Voyager spacecrafts - 14 billion miles since 1977
Ron Czapala
Posts: 2,418
video: http://www.space.com/11518-voyager-humanity-farthest-journey.html
Milky Way Radiation Reveals Itself to Distant NASA Probes
Decades after NASA's Voyager spacecraft began hurtling toward interstellar space, the twin probes are still shedding light on the universe, now by offering an unprecedented view of our own galaxy.
As they roam ever outward to the edge of the solar system, the two Voyager spacecraft are providing the first glimpse of Milky Way radiation that scientists have already seen coming from other galaxies. The data could lead to a better understanding of star formation, including the mystery surrounding the earliest stars in the universe, researchers said.
NASA launched the two Voyager spacecraft in 1977 to explore our solar system's giant planets and to study the electrically charged solar wind streaming from the sun. The probes far exceeded the expectations of mission planners, and to this day, they continue to beam back data.
The Voyagers are now providing us with the first glimpse of a critical type of ultraviolet radiation from our galaxy known as the Lyman-alpha line. This is the brightest band of light shed by hydrogen, the most abundant element in the universe.
Studying the Lyman-alpha line can offer many insights into cosmic phenomena, such as star formation, the electrically charged environments in which the atmospheres of young planets evolve, and the shocked gas in interstellar space. [Photos from NASA's Voyager 1 and 2 Probes]
Astronomers have seen Lyman-alpha rays from other galaxies, helping them peer into the universe's early history. However, we have never seen ones from our own galaxy, because our sun essentially blinds our view.
Specifically, ultraviolet rays from our sun get scattered around by hydrogen entering our solar system from interstellar space. This leads to a haze that blinds us to Lyman-alpha rays from elsewhere in our galaxy. We can detect other galaxies' Lyman-alpha rays because they have shifted into longer optical and infrared wavelengths — ones that no longer get scattered by this hydrogen — as their galaxies rush away from us. This is similar to how ambulance sirens grow lower in pitch as the vehicle drives farther away.
Now Voyager 1 and 2 are far enough away from this ultraviolet haze for them to get a clear view of the Milky Way's Lyman-alpha rays.
"It is like beginning to see small candles within a brightly lit room," study lead author Rosine Lallement, a space scientist and astronomer at the Paris Observatory in Meudon, France, told SPACE.com.
The spacecraft have confirmed that most of these newfound rays appear to come from star-forming regions, as astronomers expected. Future study of the Milky Way's Lyman-alpha rays could help us better understand those from other galaxies, researchers added.
"This radiation traces where young hot stars are being born — therefore, knowing the amount of emitted Lyman-alpha radiation from a galaxy corresponds to the rate at which stars are being born," Lallement said. "A major goal is to detect the first apparition of stars in the young universe, so detecting Lyman-alpha from the most-distant ones and correctly interpreting the signal is one of the major challenges."
Ironically, just as the Voyager probes are getting their best views of these Milky Way rays, their ability to see them is failing. Due to lack of power, the ultraviolet spectrometer on Voyager 2 has been switched off, and that same instrument on Voyager 1 could get turned off soon as well.
Still, NASA's New Horizons spacecraft, which is currently on its way to Pluto, might soon be able to monitor these rays as well.
Lallement and her colleagues detailed their findings online in the Dec. 1 issue of the journal Science.
Milky Way Radiation Reveals Itself to Distant NASA Probes
Decades after NASA's Voyager spacecraft began hurtling toward interstellar space, the twin probes are still shedding light on the universe, now by offering an unprecedented view of our own galaxy.
As they roam ever outward to the edge of the solar system, the two Voyager spacecraft are providing the first glimpse of Milky Way radiation that scientists have already seen coming from other galaxies. The data could lead to a better understanding of star formation, including the mystery surrounding the earliest stars in the universe, researchers said.
NASA launched the two Voyager spacecraft in 1977 to explore our solar system's giant planets and to study the electrically charged solar wind streaming from the sun. The probes far exceeded the expectations of mission planners, and to this day, they continue to beam back data.
The Voyagers are now providing us with the first glimpse of a critical type of ultraviolet radiation from our galaxy known as the Lyman-alpha line. This is the brightest band of light shed by hydrogen, the most abundant element in the universe.
Studying the Lyman-alpha line can offer many insights into cosmic phenomena, such as star formation, the electrically charged environments in which the atmospheres of young planets evolve, and the shocked gas in interstellar space. [Photos from NASA's Voyager 1 and 2 Probes]
Astronomers have seen Lyman-alpha rays from other galaxies, helping them peer into the universe's early history. However, we have never seen ones from our own galaxy, because our sun essentially blinds our view.
