Voyager 2 Shows Solar System Is "Dented"

Selikoff writes "NASA's Voyager 2 spacecraft has found that our solar system is not round but is 'dented' by the local interstellar magnetic field, space experts said on Monday. The data were gathered by the craft on its 30-year journey when it crossed into a region called the 'termination shock.' The data showed that the southern hemisphere of the solar system's heliosphere is being pushed in. Voyager 2 is the second spacecraft to enter this region of the solar system, behind Voyager 1, which reached the northern region of the heliosheath in December 2004."

Shape?

[TitusC3v5 (608284)]

Could somebody explain how exactly the solar system has an innate 'shape'? I would think that that would be human-defined, not an actual, measureable feature.

Re:Shape?

[Kranfer (620510)]

Its not the solar system that is dented but its far reaches where the solar wind suddenly slows down that is 'dented'. Figure a magnetic field or a sphere that is effected by its environment and causes it to lose its shape... The area where the solar wind slows down changes in shape due to interstellar influences... gasses, magnetic fields, etc... From a few articles I read on this the other day Voyager 2 passed through the terminal shock numerous times so far and will again in 2008 because it is constantly changing shape. Although I may be wrong, and I have been up all night sick and decided to go into work at 4 am... I dunno what the hell is wrong with me lol.

Re:

[Gabrill (556503)]

Ok how long apart are these 2 (count them 2) points of reference? V2 also crossed the boundary what, 5 times? It seams to me that this could be stronger evidence that the whole thing fluctuates in size, rather than having a hard, irregular boundary.

Re:Shape?

[by Anonymous Coward]

This is the common method of viewing what termination shock is on earth: go to a sink and turn it on, as you will see in the basin, when the water hits, its ejected out on all sides. On the outskirts of the basin, where the water is forced by gravity back down, the water will become regular, non-moving, etc. This is the interstellar medium, the ambient pressure from outside our solar system is pushing against the solar wind (the water thats rushing away from its impact location) creating a location thats called termination shock. This location, as you can clearly see, is moving, always fluctuating. It changes its shape in response to the outside pressure (which here on earth, is caused by gravity wanting to pull the water down in the basin). You can probably easily see how a object could pass this boundary several times, especially when you realize that our solar system is much, much bigger then this example. A dented shock boundary could occur when, for whatever reason, the rushing water is being pushed back sooner. Perhaps there is more pressure on that side, or, in the case of space, you have some magnetic influences acting against the solar wind. Granted there could be other reasons, but the smart minds of today say its probably magnetic influences.

Re:Shape?

[MichaelSmith (789609)]

Could somebody explain how exactly the solar system has an innate 'shape'? I would think that that would be human-defined, not an actual, measureable feature.

Well the Sun has an innate shape. It is mostly a sphere, flattened a little bit by rotation. Other factors such as magnetic fields will play a part.

The solar wind is really the outer part of the sun, so in one sense we are embedded in the sun, and it flows around our planet. It has long been expected that the solar wind would meet the interstellar medium at some sort of bow shock on the upstream side with a tail of sorts on the downstream side.

This article suggests that magnetic fields which exist between stars also affect the shape of the boundary between the solar wind and whatever is outside it. Instruments on the Voyager spacecraft tell us which medium it is in at any point in time.

Re:Shape?

[Chuck Chunder (21021)]

It is human defined in a sense, however the humans in question aren't arbitrarily picking a point, they are basing the definition on a measurable physical property, ie the area where the Sun's magnetic field has a (dominating) effect.

Re:Shape?

[entrigant (233266)]

See: http://en.wikipedia.org/wiki/Heliosphere [wikipedia.org]

Basically the suns solar winds push back interstellar matter. This can have a shape.

Re:

[rucs_hack (784150)]

Basically the suns solar winds push back interstellar matter. This can have a shape.

So what your saying is, out there in interstellar space is a giant space kitteh saying 'I has a shape, let me apply it to you'.

If it drops some giant space kitteh kibble while doing this, we are so screwed..

human defined?

[someone1234 (830754)]

Hmm? Is there anything known to us humans, that isn't human-defined?

Re:human defined?

[somersault (912633)]

McDonalds?

Re:

[orclevegam (940336)]

Pi? I've certainly never seen a complete definition of it, only approximations.

Re:

[AeroIllini (726211)]

Except those approximations of pi are expressed in (usually) base-10 notation, which is a human-created construction.

