Has Voyager 1 exited the solar system? According to NASA, and as reported in the New York Times and dozens of other media outlets, the answer is “yes”, because Voyager 1 is now surrounded by plasma from interstellar space, not plasma from the Sun. (In other words, Voyager 1 has left the heliosphere.) According to Astrophysicist Summer Ash, in the video above, it’s not even close. The farthest known set of objects subject to the Sun’s gravitational force is the Oort cloud, which hangs out at about 100K Astronomical Units (AU). Voyager 1 is at 125 AU. It will reach the Oort Cloud in roughly 30,000 years. I report, you decide. Open thread.
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ericblair
Something scientifically interesting happened, which is the important part. Unless the probe leaving the Solar System means we have to start paying taxes to the Alpha Centaurans, this just sounds like another smartass nontroversy. It does help to give people the idea about how brainbogglingly humungous the distances involved are.
burnspbesq
A brand-new blog focusing on national-security-law issues hits a home run in its first at-bat.
http://justsecurity.org/2013/09/23/time-retire-military-commissions/
I’m bookmarking this blog, and I recommend that you do so as well.
MattF
This is actually a little tricky because gravity is a ‘unshielded long-range’ force– one can make an argument that you will never really escape the influence of a gravitational well, no matter how far out you go.
The ‘unshielded’ part of the description contrasts gravity with the electromagnetic Coulomb force– the Coulomb force is long-range, but because, in the real world, there are generally both positive and negative charges lying around, if you get far enough away from an electromagnetic charge, its effect really does, eventually, go to zero. Which is not the case for gravitation, since mass is always attractive.
SP
Isn’t everything in the universe in the gravitational field of everything else? Sure, it diminishes as the square of the distance but how can they say “farthest known set of objects subject to the Sun’s gravitational force is the Oort cloud” when I could sit down with high school physics and, knowing the mass and distance apart of the sun and Alpha Centauri, figure out the gravitational pull between them?
drew42
Doing the math: 93 million * 100,000 = 9.3 trillion miles, or just under 2 light years. Is that correct?
If so, and considering that the nearest star is just over 4 light years away, does that mean the end of our system (if defined by the outer edge of the Oort cloud / gravitational pull) essentially ends where the nearest stars’ systems begin?
RP
Eh, close enough.
Keith P.
AFAIK NASA has not said Voyager has left the solar system, as the solar system includes the Oort Cloud. It’s left the heliosphere.
Redshirt
Scientific semantics. The Oort Cloud is definitely part of our solar system, as it is a sphere of ice particles that orbit the sun, way, way, way out. But it’s probably past the heliosphere.
That said, I love the idea of picturing every solar system as a puffy white ball like a flowering dandelion, a core of a star surrounded by a shell of ice. It’s beautiful.
Poopyman
Yeah well, as with most things it depends on what your definition of “solar system” is. Some Say ™ that it’s where the sun’s plasma field is matched by other stars – the heliopause. Others say (per Dr. Ash) it’s where the gravity field of the sun is balanced by other stars. The difference is between ~100 AU and 100,000 AU.
We report, you decide. Hey! Maybe Newsmax can let its readers vote!
mistermix
@Keith P.: The headline of the Times story is “In a Breathtaking First, NASA’s Voyager 1 Exits the Solar System”
J
Call me old fashioned, but if it’s beyond the orbit of Pluto, it’s left the solar system in my book.
jeffreyw
Peak Voyager is just a theory.
ruemara
@mistermix: A dumb reporter/editor can ruin the facts of a story. I should know, I’ve been/suffered through one.
I spent Sunday posting bible verses conservatives don’t read. It was interesting how many godbothering, prosperity gospel types who are nominally Democratic (because we’re black) were just as silent as the conservatives I know. The atheists loved it and had ball in the discussion. It was interesting.
Punchy
At least in theory, does the force of gravity ever actually go to to zero? Aren’t all things everywhere in the universe subjected to each other’s gravity, albeit in infintesimal amounts in many cases? If “influence of sun’s gravity” is the maykerbrake for innie/outtie of the Solar System, can I posit that it will never happen?
