Pluto Probe Snaps Jupiter Pictures

sighted writes "The New Horizons probe, on its way to Pluto and beyond, is now speeding toward Jupiter. Today the team released some of the early data and pictures, which are the first close-range shots of the giant planet since the robotic Cassini spacecraft passed that way in 2001."

Comments

This just in...

[muindaur]

Nasa has discovered Jupiters gas was produced by CowboyNeal.

Re:This just in...

[Thuktun]

Like the Planet Express ship, I notice the New Horizons spacecraft has a carbonated logic unit dubbed PEPSSI.

How long does this take?

[XxtraLarGe]

Does anybody know how long does it take for the photo data to be transmitted from that far away (Both Jupiter and Pluto)? Hours or days? I am still pretty amazed that we can send a probe into space and receive pictures from Jupiter.

Re:How long does this take?

[rumith]

10 hours from Pluto in average. 45 minutes from Jupiter in average. Don't know whether they'll in their aphelion or perihelion now, so can't say more precisely.

Re:How long does this take?

[Anonymous Coward]

It doesn't matter how long it takes - I'm curious as to how long it takes for the ever intelligent Richard C Hoagland to report that Nasa is covering up an ancient civilization on Jupiter. The fact that it's now a gas giant is proof that they've left us a message not to eat so many beans. Give that man another Angstrom medal.

Re:How long does this take?

[Bucko]

The New Horizons Site keeps track of the spacecraft position and distance. According to the last mission update, the light travel time is now over 1h 30m.

Re:How long does this take?

[Tom Womack]

http://pluto.jhuapl.edu/science/data_collection.ht ml says that the transmission is at 38kbit/second from Jupiter, and will be at around 450bit/second from Pluto.

Cassini runs at 82kbit/second from Saturn, but it's a probe with a larger power budget.

The imager takes one-megapixel, 16bpp images, and compresses them to 100kbyte files for initial transmission, saving the originals in a few gigabytes of onboard flash; it can be instructed to send back uncompressed images if there's something interesting visible.

So an image takes about 20 seconds to transmit, plus about six minutes if you want the uncompressed version; and it takes 45 minutes to get to Earth from Jupiter. From Pluto, the images will take half an hour for the preview and twelve hours for the uncompressed image.

Re:How long does this take?

[duh P3rf3ss3r]

According to the last mission update, the light travel time is now over 1h 30m.

I have no idea where you got that. From the page you sent us to, the distance to the spacecraft is currently 5.57AU. Dividing that by c gives 2779.46 s or 46.32 minutes. Perhaps it's written somewhere on that site that the round trip light time is just over an hour nd a half. But that's not at all the same thing.

Re:How long does this take?

[gsslay]

Unfortunately it then zips the compressed image into a self-extracting exe, so NASA's anti-virus strips it off at the mail server.

Re:How long does this take?

[Hoi Polloi]

Unfortunately high speed cable internet connections are not available beyond the orbit of Jupiter.

Re:How long does this take?

[Tablizer]

Does anybody know how long does it take for the photo data to be transmitted from that far away (Both Jupiter and Pluto)? Hours or days?

Note that many of the images will be stored onboard and sent after the main encounters are done. This is because it uses up time and fuel to aim the probe back and forth between antenna alignment with earth and science instruments.

To cut costs, New Horizons rotates the whole probe to aim instruments instead of having movable instruments (unlike Voyagers, which had movable platforms). But this means that it cannot do science and broadcast directly to earth at the same time. To get around this, they've loaded up on memory so that images and data can be sent back *after* the main encounter is finished. Some estimates are that it would take 3 months after the Pluto encounter to send back all the data (due to both volume and distance).

The drawback of this is that if the probe has a problem during the encounter, then most info will not get a chance to be sent back. For example, some speculate that Pluto has a faint ring. If the probe smashes into a big ring particle during the encounter, it won't get a chance to send back most of its data.

Because of such risk, they plan to send smaller samples of the data and a few highly-compressed images back just before the primary encounter. That way we at least get some basic info even if there is a dissaster.

Re:How long does this take?

[Anonymous Coward]

it cannot do science and [talk] to earth at the same time.

Sounds like my ex

Re:How long does this take?

[SageMusings]

+10 Damn Funny!

I nearly soiled myself on that one.

Re:How long does this take?

[iamlucky13]

The challenge of getting the data from Pluto, once it's acquired, is definitely non-trivial.

