What is really amazing is that the probe still operates after over 3 decades, which is a testament to the design team. It’s a SNAP to keep powered up though. – Anthony
Artist concept of Voyager near interstellar space. Image credit: NASA/JPL
From NASA JPL: (h/t to Dr. Leif Svalgaard)
PASADENA, Calif. – The 33-year odyssey of NASA’s Voyager 1 spacecraft has reached a distant point at the edge of our solar system where there is no outward motion of solar wind.
Now hurtling toward interstellar space some 17.4 billion kilometers (10.8 billion miles) from the sun, Voyager 1 has crossed into an area where the velocity of the hot ionized gas, or plasma, emanating directly outward from the sun has slowed to zero. Scientists suspect the solar wind has been turned sideways by the pressure from the interstellar wind in the region between stars.
The event is a major milestone in Voyager 1’s passage through the heliosheath, the turbulent outer shell of the sun’s sphere of influence, and the spacecraft’s upcoming departure from our solar system.
“The solar wind has turned the corner,” said Ed Stone, Voyager project scientist based at the California Institute of Technology in Pasadena, Calif. “Voyager 1 is getting close to interstellar space.”
Our sun gives off a stream of charged particles that form a bubble known as the heliosphere around our solar system. The solar wind travels at supersonic speed until it crosses a shockwave called the termination shock. At this point, the solar wind dramatically slows down and heats up in the heliosheath.
Launched on Sept. 5, 1977, Voyager 1 crossed the termination shock in December 2004 into the heliosheath. Scientists have used data from Voyager 1’s Low-Energy Charged Particle Instrument to deduce the solar wind’s velocity. When the speed of the charged particles hitting the outward face of Voyager 1 matched the spacecraft’s speed, researchers knew that the net outward speed of the solar wind was zero. This occurred in June, when Voyager 1 was about 17 billion kilometers (10.6 billion miles) from the sun.
Because the velocities can fluctuate, scientists watched four more monthly readings before they were convinced the solar wind’s outward speed actually had slowed to zero. Analysis of the data shows the velocity of the solar wind has steadily slowed at a rate of about 20 kilometers per second each year (45,000 mph each year) since August 2007, when the solar wind was speeding outward at about 60 kilometers per second (130,000 mph). The outward speed has remained at zero since June.
The results were presented today at the American Geophysical Union meeting in San Francisco.
“When I realized that we were getting solid zeroes, I was amazed,” said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and senior staff scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Here was Voyager, a spacecraft that has been a workhorse for 33 years, showing us something completely new again.”
Scientists believe Voyager 1 has not crossed the heliosheath into interstellar space. Crossing into interstellar space would mean a sudden drop in the density of hot particles and an increase in the density of cold particles. Scientists are putting the data into their models of the heliosphere’s structure and should be able to better estimate when Voyager 1 will reach interstellar space. Researchers currently estimate Voyager 1 will cross that frontier in about four years.
“In science, there is nothing like a reality check to shake things up, and Voyager 1 provided that with hard facts,” said Tom Krimigis, principal investigator on the Low-Energy Charged Particle Instrument, who is based at the Applied Physics Laboratory and the Academy of Athens, Greece. “Once again, we face the predicament of redoing our models.”
A sister spacecraft, Voyager 2, was launched in Aug. 20, 1977 and has reached a position 14.2 billion kilometers (8.8 billion miles) from the sun. Both spacecraft have been traveling along different trajectories and at different speeds. Voyager 1 is traveling faster, at a speed of about 17 kilometers per second (38,000 mph), compared to Voyager 2’s velocity of 15 kilometers per second (35,000 mph). In the next few years, scientists expect Voyager 2 to encounter the same kind of phenomenon as Voyager 1.
The Voyagers were built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft. For more information about the Voyager spacecraft, visit: http://www.nasa.gov/voyager . JPL is a division of the California Institute of Technology in Pasadena.
It’s just like so far out there man……
Seriously, this is one of the greatest successes of science; and also a strong endorsement of nuclear power.
