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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?"

41 of 565 comments (clear)

  1. Agent Smith files for Chapter 11 by KFury · · Score: 5, Funny

    Do you guys have any idea how much RAM had to be added to the Matrix to extend the simulation out that far?!

    1. Re:Agent Smith files for Chapter 11 by temojen · · Score: 4, Funny

      A sparse matrix takes up a lot less memory.

    2. Re:Agent Smith files for Chapter 11 by KFury · · Score: 5, Funny

      "A sparse matrix takes up a lot less memory."

      A sparse matrix also makes a lot less money. Just ask theaters next week when the poor reviews outweigh the sequel buzz.

  2. Goodness... by swordboy · · Score: 5, Funny

    They've gone to plaid.

    --

    Life is the leading cause of death in America.
    1. Re:Goodness... by NanoGator · · Score: 4, Funny

      "Offtopic? Who the hell modded that off topic??? - Gone to plaid is a reference to ludricous speed taken from spaceballs."

      I'm surrounded by assholes!

      --
      "Derp de derp."
  3. Heliopause by Anonymous Coward · · Score: 5, Informative

    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.

  4. Of course we know what it will find by sielwolf · · Score: 3, Funny

    Aliens too stupid to wipe off some space dirt to realize the dang thing isn't named VEEEGERRRR!

    --
    What is music when you despise all sound?
  5. Even if it does, will it be able to tell us? by yndrd · · Score: 3, Interesting

    What's the range of communications for the probe? When will we lose our connection (if we haven't already)?

    1. Re:Even if it does, will it be able to tell us? by Carnildo · · Score: 3, Informative

      What's the range of communications for the probe? When will we lose our connection (if we haven't already)?

      No one knows for certain. A number of factors enter in, including the ability of Voyager to keep its antenna pointed at Earth, the amount of power left in the radiothermal generator, the size of radio telescope available for communicating with it on Earth, and possibly unknown effects from the heliopause.

      --
      "They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
    2. Re:Even if it does, will it be able to tell us? by leerpm · · Score: 4, Funny

      Yes, the US government has a secret message it uses to identify this point:

      "Can you hear me now? .. Can you hear me now?"

    3. Re:Even if it does, will it be able to tell us? by N7DR · · Score: 5, Informative
      What's the range of communications for the probe? When will we lose our connection (if we haven't already)?

      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.

    4. Re:Even if it does, will it be able to tell us? by Not_Wiggins · · Score: 3, Interesting

      I suppose if they felt they were still getting useful information from the probe (ie, it was "looking" at something "interesting" with sensors that still worked), they could always launch a relay-type satellite... just like a network repeater.

      Good thing they have several years to decide both if they:
      A) want to have/fund such a thing
      B) are getting new information worth collecting

      Heck... who knows where our terrestrial (or even space-stationed) receiver technology will be in 5 years; perhaps we'll be able to pick out the signal from here, no matter how weak nor how noisy.

      --
      Diplomacy is the art of saying, "Nice doggie!" until you can find a rock.
    5. Re:Even if it does, will it be able to tell us? by StewedSquirrel · · Score: 3, Interesting

      First of all, the primary issue with the signal falloff is the SIZE of the reciever. Launching a sattellite doesn't exactly solve that problem, because the sattelite's reciever would have to be *nearly* as large as the VLA or the big "lake sized" earth-bound dishes.

      I think it has more to do with the sheer size, than the sensitivity of the reciever. The "noise" from the Universe will eventually eat the signal and with the combination of decreasing power and increasing distance, I think xmit power will fall off faster than some "technology" (new filters, transforms, etc etc)

      Squirrel

      --
      There are 10 kinds of people in the world. Those who understand binary and those who don't.
    6. Re:Even if it does, will it be able to tell us? by gad_zuki! · · Score: 3, Funny

      >When will we lose our connection (if we haven't already)?

      Its good until 2005 when the FCC Broadcast Flag rule makes recieving the signal illegal without a DRM upgrade.