New Horizons has a total of 8 GB of redundant solid state (flash) memory to save data as it's taken. Divide that by the the 450 baud the parent mentioned, and you can see that to broadcast all of that data to earth would take about 7 months, not including overhead related to operating the probe and previewing the most important data.

In fact, New Horizons will perform it's observations of Pluto and Charon nearly continuously for several weeks before and after the closest approach, then spin to point at earth and broadcast nearly continuously for 9 months.

All of this to take what we've been able to discern of Pluto from this to essentially as good as this.

Did anyone remember to tell the probe...

[simm1701]

.. that pluto isn't a planet any more???

I certainly hope so, otherwise it could get really embarrassed when it tries to ask for directions!!

Re:Communication a problem

[$RANDOMLUSER]

Wow, that sure sounds like "spooky action at a distance" to me.

Re:Communication a problem

[AndyST]

> it takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009 Voyager I has a speed of about 17 km/s. At that speed it takes 114440 years to fly the 4,4ly to Alpha Centauri.

All these planets are yours

[$RANDOMLUSER]

Except Europa. Attempt no landings there.

Re:All these planets are yours

[zwarte piet]

That only applies after 2010.

Parent is pure drivel

[Anonymous Coward]

... as you suspected.

well this is where they are

[rucs_hack]

their exact position today can be found in the JPL Horizons database
http://ssd.jpl.nasa.gov/horizons.cgi

so using Sol as Origin [0,0,0], with distance in km and km/s velocity measures:
XYZ position and velocity in Km and Km/sec
V prefix = velocity,

Jupiter
A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-3.523007925524937E+08 Y =-7.203651223053448E+08 Z = 1.087397270750013E+07
  VX= 1.158611696091788E+01 VY=-5.127849980674650E+00 VZ=-2.378734986696975E-01

Earth
  A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-7.005151113800500E+07 Y = 1.294518808525130E+08 Z =-1.647040773451328E+03
  VX=-2.669513206382950E+01 VY=-1.429493892074527E+01 VZ=-5.052885705412180E-04

And the Horizons probe itself is here:
A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-3.141011231236297E+08 Y =-6.673772181265557E+08 Z = 9.200702373118341E+06
  VX= 1.154291925552546E-01 VY=-1.978644188955009E+01 VZ= 1.493924692614632E-01

However it's too early to work out the times taken for signals to travel based on these positions. I need more coffee.

Re:well this is where they are

[KiloByte]

Pythagoras' theorem says the distance in R3 (ie, euclidean space) is sqrt((x1-x2)^2+(y1-y2)^2+(z1-z2)^2).
That is, the distance between Earth and Jupiter right now is: 8.95528824E8 km.

Dividing that by c gives 2987 seconds. So, right now the half-ping is 50 minutes.

By similar calculation, you can get that EarthNew Horizons is 2779.975 s =~ 46 minutes.

Re:well this is where they are

[cyclomedia]

does anyone else here think it seems a bit odd to print a number with 16 decimal places then stick an E+08 at the end, why not just an 8 digit number with 8 decimal places?

i do actually know the TECHNICAL answer: one digit, followed by a bunch of decimal places followed by an exponent is standard scientific notation. Still looks bizzarro to me though

Re:well this is where they are

[rucs_hack]

I frequently include all values after the decimal place up to the first zero. That seems to help precision. If you cut the number down and remove non zero values, it can really hurt accuracy.

It definatelly helps when it comes to Phobos and Deimos, they are a pain to get right.

Re:well this is where they are

[FallOfDay]

The rough & ready, easy-on-the-eye (!), pictorial version is as follows:
http://pluto.jhuapl.edu/mission/whereis_nh.php

Re:well this is where they are

[mdwh2]

does anyone else here think it seems a bit odd to print a number with 16 decimal places then stick an E+08 at the end, why not just an 8 digit number with 8 decimal places?

It means you can see at a glance how big it is, without having to count the digits.

I'm more curious that they think they can measure Jupiter's position to a fraction of a millimetre, or the velocities to a fraction of a nanometre per second...

Re:well this is where they are

[AvyTech]

I just got grrly wood. Yay for me.

Re:well this is where they are

[SavvyPlayer]

I'm more curious that they think they can measure Jupiter's position to a fraction of a millimetre, or the velocities to a fraction of a nanometre per second...