I think it’s cool that the Voyagers are still reporting back. However, I don’t get the same sense of awe as others do as to how far it’s gone. Sure, it’s amazing and all. To me, it’s more how humans tend to give up when faced with insurmountable challenges. Yet, we look at the vastness of space and it has the exact opposite effect. We see possibilities. Humanity will never give up its quest to reach the stars. Voyager (quite appropriately named) is more about the first steps in that long journey, as was the case with going to the moon. It is humanity taking those steps whether physically or not. In the future, when we look back, the Moon mission and Voyager will always be in the history books and a reminder to future generations of our determination. I think we need that reminder today more than ever.
My part of these vehicles was as chief engineer of the large Stage I solid rocket motors which gave them their first motion from the pad at the Cape. So many miles and so many years lay ahead of them and it’s not over yet. It sort of boggles the mind to reflect that we have more computing power in our iPhones than was available to us in the design and launch of these V’gers.
I can’t wait for the Klingons to lay a tractor beam on one of these and bring it on board. They will marvel at the gold LP record with a message from Nixon giving greetings from Earth and deciding that wiping out the blue planet wouldn’t be worth the effort after all. I hope the next time we take on a mission like this (fat chance) we can do as well as the guys at JPL did with the Voyager payload.
/Reminiscence. Back to work.
@ur momisugly Mike Borgelt
Regarding Space X, I completely agree. I have followed them with great interest. A well run company, but they are still up against physics and biology. You gotta start somewhere though. I’m in the stands cheering them on. Wish I was on the team….timing is everything.
@ur momisugly Jimash:
>Shouldn’t there be something between chemical rockets and flux-capacitor warp drives ?
If you find it, let me know.
Regg_upnorth says:
December 14, 2010 at 5:04 pm
Well of course it is still operating, it’s not running on fossils fuel. Electric power with radioactive generator.
This is hardly the point. The electronics 33 years ago were not hardened like they are today. For the Voyager’s to be still communicating is a matter of excellent design. You could have all the power of the universe, but if the electronics are degraded to the point of failure, there is nothing to show for it. Solar/cosmic radiation is an electronics killer. Now that it is on edge where cosmic radiation is even more damaging, if the Voyager’s continue to communicate, even more the amazement.
1977, same year Star Wars came out. I was 15. Went and saw it 13 times at the theater.
Looking for that unique gift for that special person? I highly recommend:
Voyager: Seeking Newer Worlds in the Third Great Age of Discovery, by historian Stephen J. Pyne (Viking Press 2010)
available at Amazon and your best book stores. Those seeking a space adventure and nothing more will be surprised and possibly confused by this book because it is so much more than that. The story of Voyager, from early conception to launch to the gravity assist past the outer planets to the heliosheath is in there, but so is an exploration of exploration itself, the history and motivations for societal investment in seeking new worlds, whether they are distant planets, deep sea rift zones, or new continents. All graced by Pyne’s remarkable and delightful gift for prose.
A soundbite that should be looped into a song for climate science-fiction artists:
“Once again, we face the predicament of redoing our models.”
“Once again, we face the predicament of redoing our models.”
“Once again, we face the predicament of redoing our models.”
…
I acknowledge that it is hard work, but sometimes pay needs to be earned.
Leif Svalgaard says:
December 14, 2010 at 7:07 pm
This would mean that the spacecraft is now ploughing into the wind at 17 km/s. So, the interpretation of a sideways deflection seems to be reasonable. If so, the solar wind has been slowed by interaction with the interstellar medium, and is no longer just coasting outward. The particles cannot return to the Sun as they will be picked up by the outflow if they moved closer. The solar wind keeps both its own debris and interstellar ions at bay.
Hi Leif. Would voyager know if the local particle density was increasing? I ask because logically, if the particles from the solar wind stop moving outwards, and they can’t go inwards as you insist the solar wind will blow them out again, then they must surely accumulate at the boundary with the heliosheath.
Leif Svalgaard says:
December 14, 2010 at 7:07 pm
So, the interpretation of a sideways deflection seems to be reasonable. If so, the solar wind has been slowed by interaction with the interstellar medium, and is no longer just coasting outward. The solar wind keeps both its own debris and interstellar ions at bay.
Sideway deflection or perpendicular, same thing.
There is no escape for charge particles.
What then?
The particles cannot return to the Sun as they will be picked up by the outflow if they moved closer.
This must be wrong.
