Voyager: at edge of our solar system

[Naty1]

Still going after 36 years.

Voyager surfs Solar System's edge
By Jonathan Amos
Science correspondent, BBC News

http://www.bbc.co.uk/news/science-environment-23075332

 

[Mordred]

it would be interesting to see just where our solar system stops, The older thought of boundary was shown different by voyager.

 

[Dotini]

Discovering the limits and properties of the sun's heliosphere seems to be an interesting if puzzling experience for the scientists involved. I would like to know if what they are finding about our own star would likely apply generally to other stars of similar size and type?

http://www.wired.com/wiredscience/2013/06/voyager-unexpected-region/

Scientists initially thought that Voyager’s transition into this new realm, where effects from the rest of the galaxy become more pronounced, would be gradual and unexciting. But it’s proven to be far more complicated than anything researchers had imagined, with the spacecraft now encountering a strange region that scientists are struggling to make sense of.

“The models that have been thought to predict what should happen are all incorrect,” said physicist Stamatios Krimigis of the Johns Hopkins University Applied Physics Laboratory, who is lead author of one of three new papers on Voyager appearing in Science on June 27. “We essentially have absolutely no reliable roadmap of what to expect at this point.”

The sun produces a plasma of charged particles called the solar wind, which get blown supersonically from its atmosphere at more than 1 million km/h. Some of these ions are thrown outward by as much as 10 percent the speed of light. These particles also carry the solar magnetic field.

Eventually, this wind is thought to hit the interstellar medium – a completely different flow of particles expelled from the deadly explosions of massive stars. The extremely energetic ions created in these bursts are known as galactic cosmic rays and they are mostly blocked from coming into the solar system by the solar wind. The galaxy also has its own magnetic field, which is thought to be at a significant angle to the sun’s field.

Researchers know that Voyager 1 entered the edge of the solar wind in 2003, when the spacecraft ’s instruments indicated that particles around it were moving subsonically, having slowed down after traveling far from the sun. Then, about a year ago, everything got really quiet around the probe. Voyager 1’s instruments indicated at the solar wind suddenly dropped by a factor of 1,000, to the point where it was virtually undetectable. This transition happened extremely fast, taking roughly a few days.

At the same time, the measurements of galactic cosmic rays increased significantly, which would be “just as we expected if we were outside the solar wind,” said physicist Ed Stone of Caltech, Voyager’s project scientist and lead author of one of the Science papers. It looked almost as if Voyager 1 had left the sun’s influence.

So what’s the problem? Well, if the solar wind was completely gone, galactic cosmic rays should be streaming in from all directions. Instead, Voyager found them coming preferentially from one direction. Furthermore, even though the solar particles had dropped off, the probe hasn’t measured any real change in the magnetic fields around it. That’s hard to explain because the galaxy’s magnetic field is thought to be inclined 60 degrees from the sun’s field.

No one is entirely sure what’s going on.

 

[Leeboy]

But that is the really cool thing about it, all the same, is that we managed to get something working that far out and still obtain useful data concerning what things are like out there!

My take on what was presented in the article is that Voyager might now be passing through the true bow shock wave. The solar particles piling up & deflecting with the voyager plowing through it (and maybe noticing what the interstellar medium is going to be like).

 

[solar71]

Oh wow This is cool. I always thought the edge of our solar system was the Oort Cloud. Is this past that point or is it still coming? Also how in the world do they make a battery last 36 years? I know they said Plutonium but is it a reactor or a battery? How do you make a battery out of Plutonium?

 

[Drakkith]

Oh wow This is cool. I always thought the edge of our solar system was the Oort Cloud. Is this past that point or is it still coming?

It's pretty much up for debate. You could classify it as the oort cloud, but that's WAAAAY out there at around 1 light year I think. Voyager 1 is nowhere near it yet and won't be for a very very long time.

Also how in the world do they make a battery last 36 years? I know they said Plutonium but is it a reactor or a battery? How do you make a battery out of Plutonium?

It's not a battery, it's a radioisotope thermoelectric generator. They basically just let a couple of big blocks or pellets of plutonium sit there and decay. The natural decay process heats the block of plutonium up to several hundred degrees. There's a thermocouple connected to a heat sink that uses the heat generated by the plutonium to generate electricity, with the wasted heat radiated off into space via the heat exchangers in the heat sink.

http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

Due to loss of plutonium from the decay, along with aging of the thermocouple and other components, the power from the RTG's on each Voyager spacecraft has dropped to about 60% what it was at launch.

 

[Dotini]

I always thought the edge of our solar system was the Oort Cloud.

The Oort cloud has been hypothesized but never confirmed or observed. It is a great convenience to explain the source of long period comets.
http://en.wikipedia.org/wiki/Oort_cloud

 

[Astrolekker]

Is it possible that Voyager could continue to function until it reaches the next star?