Edit: looks like several already beat me to this…
Redshirt
@J: There’s larger “planets” past Pluto. Say hi to Eris.
Redshirt
@Punchy: Within a galaxy, gravity reigns supreme. Even in collections of galaxies, gravity rules. But once you go beyond groups of galaxies, Dark Energy is the supreme force and it functions like anti-gravity, pushing everything apart.
The Moar You Know
@J: I would have to call you old-fashioned. There are four minor planets beyond the orbit of Pluto, at least two of them larger than Pluto.
max
I’m with Keith P. Voyager passing through the heliopause isn’t necessarily exiting the solar system, depending on how you define ‘solar system’. That said, the place where you break contact with the solar wind is as good as place as any to mark the edge of town. However, putting the Oort cloud aside (besides everyone believes it exists, but nobody knows exactly where the hell it is, or how many objects are part of it), Voyager still hasn’t broken contact with the solar magnetic field, which is puzzling everyone.
max
[‘Needs moar probes.’]
LittlePig
Voyajur, Voyajah.
Punchy
@Redshirt: “Dark Energy” is a great nick de nom for Obama. Let’s push this.
Mnemosyne (iPhone)
OT for old movie fans: my next essay will be on “Love Me Tonight,” which is airing TONIGHT at 8 pm ET/5 pm PT on TCM. It stars Maurice Chevalier, Jeanette MacDonald and scene-stealer Myrna Loy.
Redshirt
Anyone ever hear the stirring tale of Spacebat?
shortstop
@jeffreyw: Awesome.
handsmile
@burnspbesq:
Many thanks for that alert/recommendation of the “Just Security” blog. Most promising.
Just among the executive and founding editors whose work I have some familiarity with (e.g, Ni Aolain, Cole, Koh, Lederman, Waldron), that’s a formidable roster of theorists and practitioners. Sure to be a regular visitor there.
Chris
How long before the wing nuts blame Obama for “Losing the Voyager”.A la losing the Panama Canal… . I been chuckling about that for weeks now…
schrodinger's cat
My tiny blog hits the 100 post mark! Thanks BJers. Hoping that it goes on like Voyager.
schrodinger's cat
@Chris: Did he lose it in the Delta Quadrant? He is the Caretaker! it makes complete sense.
Botsplainer
My theory is that Terran biology is largely confined to Sol’s gravity well until the end point of its existence. Escape will be limited to nonbiological intelligence, as even high subliminal speeds wreck biology over any length of time due to the effect of particle impacts.
Travel even locally will be slow – even Mars presents a huge challenge in terms of throw weight, health and food/water/O2, not to mention radiation shielding.
Sister Rail Gun of Warm Humanitarianism
@Redshirt: Crystal spheres.
Snarki, child of Loki
Voyager 1 hasn’t left the solar system YET.
Because it hasn’t passed the sign that says “Did you bring your towel?” on OUR side, and “Mostly Harmless” on the other side.
Belafon
@Botsplainer: Kind of like we’ll never fly? I do understand what you are saying: It would probably take a forest in a ship with existing technology, or a star in a ship with what we can think of right now. But, you never know.
schrodinger's cat
@Belafon: There is so much we don’t know, dark matter and dark energy, we are really out in the dark about most of the stuff in the universe.
Villago Delenda Est
@Botsplainer:
Scotty will come up with something to make all that bad stuff go away.
sparrow
@Punchy: Mathematically, no. Effectively, yes. But as an astrophysicist I’m happy to see lay people discussing the awesome success that Voyager represents. I mean it has a recording from Jimmy Carter on it, because that’s who was president when it was launched! And it still sends back signals! Holy crap.
Roger Moore
@SP:
Every object in the universe may experience the sun’s gravity, but for most of them it’s a minor influence. Things that are as close as the Oort Cloud have a stronger influence from the sun’s gravity than anything else (unless they’re in orbit around another Oort Cloud object, of course), which is what they mean by “subject to the sun’s gravitational influence”.
