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Voyager 1 Reaches Interstellar Space
letxa2000 writes "CNN is reporting that Voyager 1, now some 8.4 billion miles (90 AUs) from the sun, has left the solar system and entered interstellar space by reaching the heliopause. However, whether the probe has reached the heliopause or is just coming close is the subject of two papers to be published in Thursday's Nature Magazine. The probe supposedly has enough nuclear fuel to last until 2020. Will it be able to find anything interesting outside the solar system in the next 17 years?"
Do you guys have any idea how much RAM had to be added to the Matrix to extend the simulation out that far?!
Kevin Fox
They've gone to plaid.
Life is the leading cause of death in America.
Heliopause
From Wikipedia, the free encyclopedia.
The heliopause is the boundary where our Sun's solar wind is stopped by the interstellar medium.
The solar wind blows a "bubble" in the interstellar medium (the rareified hydrogen and helium gas that permeates the galaxy). The point where the solar wind's strength is no longer great enough to push back the interstellar medium is known as the heliopause, and is often considered to be the outer "border" of the solar system.
The distance to the heliopause is not precisely known. It is probably much smaller on the side of the solar system facing the orbital motion through the galaxy. It may also vary depending on the current velocity of the solar wind and the local density of the interstellar medium. It is known to lie far outside the orbit of Pluto. The current mission of the Voyager 1 and 2 spacecraft is to find and study the heliopause.
An alternative definition is that the heliopause is the magnetopause between the solar system's magnetosphere and the galaxy's plasma currents.
Voyager 1 has reached heliopause and is now experiencing hot flashes and irritability. Hormone replacement therapy has proven innefective thus far.
NASA's page on the heliosphere
Dogma - "let's just say we'd like to avoid any empirical entanglements."
Detailed answer: Yes.
Questions that can still be investigated by Voyager include a number of questions about the interaction between the solar wind, solar magnetic field, and interstellar medium, direct measurements of the interstellar magnetic field, the actual composition of interstellar gas, where exactly the heliopause lies, and how it's affected by changes in solar activity. I'm sure there are even more questions that I haven't thought of.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
That's how long it takes a signal to reach us from the probe. When you consider the galaxy is 100,000 light years across, 8.4 billion miles is nothing.
90 AUs (Distance from the Sun to the Earth)
*
8 minutes (Time it takes light to reach Earth from the Sun)
=
720 Light Minutes
/
60
=
12 Light Hours.
We're quite a ways away from the Light Year.
Yes, the US government has a secret message it uses to identify this point:
.. Can you hear me now?"
"Can you hear me now?
Voyager uses a radioisotope thermoelectric generator for its power. This means that radioactive decay of its fuel creates heat, which is used to create power. That fuel's going to decay no matter what, so you either use the power or lose it.
I wonder if we'll ever see space technology advance enough so that, one day, we might be able to send a spacecraft past Voyager. Maybe we'll have some form of near-light-speed travel, or even faster-than-light travel, and manage to reach other stellar systems before Voyager does ?
In any case, I'll be more than satisfied if we establish a colony on Mars, tag me a conservative if you will, but I don't feel like leaving good old Sol just yet.
Maybe we deserve this world ?
I'm not sure why I'm bothering to respond to this obvious troll, but here goes...
We already have enough resources to take care of all the needy people not only in this country but on this planet. The real problem is that society, as a whole, just doesn't care enough about the unfortunates enough to do anything. If we were to stop sending any money on space exploration, that money would not get immediately diverted to persons in need. It would most likely end up funding tax breaks so that people can buy a new SUV. Or maybe it would "disappear" in a S&L fraud or HUD "misappropriation".
I grow tired of hearing people complaining that we should divert money from science towards needed social programs. Those programs are underfunded because we just haven't made them a priority. Slashing someone else's budget isn't going to make that money magically appear in the budget of social programs. We would need a real fundamental change in attitudes of elected officials and the voting public.
GMD
watch this
I worked at JPL for the power group, so I can actually say something about this. All of the deep-space probes run on radiothermal generators. What this is basically a radioactive source surrounded by thermoelectric generators and alpha particle absorbers. Thus, both the thermal gradient established between the radioactive material and space (via heat pipes and radiators) and the alpha particles emitted by the radioactive material are able to generate power. There are two limitations on the lifetime of these generators - the lifetime of the radioactive isotope, and the durability of the thermoelectrics and alpha particle absorbers. I don't know too much about the particle absorbers, but I worked with the thermoelectrics, and there are durability runs of several years. However, Voyager is far older then any test we could ever do. My feeling in this is that barring high-heat conditions, the thermoelectrics should be able to last nearly indefinitely.