  6. Heliopause by mongoks · · Score: 4, Funny

    Voyager 1 has reached heliopause and is now experiencing hot flashes and irritability. Hormone replacement therapy has proven innefective thus far.

  7. The Heliosphere by UrgleHoth · · Score: 4, Informative

    NASA's page on the heliosphere

    --

    Dogma - "let's just say we'd like to avoid any empirical entanglements."
  8. Re:to paraphrase by Carnildo · · Score: 5, Interesting

    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.
  9. 12.5 Hours by johnos · · Score: 5, Interesting

    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.

    1. Re:12.5 Hours by CKW · · Score: 5, Interesting
      I love visualizing these things (all numbers approximate, I haven't pulled out the calculator.):

      if the galaxy was 100 KM wide,

      within 20 meters in any direction sun would be approximately 20 other stars,

      the nearest star would be 3-4 meters away,

      the probe would be 1.5 mm away.

      .

    2. Re:12.5 Hours by Have+Blue · · Score: 3, Insightful

      Don't forget the Yankee Stadium analogy: The sun is on home plate, the first 4 planets are between home and the pitcher's mound, Jupiter is on second base, Saturn and Uranus are in the outfield, Pluto is in the parking lot, and Centauri is in San Franciso.

    3. Re:12.5 Hours by Bingo+Foo · · Score: 3, Funny
      Pluto is in the parking lot,

      I hope someone at least left the window rolled down for him.

      --
      taken! (by Davidleeroth) Thanks Bingo Foo!
  10. The mind boggling nature... by downix · · Score: 3, Interesting

    of how scientists do not take the next big leap. What frightens me the most is that we have not sent more probes after Voyager.

    Coming up is a planetary alignment that would allow a route to Tau Ceti, one of the reasonably nearby stars that could have an inhabitable planet. Using modern high-velocity nuclear engines, a probe could be engineered to reach it in 100 years, roughly. And a craft could be engineered to actually survive the travel *and* send back useful data.

    I want to see interstellar probes, engineered to travel to the nearest (12ly or less) stars and explore them.

    --
    Karma Whoring for Fun and Profit.
  11. Re:you never know... by Major_Small · · Score: 3, Informative

    actually, kinda... it's the sound of a deep bass, which the human ear can't hear... they found out because they noticed it shifted planets and stars along it's wave... check it out here: space.com

  12. Voyager ~12 Light Hours away by _Sambo · · Score: 4, Informative

    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.

  13. Voyager's Last Message: by tjstork · · Score: 3, Funny


    says: "Doh, Stupid comet!"

    20 years from now, against all odds, the comet bashed ever so slightly by our irresponsibly launched space probe slams into Yellowstone super volcano.

    That little probe has to be stopped before it bumps into something! Send someone out to get it before it's too late!

    --
    This is my sig.
  14. Re:Fuel running out by BengalsUF · · Score: 5, Informative

    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.

  15. How long before we catch up with it ? by Jesrad · · Score: 4, Interesting

    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 ?
  16. Money isn't the problem by GuyMannDude · · Score: 4, Insightful

    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

    1. Re:Money isn't the problem by NanoGator · · Score: 4, Interesting

      "The real problem is that society, as a whole, just doesn't care enough about the unfortunates enough to do anything."

      Funny, when I read this, a memory bubbled to the surface. I was at a fast food joint one night. A homeless woman tapped my shoulder and asked for money to buy food. Thinking "hey, we're in a restaraunt, she'll actually use the money to buy food!" I gave her $5. She turned right around, wandered outside, and headed in the direction of a nearby shopping center complete with liquor store. The woman next to me in line was astonished. I wasn't terribly happy about that.

      Can't entirely blame society here. The whole 'teach a man to fish he can eat for a life time' story comes to mind. It's hard to buy a homeless guy a meal and let him go off to bum a meal off of somebody else the next day. I can give him my money, but what will he do to help himself?