The Oort cloud has been hypothesized but never confirmed or observed. It is a great convenience to explain the source of long period comets.
http://en.wikipedia.org/wiki/Oort_cloud

It would also explain how Neptune and Uranus have their moons.

 

[Mordred]

Is it possible that Voyager could continue to function until it reaches the next star?

lol not likely the speed of the probe is approximately 17 km/sec, the nearest star other than our sun is 4.2 light years away. So at that speed it would take roughly 70,588 years to arrive.

assuming the travel speed from this link is correct and Voyager can maintain its currect speed.


http://en.wikipedia.org/wiki/Voyager_1

edit forgot to calculate number of sec per year lol the above is only how long voyager would travel 4 light seconds also forgot to handle the travel per year for Voyager.

the corrected value is 17,647 years

 

[Astrolekker]

lol not likely the speed of the probe is approximately 17 km/sec, the nearest star other than our sun is 4.2 light years away. So at that speed it would take roughly 70,588 years to arrive.

assuming the travel speed from this link is correct and Voyager can maintain its currect speed.


http://en.wikipedia.org/wiki/Voyager_1

edit forgot to calculate number of sec per year lol the above is only how long voyager would travel 4 light seconds also forgot to handle the travel per year for Voyager.

the corrected value is 17,647 years

I knew it was a long time such as that.

It could be possible if nothing disturbed it, the plutonium contained inside it should decay long enough. Plus with just a vacuum around it, nothing can rot it away etc..

 

[Mordred]

Unfortunately no, from what I can tell from the link MFB provided they used a plutonium 238 pellet. That has a half life of 88 years

 

[StrayCatalyst]

The generators will be useless pretty soon - at least inside of the next 20 years or so. The half life of the isotopes is part of the problem, but the thermocouples are also losing efficiency due to age. Eventually it will reach the point that the isotope's generated heat won't be enough to provide enough power to the aging thermocouples, to continue running Voyager's systems. Voyager itself will continue, of course - but by the time it reaches the next star system, the human race may be extinct.

 

[collinsmark]

Hee hee.

Voyager 1

[source: http://xkcd.com/1189/]

With mouseover:

So far Voyager 1 'left the Solar System'; by passing through the termination shock three times, the heliopause twice, and once each through the heliosheath, heliosphere, heliodrome, auroral discontinuity, Heaviside layer, trans-Neptunian panic zone, magnetogap, US Census Bureau Solar System statistical boundary, Kuiper gauntlet, Oort void, and crystal sphere holding the fixed stars.​

 

[RobinSky]

The Oort cloud has been hypothesized but never confirmed or observed. It is a great convenience to explain the source of long period comets.
http://en.wikipedia.org/wiki/Oort_cloud

Cool! Didn't know that!

Thanks

/Robin

 

[Greg Bernhardt]

Apparently it just exited our solar system!
http://www.cnn.com/2013/09/12/tech/innovation/voyager-solar-system/index.html?hpt=hp_t1

scientists now have strong evidence that NASA's Voyager 1 probe has crossed this important border, making history as the first human-made object to leave the heliosphere, the magnetic boundary separating the solar system's sun, planets and solar wind from the rest of the galax

 

[Drakkith]

Apparently it just exited our solar system!
http://www.cnn.com/2013/09/12/tech/innovation/voyager-solar-system/index.html?hpt=hp_t1

Wooo! Go Voyager 1!

 

[Naty1]

yes, I saw that news on TV just as few minutes ago.

The lead scientist said istrumentation is being gradually turned off to conserve power and all systems will be shut down around 2025...and Voyager will orbit our solar system from then on.
I did not quite understand that last part.

 

[BobG]

Apparently it just exited our solar system!
http://www.cnn.com/2013/09/12/tech/innovation/voyager-solar-system/index.html?hpt=hp_t1

Depends how you define the solar system.

Voyager 1 has just entered interstellar space. That's a description of its environment.

If you consider the Oort cloud to be part of the solar system (objects in interstellar space that still orbit the Sun), then Voyager 1 still has a ways to go.

But, entering interstellar space is still a huge deal...

... and a good time to listen to the Voyager's Golden Record: Voyager Golden Record

It looks like they've even reprinted the book about the making of the Golden Record: Murmers from Earth: The Voyager Interstellar Record

I have the original hardcopy version of the book and its pretty fascinating - especially the chapter on trying to figure out how to format a message that some unknown alien race might actually understand.

 

[nsaspook]

... and a good time to listen to the Voyager's Golden Record: Voyager Golden Record

Lets hope whatever alien race finds the record rocks!

Go Voyager go!

 

[the_wolfman]

Apparently it just exited our solar system!
http://www.cnn.com/2013/09/12/tech/i...html?hpt=hp_t1

To be clear, NASA is saying that they now agree that Voyager entered interstellar space a year ago.

