of
> comets known as the Oort Cloud.

See you next July! I look forward to reading this story every year for the
next 50 years or so. Maybe I'll pass it in some spaceship and be reading
stories about how it's leaving the solar system.

~~~
yebyen
I'm not really informed about these things, but if you asked me for my
opinion... Voyager 1 is not out of our solar system until it's caught in the
gravity of another one. In other words, if it was possible to bring it to a
full stop and take a measurement, when gravity pulls it in another direction
away from our sun, it is outside. That could be quite some time longer?

~~~
delucain
I don't think that's a fair assessment. It would be like saying you haven't
left your town until you see another one.

And bringing Voyager I to a full stop is currently impossible. It doesn't have
the fuel and is traveling at incredible speed. Although, technically the
velocity is relative to our own. It very well may BE stopped relative to some
other object in space.

If it were pointing at Proxima Centauri, the nearest star system to ours, it
would take 75,000 years, give or take, to get there.

------
flohofwoe
Relevant xkcd: [http://xkcd.com/1189/](http://xkcd.com/1189/)

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InclinedPlane
The quality of the top level comments here is exactly why I cringe whenever I
see a science story on HN these days.

~~~
dclowd9901
Sounds like a good time to disrupt.

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optimusprinceps
What exactly is propelling Voyager through interstellar space?

~~~
chton
The speed it already has. There's practically no friction in space, so any
speed it picked up from its engines and gravitational slingshots is kept.
Newton's first law.

~~~
batbomb
and 30 years of any radiation pressure.

~~~
chton
that's a good point. It's impossible to measure the effect of this on the
Voyagers because they still constantly fire attitude control thrusters to
align themselves to earth. The noise on the speed from those firings is too
much to distinguish solar radiation pressure.

~~~
astrodust
Actually they can measure this with great precision. Consider how they were
able to isolate the "Pioneer Anomaly"
([http://en.wikipedia.org/wiki/Pioneer_anomaly](http://en.wikipedia.org/wiki/Pioneer_anomaly)),
an extremely tiny amount of deceleration caused by radiation from the reactor.

If they can measure the drag caused by radiation, you can bet they can account
for solar effects.

Also worth noting: The thrusters are fired very infrequently. According to
that page, the Voyager missions required constant adjustments but the Pioneer
system is spin stabilized.

~~~
chton
That's exactly the problem. Because Pioneer was spin-stabilized, it didn't
need to fire thrusters, so the noise wasn't there and the anomaly could be
measured. Voyagers aren't spin-stabilized, so they have to fire thrusters
quite frequently. That makes it impossible to measure a small enough effect on
them.

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sigsergv
Again?

~~~
chton
Not again, they're basically saying "Remember the last time we said it? turns
out we were right."

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lavamantis
Oh crap. Now we've done it. This thing is going to encounter an alien race of
machines, get smart, and come back and hold the earth hostage while looking
for it's long lost creator!