Specifically, ultraviolet rays from our sun get scattered around by hydrogen entering our solar system from interstellar space. This leads to a haze that blinds us to Lyman-alpha rays from elsewhere in our galaxy. We can detect other galaxies' Lyman-alpha rays because they have shifted into longer optical and infrared wavelengths — ones that no longer get scattered by this hydrogen — as their galaxies rush away from us. This is similar to how ambulance sirens grow lower in pitch as the vehicle drives farther away.
Now Voyager 1 and 2 are far enough away from this ultraviolet haze for them to get a clear view of the Milky Way's Lyman-alpha rays.
"It is like beginning to see small candles within a brightly lit room," study lead author Rosine Lallement, a space scientist and astronomer at the Paris Observatory in Meudon, France, told SPACE.com.
The spacecraft have confirmed that most of these newfound rays appear to come from star-forming regions, as astronomers expected. Future study of the Milky Way's Lyman-alpha rays could help us better understand those from other galaxies, researchers added.
"This radiation traces where young hot stars are being born — therefore, knowing the amount of emitted Lyman-alpha radiation from a galaxy corresponds to the rate at which stars are being born," Lallement said. "A major goal is to detect the first apparition of stars in the young universe, so detecting Lyman-alpha from the most-distant ones and correctly interpreting the signal is one of the major challenges."
Ironically, just as the Voyager probes are getting their best views of these Milky Way rays, their ability to see them is failing. Due to lack of power, the ultraviolet spectrometer on Voyager 2 has been switched off, and that same instrument on Voyager 1 could get turned off soon as well.
Still, NASA's New Horizons spacecraft, which is currently on its way to Pluto, might soon be able to monitor these rays as well.
Lallement and her colleagues detailed their findings online in the Dec. 1 issue of the journal Science.
Comments
Hello!
Remember Ron we're talking about a 34 year gap in technology. The two of them share something in common with the now finished Viking missions to Mars. Heck even the two on Mars now are advanced examples.
The two of them turned out amazing insight into how our solar system was created. (Yes Gordon I hear you, "Six years late and over budget as well!".) They also turned out amazing insight into everything else. Look what happened when the Pioneer twins left the solar system. Eleven actually was sent the shutdown command because it was still sending out information at the extreme edge of things.
Everything we do out there is a testament of some kind to the incredible talents that everyone here has. However I am eagerly awaiting the first views delivered by the MESL mission, and he just left here for Mars......
BTW the computers on these spacecraft are way less than an Apple. IIRC 4KB of memory and a tape drive.
As I recall, each craft had a plaque bolted to its side, reading: "This is just an itsy-bitsy, teeny-weenie, tiny little example of what humans could achieve... when they weren't watching TV, fighting and dying over barrels of oil, sitting in traffic, or playing Pong."
ILIA PROBE: To find the Creator.
KIRK: To find the Creator? Whose? ...What does V'Ger want with the Creator?
ILIA PROBE: To join with him.
SPOCK: Join with the Creator? ...How?
ILIA PROBE: V'Ger and the Creator will become one.
SPOCK: And who is the Creator?
ILIA PROBE: The Creator is that which created V'Ger.
KIRK: Who is V'Ger?
ILIA PROBE: V'Ger is that which seeks the Creator."
Come on, you knew somebody was going to do it!
It takes about 8 hours for a signal to get to Voyager (at the speed of light). It has taken Voyager 33 years to get this far, being 8 light hours.
Q: The closest star, Proxima Centauri is about 4.2 light years away. If it takes Voyager 33 years to go 8 light hours, how long would it take to get to the Proxima Centauri?
A: = (4.2 * 365.25 * 24 / 8) * 33 years
= ~4602 * 33 years
= ~151,866 years
Do you think maybe that's a big place up there???
If we can measure it after just two trips around the Earth, I wonder what the time dilation is of the Voyager is after 33 years.
...
Our galaxy itself contains a hundred billion stars.
It's a hundred thousand light years side to side.
It bulges in the middle, sixteen thousand light years thick,
But out by us, it's just three thousand light years wide.
...
What really bakes my brain is that current accepted science thinks that radio signals are electrons that can maintain the information over that vast distance. My vote is still for a space medium that can carry information, not electrons that are supposed to weaken and expand their area of coverage as they travel. Comments?
Radio signals, gamma rays, X-rays, light, they're all one and the same: Electromagnetic fields, just with different energy levels. Think photons, not electrons.
-Tor
Current theory dictates that a radio signal is generated by electronics. Whatever circuit you use is used to excite electrons into a frequency on a transmission medium (antennae). This induces the EMF which propogates out from the transmission. Do we agree at this point?
If so, then to picture what you are saying appears to require a space medium. In order for any quanta of energy to be "carried" anywhere, there must be a carrier. Just like light traveling through space; if you do not use the physical photon as the carrier of light and you also use the emag field, then there must be something that allows the field to propogate. To say it guides itself, is self aware and knows what is doing at all times along it's path does not make as much sense as there being a path preset that is ready for it's initial motivation/direction.