Asking if there is something that exists that is not defined by humans is a tricky question. All of these things "exist", but all the tools we have for sensing them and measuring them are largely based on human-defined systems of measurements. We can't talk about these things without resorting to standards of measurement, which are wholly arbitrary and based on human experience.

So, yes, there

I, for one...

[sammydee (930754)]

Actually think it's awesome that even twenty YEARS after it's launch, voyager 2 [wikipedia.org] is STILL doing useful science. Another thing that astounds me is how the engineers managed to ensure that even after all these years in the hostile environment of space, this machine is still perfectly functional.

Re:

[Kranfer (620510)]

I find it amazing as well. However, I know that someday Voyager will stop functioning and will shut down from lack of nuclear fuel... or be destroyed by Klingons... or even return to Earth is a horrible epic adventure involving the Enterprise....

Its not really hostile

[MichaelSmith (789609)]

• Temperatures are extremely stable, so there is no expansion or contraction
• Your electronics can't get rained on or filled with dust
• There are no rats to eat your wires (yet)
• There are no engineers around to fiddle with it and improve it (yes I know this does happen to software)
• Cold is generally good for equipment, but not too much of course.
• Your chance of being hit by a meteor is probably less than on Earth
• etc

If I ever do the transhuman thing and get turned into software, The Oort cloud is where I would want to be for serious durability.

Re:

[cheater512 (783349)]

Although its only a matter of time before Mynocks get to it. :)

Re:Its not really hostile

[coinreturn (617535)]

Cold is generally good for equipment, but not too much of course.

Actually, the "cold" of space doesn't help at all. Because the density of particles is so low, spacecraft can't cool down by convection. Cooling spacecraft (eg shedding internally generated heat) is a big problem. Also, the main "harsh" ingredient of space is radiation. The technology used in spacecraft is usually way behind commercial technology because it also has to be "rad-hardened."

Re:I, for one...

[Eternauta3k (680157)]

Actually, voyager 1 and 2 stopped working after a few months, current "findings" are just invented by NASA.

The Truth

[ScotlynHatt (764928)]

Okay folks, I have some bad news for you. Human space exploration is deforming the universe and stuff. You heard it here first. I declare this anomaly "Universal Warming." What's higher than the Nobel prize?

Obviously

[by Anonymous Coward]

Obviously, the reason the solar system is dented is because God dropped it.

Dented?

[Centurix (249778)]

Good job we have third party insurance on this sucker, I'd hate to see what we hit...

It seems logical

[laejoh (648921)]

that the birthplace of Arthur, Sector ZZ9 Plural Z Alpha, contains something that appears Dent(ed).

Re:

[Mikachu (972457)]

What does the Z mean?

Which Z?

All of them.

Is this any better than conjecture?

[by Anonymous Coward]

AFAICT, they have one data point on the surface of the 'sphere'. Using that one data point they decide that the sphere isn't spherical. If they had a hundred Voyagers all leaving the solar system in different directions at the same time, I would be more convinced.

Re:Is this any better than conjecture?

[andphi (899406)]

Actually, they seem to base their conclusion on the fact that Voyager 1 and Voyager 2 don't seem to have entered the termination shock at the same distance from the earth.

FTA:

"Voyager 2 entered the termination shock almost 1 billion miles closer within the southern hemisphere of the heliosphere of the solar system than Voyager 1 previously had," said Voyager Project scientist Edward Stone of the California Institute of Technology.

Re:Is this any better than conjecture?

[MikeyVB (787338)]

Actually, they seem to base their conclusion on the fact that Voyager 1 and Voyager 2 don't seem to have entered the termination shock at the same distance from the earth.

Actually, they seem to base their conclusion not only on that fact, but also because they had theorized that it might be that way from computer models that predicted when Voyager 1 and Voyager 2 reached the termination. So far Voyager 1 (actually, not sure on V1) and Voyager 2 reached the termination shock around where they thought they would according to the model that the Solar System is asymmetrical as described in TFA. (This [www.cbc.ca]arcicle briefly mentions the computer model)

Re:

[prefect42 (141309)]

Two data points, surely? And if they're right, they expect more in the future...

My bad

[commodoresloat (172735)]

Sorry folks, this was my fault. The folks were out of town and I figured I'd take the solar system out for a spin. I took a hard right to dodge a black hole and one thing led to another... Anyway, sorry about the dent; I'll pay for the damage.

Halp!