For many years I was a co-investigator on Voyager (actually, technically, I suppose that I still am; I have never been notified that the status ever changed). Anyway, the best guess when I was an active participant, throughout the 80s and half of the 90s, was more-or-less the year 2010. That was predicted to be the year at which the always-decreasing power output from the transmitter, the ever-increasing distance and the more-or-less constant sensitivity of the DSN (Deep Space Network) system combined to reduce the received signal to the point where it the bit rate at which information could be extracted was too low to be useful.
The general supposition was that funding would be eliminated before that date.
...the right of the people to keep and arm bears shall not be infringed.
Voyager has been moving through space in ways unexplainable by physics. There is a small acceleration that can't be accounted for using known laws. It's almost like gravity doesn't work quite the way we think it does.
Of course, there is always the possibility that we just can't see the source of the acceleration, and it'll turn out to be something simple. However so far, all proposals put forth to explain it have been shown to be incorrect.
There is a deeper connection to very important issues in physics. For decades we have been studying the fabled "dark matter" which is supposed to be the cause of the anomalous rotation of the galaxy. The galaxy does not move in ways predicted by the laws of gravity. It is as if there is a huge amount of hidden mass which is influencing its rotation. So far we have not found any of this "dark matter."
But imagine the possibility. What if dark matter doesn't really exist? What if it's our understanding of gravity that is wrong? This would have profound implications throughout physics. After all our only direct experience of gravity is what happens here on Earth and within the bounds of the solar system. Except that today, we have a probe that has crossed that limit.
Perhaps the anomalous motion of Voyager will shed light on the situation. I for one would be utterly elated if it turns out we have to rewrite our physics books.
Voyager isn't useless yet!
Indeed, science can be distilled down to a set of little sound-bite facts that are easily repeatable. "There is no sound in space" is one of them. However what most people for some reason do not understand is that this is a SOUND BITE.
It is far too common for Slashdot readers to immediately object to something because it clashes with their boiled down kiddy version of science.
Here's some news for you: the space surrounding the sun is far from empty, in fact it is filled with atoms, electrons, and ionized gas. Its density is low enough that a human would not perceive it without an instrument. But sound can quite easily travel through gas, no matter how thin. Clearly the sound cannot travel any faster than the individual particles themselves are moving. Hence it is very easy to define the speed of sound in a gas.
No, I'm not claiming to be a scientist or above anyone else in terms of scientific knowledge, but it really pisses me off when people's first reaction is to DOUBT THE SCIENTISTS. Sure, they can be wrong sometimes, but I think it would be respectful to go do a little research before claiming, as if you are some kind of expert, that they are wrong.
There's no friction in space.
Oh, yeah? _You_ try sharing a battered smuggler ship with a flea-bitten wookie, a hillbilly brother/sister couple, an Alzheimer's patient with a light saber, and two gay robots.
(going from water to air is a speed increase, and I'm guessing its some function of density)
That's backward, sound travels much faster through water than through air. It does relate to density but not directly. The quantities that influence the speed of sound are the temperature and something called "bulk modulus" which describes how the material density changes as the pressure changes. Temperature is more important at very low densities. At higher densities as in solids the bulk modulus is the primary factor.
The spacecraft in question wasn't Voyager, but PIONEER 10. My point stands however, that having probes in the far reaches of space away from the solar system will be extremely valuable in the study of theories of gravity. Here's a link to a good place to start. A good Google search is "pioneer anomalous acceleration"
Near the end of the article I linked, they explain that this effect is not observed with Voyager because of the way Voyager is stabilized by boosters (as opposed to spin-stabilization for Pioneer). If the effect is occurring with Voyager it is completely swamped by the booster accelerations. They also indicate that (obviously) the best way to continue studying this is to launch another probe outside of the solar system.
If you spend any time researching this, you'll find groups of people all over the place who claim to have explained it. But none of them agree with each other. I think it's accurate to say that nobody REALLY knows what's happening.