      Society's not generally being cold hearted here. They are, however, closing themselves off from being taken advantage of. I don't have a solution to the homeless problem, but I'm reasonably confident that feeding them isn't the answer. They need to be made independent. Show me a way I can contribute to that, and I'm all ears.

      Don't assume people don't care. They do care. The problem is the solution isn't there.

      --
      "Derp de derp."
  17. Re:communicating? by Elwood+P+Dowd · · Score: 3, Informative

    The fuel is for communicating, not for moving.

    There's no friction in space. It can travel forever in its current direction. When the fuel runs out in 2020, we won't be able to hear from it.

    --

    There are no trails. There are no trees out here.
  18. RTGs by HermesHuang · · Score: 5, Informative

    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.

  19. Speed of Sound in Space by Rasta+Prefect · · Score: 3, Funny
    In space, the violent encounter slows the solar wind from supersonic velocity to subsonic speed, and causes a pileup of particles.

    Last time I checked the speed of sound in space was essentially zero...

    --
    Why?
    1. Re:Speed of Sound in Space by pclminion · · Score: 4, Insightful
      Sorry but this is a pet peeve of mine.

      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.

    2. Re:Speed of Sound in Space by pclminion · · Score: 4, Informative
      In a sparse gas where interparticle interactions are uncommon (they don't hit each other frequently), the speed of sound depends only on temperature and not density.

      (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.

  20. What if.... by jgacad · · Score: 4, Funny
    the aliens that find voyager only have CD players? How will they play the record that strapped to the craft?

    --
    ...the right of the people to keep and arm bears shall not be infringed.
  21. Re:to paraphrase by pclminion · · Score: 5, Interesting
    Better answer: We really hope so!

    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!

  22. 17 years later.. by Cassanova · · Score: 3, Funny

    Voyager crash lands on this deep and remote planet..as each of its systems start to shutdown in turn, its external microphones pick up the voice of Charleston Heston, screaming in the distance "Take your paws off me you damn dirty ape!"....
    [muffled horse hooves pounding on the ground]
    Voyager 1 signing off. Goodbye earth...
    ;-)

  23. Re:to paraphrase by Daniel_Staal · · Score: 3, Insightful

    Two reasons:

    1. Voyager is now mostly past the 'comets and stuff'.

    2. Getting useful information about space from telemetry means you have to track an object which you know the properties of. We know approximate mass for most comets. We know exact mass, composition, initial velocity, acceleration vectors and more about Voyager. This means we don't have to guess these in calculations, which means we get quite a bit more detailed info out of them.

    --
    'Sensible' is a curse word.
  24. Re:communicating? by Anonymous Coward · · Score: 4, Funny

    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.

  25. Re:Before revising theories of gravity ... by pclminion · · Score: 4, Informative
    Don't I feel stupid.

    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.

  26. Re:to paraphrase by Progman3K · · Score: 3, Insightful

    According to Wikipedia, you're right; Oort Clouds are postulated to extend 50,000-100,000 AU from their stars.

    That would effectively put Voyager outside the heliopause but still within Sol's Oort cloud.

    I like the end of the Wikipedia article:

    It is thought that other stars are likely to possess Oort clouds of their own, and that the outer edges of two nearby stars' Oort clouds may sometimes overlap, causing the occasional intrusion of a comet into the inner solar system.

    The reason I find this significant is that I remember hearing that it is believed some comets might be the ferriers of organic material, life even, from other stars and solar systems, and they may even be what seeded life here, in this solar system.

    So I hope they scrubbed down Voyager properly before launching it, otherwise countless years from now, it could crash-land on a planet somewhere and the microbes it is carrying (if they survived the trip) might

    - Have no effect
    - Seed life on a world
    - Cause a plague that kills all indiginous life on another planet because their immune systems are unable to cope with the microbes.

    Which do you think will happen?
    I'm taking bets.

    --
    I don't know the meaning of the word 'don't' - J