[Fizzl (209397)]

southern hemisphere of the solar system's heliosphere

Could someone remind me how to orientate myself in the universe?

Re:Halp!

[JustOK (667959)]

Up is the shortest distance out of your head. In most cases, its best if "up" is not in the same direction as the dominant gravity source.

Re:

[fbjon (692006)]

It's even simpler: Google is always up, TFA is always down.

Re:Halp!

[andphi (899406)]

The Enemy's Gate is Down.

Re:Halp!

[Gabrill (556503)]

Right hand rule. Fist your right hand, and the fingers indicate direction of spin. The thumb indicates North. Most of the Milky Way galaxy follows this rule, in conjunction with Earth (excepting Uranus, not a team player).

Re:

[rb4havoc (822483)]

So basically, Uranus is the Dennis Rodman of Planets?

Re:

[TimeTraveler1884 (832874)]

Most of the Milky Way galaxy follows this rule, in conjunction with Earth (excepting Uranus, not a team player).

No kidding, that guy is a real ass.

Re:

[Bacon Bits (926911)]

Perhaps towards Polaris. Or you could use the celestial pole.

Or you could use the plane of the solar system which contains planetary orbits as the "equator" and then decide to orient one as "north" to either the celestial pole or the pole star.

Really, it's not that hard.

Still a very good Solar System.

[Thanshin (1188877)]

"Very Good - Looks fine at arm's length, but looking closer reveals soft corners and other imperfections."

There goes our hopes for a near mint Solar System.

Someday we'll finally end destroying the Earth and start with the rest. This gives us a head start.

another ding in the solar system

[yagu (721525)]

Should have parked farther out, not close to any other solar systems. Probably won't even meet the deductible.

That's a relief

[Steeltalon (734391)]

It's good to know that the grocery store won't charge full price for our solar system.

I have updated Wikipedia to reflect this

[thomasdz (178114)]

RE: "Voyager 2 Shows Solar System Is "Dented", and "our solar system is not round"
The Wikipedia entry for "Solar System" has a bunch of silly stuff about planets and moons and asteroids and other useless stuff, so I've deleted it all and replaced it with the much more informative: "not round, but Round-ish" ...update: Grrr... some wiki-fanboi perfectionist editor has corrected it to read "sphere-ish" ... oh well, at least my edit has a reference source so I guess I'll just take it up with Jimmy Wales

King of All Cosmos went on a bender again...

[Genom (3868)]

Looks like the Prince has some rolling to do.

Re:I don't get it

[MichaelSmith (789609)]

how does the spacecraft survive in those temperatures?

The density is very low. The body of the spacecraft might get hit by individual molecules which have that temperature, but what are a few thousand molecules going to do to it?

Re:I don't get it

[sqldr (838964)]

As an analogy, it's like smoking. You're breathing particles at up to 6000 degrees C, but it doesn't do (much) damage.

Re:I don't get it

[hey! (33014)]

My hat is off to you. You, sir, are a master of irony.

Re:I don't get it

[by Anonymous Coward]

Probably simple physics ... remember, the density of the gas in space is very low (almost non existant); this implies that there are very few particles hitting the craft at that temperature. Meaning that the craft only needs to have roughly 10000 times the density of space to operate at a "normal" temperature. Given the craft is made out of solid things like metal, that shouldn't be too hard...

Re:

[smitty_one_each (243267)]

I'll venture, given the fractal nature of reality, that this is just the http://en.wikipedia.org/wiki/South_Atlantic_Anomaly [wikipedia.org] writ large.

Re:

[Technopaladin (858154)]

I ANAAP but Earth is 8 Light minutes from the sun...so I would suspect we are talking an hour or so.

Almost 12 light-hours, actually

[yeremein (678037)]

This article [newscientist.com] says it's 84 AU out, which is a little more than 11.6 light-hours [google.com].

Re:

[fbjon (692006)]

How dense is the matter and how do you measure this kind of energy?

Very sparse. With a thermometer.

isn't much

[Quadraginta (902985)]

Matter is unbelievably thin out there. Roughly 1 atom every 10 cubic centimeters. By contrast the best vacuums we can produce on Earth (around a trillionth of an atmosphere) contain 250 million atoms in every 10 cubic centimeters.

It doesn't damage the spacecraft because, as anyone who has put out a candle flame with his fingers can tell you, it's not temperature that is dangerous but heat. Things with very little heat to transfer -- in this case, some unbelievably tiny amount of matter -- but at very hi