1. Electrons combine with the incoming galactic ions, creating ENAs as observed by IBEX
http://science.nasa.gov/media/medialibrary/2010/01/14/15jan_ibex2_resources/model.jpg
2. Protons are either accumulating there for billions of years, creating permanent ever increasing proton cloud ? , not likely, nothing like that has been found or observed. No electronic device would survive such radiation and the Voyager would be doomed.
I suggest, protons slow down, turn around along inner boundary of heliosphere and head ‘home’, outside the helio-sheet
http://solar-heliospheric.engin.umich.edu/images/CurrentSheet2%5B1%5D.jpg
pulled back by the sun’s gravitation, eventually spiralling into the sun’s at the high latitudes.
Monty says:
December 14, 2010 at 8:53 pm
@ur momisugly Jimash:
“>Shouldn’t there be something between chemical rockets and flux-capacitor warp drives ?
If you find it, let me know.”
I’ am not sure what a flux-capacitor warp drive is or does. But as for a true space drive I am working on it. pg
This is one of those ‘WOW!’ moments filled with the awe and wonder that good educators try to provide kids with from time to time.
Thanks for this, Anthony.
Dr. L.S
The solar particles left the Sun with a speed higher than the escape velocity and will therefore never return to the Sun [and surely not ‘at higher latitudes’ – what makes them go up there?.
Escape velocity from the sun (a year earlier) is nothing to do with it if protons eventually slow down.
What makes them go up there?.
Simple physics. On many occasions you quoted garden sprinkler as an analogy of solar wind.
To elaborate further: I suggest use your garden hose and point jet of water (solar wind) at the garden wall (heliosheath) and see the analogous effect. Water droplets do not come back into the water jet (helispheric current sheet –heliosheet ), they disperse around 360 degrees.
Now position an industrial air extractor next to your hose (to simulate the sun’s gravity pull). Outgoing jet of water is hardly affected, but what about water droplets bouncing of the wall? I suggest if any caught by the jet will be swept back (and hit the wall again), those outside the jet (heliosheet) will get pulled in by the extractor (sun’s gravity).
As simple as that.
Some time soon we may have a compression problem similar to the sound barrier for aircraft. The solar wind banking up against the cosmic particles could produce a severe boundary layer that is not conducive to electronics the sparks may fly. I am hoping it has no trouble and gives us a small insight into free space devoid of the suns influence..
What we learn maybe profound in its message to science.
vukcevic says:
December 15, 2010 at 1:48 am
Re: Escape velocity from the sun (a year earlier) is nothing to do with it if protons eventually slow down.
Should not be in italics; my comment and not Dr.S’s quote.
[Easy fix employed ….. bl57~mod]
Re Anything is possible says:
Depressing thoughts for an SF fan. Impressive performance from Voyager though and an inspirational achievement. Latest data also makes musing about solar sail performance more interesting. Aint science great?
As for popping over to Alpha Centauri, we need more power! Which also opens up fun what if scenarios. Gen 1 colony ship leaves to build new home in Alpha Centauri, arrives and finds Gen 5 colony ship got their first. Assuming there’s something there to colonise, and assuming it could be habitable or made habitable. And assuming we could model it’s climate. We struggle with our ‘simple’ solar system, that one has 2 or possibly 3 suns to factor into climate models :p
vukcevic says:
December 15, 2010 at 1:48 am
Dr. L.S
what makes them go up there?.
Simple physics. On many occasions you quoted garden sprinkler as an analogy of solar wind.
It ain’t bad in the day
If they squirt it your way
‘Cept in the winter when it’s froze
An’ it’s hard when it hits on your nose
-Frank Zappa: Uncle Remus-
tallbloke says:
December 15, 2010 at 12:52 am
then they must surely accumulate at the boundary with the heliosheath.
And they do [in a fashion]. The result is called the ‘Hydrogen Wall’ which also contain interstellar ions. The whole shebang eventually slides off to the side and merges with the galactic medium.
vukcevic says:
December 15, 2010 at 1:11 am
Electrons combine with the incoming galactic ions, creating ENAs
The ENAs move so fast that gravity is negligible.
pulled back by the sun’s gravitation, eventually spiralling into the sun’s at the high latitudes.
Why at high latitudes? There is also a solar wind at high latitudes. Those particles should then go sideways and spiral in at low latitudes.