Regarding the "ruled out" part of medium, there are still many (mostly Christian Scientists from what I have seen) that still believe there is a space medium. My college Physics Emag professor believed in a space medium. Just because you can't measure it doesn't mean it doesn't exist. And there are still experiments being conducted to investigate the effects of a space medium (also called "drag" on the space-time frame, ring a bell?).
And, speed of light is not the same in all directions, that is how we get red shift in looking at other galaxies. I understand you mean "the law" as the speed of light, but I am looking at the effects. I could also argue , "what makes the law?....a carrier".
I understand there are just as many arguements against the space medium, for example, if there is a frequency being carried with all of this other signal junk in space, then how can you ever get a single signal anywhere. Still it seems to me with our knowledge of signal theory that would be explainable, as you can carry multiple signals on a single carrier.
And, add that to the fact that there are signal black outs due to physical objects. If emag propogation was really some all powerful force that did not require any medium then it is reasonable that is should not be affected by physical objects, then we should have no signal black outs. Again, you could argue that if there was a space medium, then the signal should also avoid black outs.
I mean really, everything else in the universe has a carrier (sound, electronics signals, light) that can guide them and shape them. There are different types of carriers....water, plastic and glass can all carry light and affect it differently.
To be so adamant about what is being tought as being the "right" way, is very close minded I think. Anytime to follow a rule, you lose sight of another option.
Space and Time or 'spacetime" is a funny concept ... Light (or radio waves) traveling in space are not just traveling in space, but traveling in spacetime but because they are traveling at the speed of light, the light or Electromagnetic energy itself is said to be 'timeless'.
Reference this at about 2:50 ... http://www.youtube.com/watch?v=xvZfx7iwq94&NR=1
I fail to see why there has to be a 'must' in there. A pre-set path seems to me to open up a Pandora's box of problems. Note that I'm not a physicist, just a layman, and also my English is not good enough to even try to write down a good explanation of EMF propagation. My understanding though is that the two components of the electromagnetic field reinforce and keep each other running. (Found an animation btw: http://en.wikipedia.org/wiki/Electromagnetic_radiation) Presumably a medium would just instead sap out the energy and you would lose the field quickly, instead of what we actually observe.
When I said ruled out, I was referring to the MichelsonMorley experiment. It truly didn't observe any directional effect on light speed. This isn't the same as searching for a missing animal and saying you can't rule it out just because you didn't find it: If there had been an aether medium which light, or emf, propagates through, then it should also be affected by how the earth moves through the aether. No such effect was found then, and no such effect has been found since, and what came out of it was special relativity. It seems to me that if anyone chooses to 'believe' in an aether then they're also ruling out special relativity.. and of course, the easiest way to move forward in science is often to disprove a theory instead of proving it. So that's what almost every scientist tries to do: Figure out a new test, hammer on the hypothesis from all directions and try to break it. Check if the hypothesis predicts some effect that a competing hypothesis doesn't predict, and see if the prediction is correct. Do all of this for a while and if the hypothesis still holds it changes to be a theory. And that's where special relativity is right now, so I think it takes more than just choosing to not believe in it to disregard it. Of course it would be fun if special relativity _could_ be shown to be wrong, or at least not the whole story (as Newtonian mechanics was shown not to be wrong, but not to be the whole story). New physics is always very exiting.
But frame dragging doesn't have anything to do with drag on a supposed space medium. Frame dragging is about space itself, or, rather, space-time.
Whoa there.. red shift doesn't have anything to do with direction, it has everything to do with distance and space expansion. Red shift, and absolutely everything else looks exactly the same in every direction you look at. This observation is one of the corner stones behind the current theory about what happened after the Big Bang, specifically inflation theory (this does not mean that inflation has to be the right theory, but it fits the facts and observations so far). To me involving a carrier makes things awfully complicated, it adds a lot of problems (and crashing heads-on with the MichelsonMorley experiment and others like it). A carrier solution simply creates much more trouble than it solves, in my opinion.
Electromagnetic fields are of course affected by physical objects, that's no argument for or against an aether. There are four known fundamental forces: Electromagnetism, the strong nuclear force, the weak nuclear force, and gravity (unless you choose to think of gravity purely as a geometrical effect on spacetime, not just as a way of describing general relativity but in a real sense as well). The forces are affected by the particles of physics in different ways. As we know electromagnetism is definitely affected by matter, in particular matter with free electrons, like metals and semiconductors. That's the reason we have this Parallax forum, for example.. and radio receivers. Everything, really.
I can only say that to me the close-mindedness is in only being able to think of propagation as something that can only be working through a physical medium (like wood, or an aether). Sound isn't at all like light, so why do they have to propagate the same way?
-Tor