Villago Delenda Est
@Snarki, child of Loki:
THIS
Anne
Ash is (and commenters are) correct that it really depends on how you define “solar system.” I figure that the science we’re hoping Voyager helps us do is more along then lines of “how about this interstellar plasma?” than “what happens when there’s nothing else around us bound by solar gravity?”
With that in mind, once it crosses (crossed) the heliopause, it’s out of the solar system.
Jeffro
I say it has left because…just once I want to ‘do’ science like a Republican, and have my belief make it so.
Bye Voyager!!
Villago Delenda Est
@sparrow:
Thank goodness it doesn’t have a recording from Ronald Reagan on it, because then the Klingons would move in and annihilate us for sure.
Redshirt
@schrodinger’s cat: Neelix and his cooking awaits us, in the stars!
schrodinger's cat
@Redshirt: The most annoying Star Trek character ever!
? Martin
@MattF:
Though true, there is also the concept of a gravitational sphere of influence, which is the region in which a given body has the primary influence. This is a (generally) hierarchical arrangement, so you could be in the Moon’s SOI, while also being in the Earth’s and the Sun’s. These probes will be in the Sun’s SOI for quite some time, but they’ve also been on escape trajectories, so while they’re influenced by the Sun’s SOI, they aren’t captive to it.
But that’s not the measure here. The measure is the solar pressure. And I would argue that does qualify as leaving the solar system, because it’s the first place where the sensors surrounding the craft are able to measure things that do not originate from our solar system. Sure there are things in the system that do not originate here like comets and such, but they’ve all been subject to solar radiation before you can observe them and that solar radiation has a lasting physical impact. Voyager is now making direct observations of stuff that has never been ‘polluted’ by the Sun, other than its gravitational influence which as noted above has no limit and technically influences everything in the universe.
Matt McIrvin
“In interstellar space” and “outside the solar system” are not the same thing. By JPL’s definition, interstellar space extends way inside the solar system.
Redshirt
@schrodinger’s cat: Probably. Tom Paris is up there. And Chakotay. And 7 of 9. And Cap’n Quantum Leap… oh Star Trek, how you’ve failed me.
Villago Delenda Est
@schrodinger’s cat:
I don’t know. Harry Kim was pretty annoying, too. But he and Neelix are definitely the two most annoying Trek characters, ever.
Face
Would be pretty cool if they could find a way to turn it around and have it come back to Earth….
Redshirt
@Face: Google “ST:TMP”
Villago Delenda Est
@Redshirt:
OK, I grant you Capn’ Quantum Leap, but that entire iteration (with a few exceptions) blew fantastic chunks of protomatter all over the Alpha Quadrant.
schrodinger's cat
@Redshirt: Still better than Captain Archer and his crew. I stopped watching after the first couple of episodes.
ETA: 7 of 9 grew on me. The Doctor and 7 of 9 were the best characters on the later seasons of Voyager.
piratedan
ty for the Telefon reference in da title
Redshirt
@Villago Delenda Est: I think you mistake me. “Enterprise” was an abomination. I – a life long Trekkie – gave up on that show after suffering through 3 years of it. Painful!
The real villains are Berman and Braga, of course.
schrodinger's cat
@Villago Delenda Est: Harry Kim was bad, they should have killed him off at the end of Scorpion.
Redshirt
@schrodinger’s cat: Lots of people should have died on Voyager. It should have been a much “grittier” series. So much wasted opportunity. Doubly so for “Enterprise”, which could have been fantastic.
Villago Delenda Est
@Redshirt:
To Grethor with both of them. Ptuii!
Villago Delenda Est
@schrodinger’s cat:
Oh, absolutely. It helped that the actors portraying them are very talented. The episode where the Doctor “takes over” 7 of 9 demonstrated just how good an actor Jeri Ryan is.