Anyway, the solar wind does not come back but goes sideways [the sideway speed is large enough to keep the particles from falling in, just like the sideways speed of the Earth prevents it from falling]. The solar wind plasma eventually mixes with the interstellar galactic plasma at distances of 1000 AU.
simple physics
Einstein: “make it as simple as possible, but no simpler”.
There is still some very cool science out there in space, everything from Hubble to Swift digging deep into the past and giving us images and data of our universe no one could have imagined in 1977. Unfortunately space travel beyond Mars, for humans, is running into very serious roadblocks, not the last of which is our own short time in this universe and our inablilty to rapidly aclimate ourselves to weightlessness over extended periods. However, getting something like Voyager, only much smaller, packed with the latest technology, close to the speed of light should be a top research priority. Think about how much space you would need for somthing with the computing power of a smart phone in 1977. We should beable to scale down for sattelites as well and set up launch sites outside of earth’s gravity.
vukcevic says:
December 14, 2010 at 2:03 pm
Funny what you say…..they will be “surprised” by the outcome..
What goes up must come down
spinning wheel got to go round
Talking about your troubles it’s a crying sin
Ride a painted pony
Let the spinning wheel spin (Blood, Sweat & Tears lyrics).
I understand that the EPA has determined that V’ger 1 and 2 are contaminating the Universe and that they must both be retrieved and dismantled by 31 Dec 2012. The cost will be absolutely mindblowing and the United States will cease to exist, but the environment is the environment and, regardless, the regulations that the law authorizes the current EPA Administrator to dream up must be obeyed. (Oh yes! Sarc Half Off. There’s always a grain of truth in every ‘joke’.)
Robert of Ottawa says:
December 14, 2010 at 5:07 pm
vukcevic,
generally, space plasmas are neutral in charge, so there is no electrical current.
THERE IS NOTHING NEUTRAL IN THE UNIVERSE. Entiende?. We’ll be neutral….the moment we die. We have been wrongly taught , for example, that a glass ash tray (to put the ashes of cigarettes -another forbidden issue-)it is a dielectric and so we “believe” it is neutral and, worse!, “solid”…however when making glass vials for injections these must be “neutral”(i.e. having a very low reactivity with the liquid which will be contained in it).
Πάντα ῥεῖ καὶ οὐδὲν μένει
Everything flows, nothing stands still
Heraclitus of Ephesus (c.535 BC – 475 BC)
And in order to move ahead, you gotto have one foot ahead of your other foot, and the angle between your legs (or between the “legs” of a triangle) it is called, by electrical engineers, the “phase angle”, which, in the case of alternate current it is 90 degrees. But this angle can vary, as it is the sum of sin y+cos y.
Everything in the universe “walks” or “flows” and this is done by vectors moving their legs as we do.
This is why, also, women walk behind men, in the Japanese culture 🙂
This is real science – unlike CAGW. The wheels have come off that bandwagon, and it’s no fun bashing it any more, everybody is a denier. It’s the weather wot dunnit, innit?
How about this – why has Voyager 1 not experienced the anomalous decceleration experienced by Pioneer 10, apparently defying our understanding of gravity? Completely O/T here, but anyone know of an appropriate blog?
You’re not alone there. However, we are part of a dying breed. NASA stopped inspiring, so there are fewer young people who even believe it’s possible to push into the final frontier in an meaningful way. I imagine I am one of the last who was so inspired, though it wasn’t so much by NASA as by a NASA rebel who wrote a very good book on becoming a space-faring society and why we should be doing it.
I disagree with this. I would say that humanity is against the same wall that the developed world in Europe was against when it looked at the Atlantic Ocean 500 years ago. There’s nothing in space that can’t be overcome. We may not ever achieve faster-than-light travel, but that’s no reason why humanity can’t move beyond this star. Even if it takes multi-generational spacecraft of asteroid-sized mass travelling at tiny fractions of c, it can be done, and if humanity can survive long enough without killing each other or falling victim to a solar-system disaster, it will be done. In fact, it’s likely we’re in better shape than the explorers in Spain were up against, at least we can see what’s out there before we get there. Those men on those wooden ships had no such comfort and some likely believed they were on a suicide mission.