 

[Dotini]

Some of the surprising discoveries worth more explanation:

- The direction of the interstellar magnetic field differed by only about 2 degrees from that of the heliosphere.
- The density of the interstellar plasma is considerably greater than that of the heliosphere.
- Interstellar particles seem to coming in preferentially from certain directions, and not randomly.

 

[lpetrich]

yes, I saw that news on TV just as few minutes ago.

The lead scientist said istrumentation is being gradually turned off to conserve power and all systems will be shut down around 2025...and Voyager will orbit our solar system from then on.
I did not quite understand that last part.

Seems like a mistake somewhere. The Voyager spacecraft will keep on going away from the Sun, and they will orbit our Galaxy's center in separate orbits.

 

[MathJakob]

I get this strange feeling when I think about voyager. Just glance out your window and just to think that 12billion miles away is something that is made by man, for every second that passes it gets over 10 miles further away. Yet we just go about our daily lives forgetting for the most part, but voyager 1 doesn't forget, it continues on it's journey into the darkness.

It's quite funny though that if you send a photon, it would catch upto voyager 1 in just 18 hours lol.

It's quite a weird feeling to think that voyager 1 will never return, my stomach turns a little when I think what it feel like to be on that probe, knowing that you can never return... It's one of the reason I won't sign upto Mars1. Although it probably won't even happen anyway.

 

[Drakkith]

No worries. Voyager 1 has no feelings! It can't get lonely as it looks back on us, so far away that it can't even see us in a picture. Less than the size of a pixel...

Crap I feel so small now...

 

[MathJakob]

No worries. Voyager 1 has no feelings! It can't get lonely as it looks back on us, so far away that it can't even see us in a picture. Less than the size of a pixel...

Crap I feel so small now...

I just wish the world would wake up a realize that there is so much more to the universe than humanity and earth. I just hope I am alive the day we can confirm that we are not alone. Cmon aliens! Make yourselves known!

 

[Naty1]

Hawking, for one, was very uneasy that we gave directions for finding us emblazoned on Voyager.

I hope his concerns are unfounded.

 

[Drakkith]

Hawking, for one, was very uneasy that we gave directions for finding us emblazoned on Voyager.

I hope his concerns are unfounded.

Meh, I'm not very concerned. That thing takes so long to get anywhere that it pretty much doesn't matter.

 

[Naty1]

That thing takes so long to get anywhere that it pretty much doesn't matter.

but it's signals travel at the speed of light.

Interesting note on Voyager computer memory:

Although it's traveled 11.6 billion miles to interstellar space, Voyager 1's software isn't as high-tech as you may think. In fact, it has less than 40 KB of memory. To put that in perspective, your 16 GB iPhone 5 has about 240,000 times the memory of a Voyager spacecraft .

http://mashable.com/2013/09/12/voyager-1-iphone-5/

Voyager has three interconnected computer systems: one to control the craft’s flight and altitude, another to control its instruments, and a third to manage the first two. The computers can process about 8,000 instructions per second -- a fraction of the capability of your smartphone, which handles upwards of 14 billion each second.

http://www.washingtonpost.com/blogs...-using-less-computing-power-than-your-iphone/

Any aliens that discover Voyager might think us retards!

 

[MathJakob]

Any aliens that discover Voyager might think us retards!

Any aliens capable of understanding what Voyager 1 is would know that this probe has been traveling for potentially hundreds of thousands of years and so one would expect dated technology. On the flip side our probe could be on it's way to a planet which hasn't even devloped life yet and once it arrives in say 100million years, life could have developed and suddenly 40kb of memory on a circuit board makes us seem like the smart dudes :P

Could you imagine if we ever receive an alien probe similar to voyager it could be extremely sophisticated, much beyond our current understanding and to us it would seem like crazy sci-fi technology who knows... and the aliens current technology has long surpassed that which their probe is carrying.

 

[Drakkith]

but it's signals travel at the speed of light.

Yeah, but they are weak and are aimed back at us, not out into space in the direction it's heading. Plus it won't be transmitting for much longer. Another decade or so at the most.

 

[lpetrich]

There are two reasons that the Voyagers' computers are so puny.

• When they were designed and built - the mid 1970's.
• The necessity of being hardened against ionizing radiation.

Rad-hard chips are always some years behind their civilian counterparts. Consider What Powers the Mars Curiosity Rover? | News & Opinion | PCMag.com
That rover has a 200-MHz CPU with 256-MB RAM, 256-MB EEPROM, and 2-GB flash memory.
Its CPU is a BAE RAD 750, a rad-hard version of the IBM 750 one (mid 1990's).

Its predecessors are the Spirit and Opportunity rovers, launched in 2003.
Each of them has a 20-MHz CPU with 128-MB RAM, 3-MB EEPROM, and 256-MB flash memory.
Their CPU's are an IBM RAD6000, a rad-hard version of the RISC Single Chip for IBM RS/6000 workstations (early 1990's).

RAD6000 chips have been used in numerous spacecraft , so these Mars rovers are not exceptional.