LanceThruster
I will be glad when all you God-deniers are eating crow when Voyager falls off the edge of the ecliptic plane.
That’ll show you.
Jewish Steel
@burnspbesq:
That was a good article.
Bit of an understatement there.
scav
@LanceThruster: Voyager will no doubt be sending back more reliable, consistent and useful communications as it tips over the edge than god ever did. Even with Neelix baking the wafers.
chopper
@mistermix:
and the times’ headline proves what, exactly, with regards to what NASA actually said?
Villago Delenda Est
@LanceThruster:
Not to worry. One of the turtles will catch it.
There are so many of them…
burnspbesq
@Jewish Steel:
Every time someone writes something about how hard it is to get anything done in Congress in the current environment, we should all treat that as a message about the importance of getting heavily involved in the 2014 elections.
Redshirt
Voyager will still be sending data back long after America has collapsed and reverted to a savage, technophobic theocracy. If all the receiving equipment has not already been smashed, then maybe in a couple hundred years some red neck Priest/Warlord can use the BEEP-BEEP-BOOP signals from Voyager as a sign from GOD.
Just Some Fuckhead, Thought Leader
Let’s say as a matter of reference that “He’s got the whole world in His hands”. Where would this put the Voyager? Somewhere along His forearm, maybe as far as His elbow?
Yatsuno
@Redshirt:
We’ll always have the dishes in Australia. They could revert to a savage theocracy as well, but I doubt it, as that will involve less beer.
@Just Some Fuckhead, Thought Leader:
Top of the wrist, maybe. It’s a big universe.
LanceThruster
@Yatsuno:
What if His arm was pinned by a rock so big He Himself could not lift it, eh?
Redshirt
@Yatsuno: A hopeful thought, but, as everyone knows, in the future Australia will be a land of punk warlords and feral, wolf children. Also, razor boomerangs.
Villago Delenda Est
@Yatsuno:
When I was visiting Australia, in 1988, they were celebrating their 200th birthday. I pointed out that we (the US) got the religious nuts, and they (Australia) got the thieves, murderers, and prostitutes, which means they won.
Bill E Pilgrim
Wait until it reaches the Ork cloud. After the first 37 “Nanu nanu”s in a row it will make a u turn and head home.
Penon
I’d just like to say: Summer Ash is a fabulous name for an astrophysicist.
AxelFoley
@LittlePig:
V’Ger!
Yatsuno
@Bill E Pilgrim: Okay I chortled. France is awful damn lucky to have you you know.
AxelFoley
@Villago Delenda Est:
Sto-vo-kor!
LanceThruster
We’ll know it’s there when it reaches what Alan Arkin’s “Simon” called “out of space.”
tybee
@AxelFoley:
i was wondering why that low hanging fruit had been ignored
Redshirt
@Sister Rail Gun of Warm Humanitarianism: Cool reference. Thanks! Makes me wonder how difficult it will be for a space craft to cross through the Oort cloud. All it would take is a small bit of ice to smash it, and there’s plenty of ice out there, in all directions.
Cool and true fact: The gold records on the Voyagers will most likely be the last bits of humanity that remain. They might last for billions of years. It would be cool to see the aliens of the future pick up a record and go, “huh?”.
The Moar You Know
@Redshirt: Depends on when you think that reversion will happen. Voyager will start a controlled shutdown of its remaining systems about 10 years from now IIRC. Will not have enough power to turn anything on within thirty years at the outside, and I think NASA has it scheduled to shutdown entirely in 20.
RTG’s are great – best form of long-term no-maintenance power humanity has ever come up with – but people overestimate how long they last. Yeah, it’s true that plutonium has a half-life of 80 million years, but it only takes a few centuries before it’s no more radioactive than the ores it is made from in the first place.
Redshirt
@The Moar You Know: Yeah, I was being hyperbolic. I heard 20 years too. The Pioneer probes (the other probes which will leave the solar system) were shut down a while ago.
Does anyone know if New Horizons is on an escape vector after it fulfills its mission at Pluto?
Villago Delenda Est
@AxelFoley:
Those two don’t rate Stovokor. They’re on the barge of the damned.
chopper
the oort cloud is thought to exist. it makes sense given the periods of the comets we have observed, but there are no actual observations of a massive cloud of trillions of objects existing there.
saying voyager hasn’t left the solar system because it hasn’t yet gone through a barrier we think exists but can’t actually show is there is a bit funny if you ask me.
chopper
@Redshirt:
it aims to check out a few objects in the kuiper belt and scattered disk if possible, so yeah it’ll head out. voyager has a hell of a lead tho.
Cermet
@Redshirt: Yes – New Horizons has far more than enough velocity to escape our solar system but it will never match, must less exceed, Voyager’s velocity; that craft got a huge gravity throw/push by Jupiter and that has made Voyager the fastest human made object to date.
AS for whether we can ever leave this system, this might be possible for people in the future (well after we have fusion power at the very least.) Faster than light travel is now known to be within the laws of current physics (would require negative energy to enable stretching/compressing of space around the craft) – doing it, however, is still far, far beyond our technology.
Redshirt
I ask about New Horizons only because I assume the tech on it is far, far superior to that on the Voyagers, and thus we might get a lot more data out of it as it leaves, for a longer period.
That might be the last craft we shoot out of the solar system for a while, as we regress back to your traditional savage theocratic foundation.
Jebediah
@MattF:
Hence chubby chasers.
Heliopause
Ahem.
Redshirt
@Heliopause: So, the question is: Are you THE solar system, or just a part of the solar system?
Long Tooth
Mistermix: You’re the guy at the table who deflates a good vibe, wonder in awe moment.
Not that I’ve personally been involved in many of those moments. If any at all.
MM: “Actually, no. It’ll be 30,000 years from now, in fact”…. [long pause] “Do you dig Battle Star Galactica”?
Bill D.
@The Moar You Know:
That statement has problems.
1. “Plutonium” is not one single substance and it does not have one single half-life. Like all elements, each isotope of Pu that’s not stable has a different half-life. Pu-238, used to power some spacecraft, has a half-life of 87.7 years because it’s really radioactive. Pu-239, used in some nuclear reactors and nuclear weapons and the usual isotope people worry about, has a half-life of 24,000 years. Pu-244 has a half-life of 80 million years. You can’t lump these isotopes together as if they behave the same way.
2. The rate at which a reasonably pure lump of a given isotope becomes “no more radioactive than the ores it is made from in the first place” will vary depending on the half-life. If the isotope is much more radioactive than the ore (due to concentration), that period must be *much* longer than one half-life. After one half-life, half will be gone (actually, converted to other isotopes of the same or different elements which may or may not be radioactive). After a second half-life, half of the rest (or three quarters cumulatively) will have been converted, and so on. The usual rule of thumb is that it takes around 20 half-lives to get back to the degree of radioactivity of the original ore, but that’s only an approximation.
3. However, due to its short half-life Pu-238 doesn’t come from ore. Any that’s produced in nature in tiny amounts doesn’t stick around long enough to be concentrated by geologic processes into useful ore. Instead, this isotope is produced by deliberate irradiation of other isotopes.
Redshirt
Uranium is heavy. Likely much of it sits at the center of the Earth, glowing. Like all the heavy metals, in spheres around a central ball of denseness.
Jockey Full of Malbec
@Botsplainer:
It’d be nice to, you know, actually test this theory. Before we collectively decide “meh, nuh worthit” and go back to Facebooking until the sun turns red and boils off the oceans. Thrilling future, that.
I have zero doubt that the human race (or, perhaps, something that springs from humans) will litter itself all over the solar system at some point. There are resources out there. And we are the most ruthless resource-hunters that have ever existed (at least in this neck of the woods).
I’ve come to realize, however, it will not be this particular culture that makes this happen. The Anglo-American model relies too much on ultra-cheap resource extraction costs, and a convenient local population to exploit– neither of which holds true off-planet.