These accuracies result from the mathematics. Why toss out digits simply because we can't be absolutely certain to the fraction of a millimeter/nanosecond of any given celestial object? It costs nothing to keep them and they allow the numbers to be independently verified.

Re:well this is where they are

[pappas.chris]

pics or it didn't happen :D

LOL couldn't resist

(oh and btw the captcha for this post just happens to be "immature"... go figure!!!)

Re:well this is where they are

[SavvyPlayer]

millimeter/nanosecond of any given celestial object

...millimeter/nanosecond of the position of any given celestial object...

Cranky

Re:well this is where they are

[jslater25]

I like to write zero as 0.00E8. How do you write zero?

Re:well this is where they are

[beckerist]

A cool slight diversion: this is exactly the reverse process of how Ole Roemer in the 1670's came up with his estimate of the speed of light.

Re:well this is where they are

[beckerist]

Except, of course, for the fact that it was Io used as a point of reference instead of the probe... But hey, a satellite is a satellite! :-)

Re:well this is where they are

[geobeck]

does anyone else here think it seems a bit odd to print a number with 16 decimal places then stick an E+08 at the end...

I just think the 16 decimal places are kind of overkill because, by the time you write them down, everything after the fifth or sixth one has changed because the objects are moving relative to each other.

Re:well this is where they are

[AvyTech]

And there I thought my maturity level was through the roof with all that tickly action. In all seriousness, though, That calculation just blew up part of my brain. Not that I was using that particular area, but still.

Re:well this is where they are

[theguywhosaid]

depending on who you ask, that could mean anything less than 1e6

Re:well this is where they are

[myowntrueself]

Another cool slight diversion, Rene Descartes said that:

"if the speed of light is ever found to be anything other than infinite then it may be said that I know nothing in matters of philosophy"

So all those who quote his "Cogito ergo sum" should think again!

Re:well this is where they are

[bmo]

"These accuracies result from the mathematics. Why toss out digits simply because we can't be absolutely certain"

Because extra digits do not equal accuracy.

To put it another way, those numbers are nothing more than visual noise. If you can measure something to only four decimal places, it makes absolutely no sense to use any numbers after the fourth decimal place, as they don't represent anything _at all_.

The real world is not like a high-school math class. You don't get any "attaboys" for meaningless extra digits, which is why your science teachers get all excitable about significant digits. Your numbers have to /mean something/.

--
BMO

Re:well this is where they are

[Jugalator]

Celestia fans may find an add-on with improved Pluto orbit accuracy, New Horizons orbital data, and a model for the probe useful for tracking the spacecraft.

Re:well this is where they are

[marsmark]

How do you write zero?

floor(0.49)

Misinformative

[Cheesey]

As I understand it, the speed of light applies not only to physical objects, but also information itself. No-one knows any way to move information faster than light. If you've found a way, that's truly revolutionary, but in the meantime your post sounds a bit like a "free energy" claim. Can you back it up with some citations?

Re:Misinformative

[AndersOSU]

Your right, the speed of information is limited to c, because as far as we know all information requires a carrier - and, as far as we know, the fastest carrier is light. As I understand it sending information at speeds greater than the speed of light would violate causality.

Imagine that there is a bomb in LA that just went off. Jack Bauer finds a way to make his PDA use quantum entanglement to tell this to Washington before they would be able to detect the event any other way. If some horrendous female actor, err, computer analyst found a way to disarm the bomb before Washington would receive a signal traveling at c from LA and transmit the data back it could get there before either the bomb went off or Jack sent the first message.

Of course if the bomb never went off Jack would have never sent the first message, and the universe would implode. But it would probably get good ratings - so all is well.

Someone please correct any injustices I've just done to physics.

Re:Misinformative

[FallOfDay]

C+ would only violate causality if it changed an aspect of known history. Unknown/unviewed history is still in a superposition, therefore can be altered so long as it doesn't affect what we already know! :D

Re:Misinformative

[Anonymous Coward]

How do you respresent information in a non-physical way?

Re:Misinformative

[4D6963]

Imagine that there is a bomb in LA that just went off. Jack Bauer finds a way to make his PDA use quantum entanglement to tell this to Washington before they would be able to detect the event any other way. If some horrendous female actor, err, computer analyst found a way to disarm the bomb before Washington would receive a signal traveling at c from LA and transmit the data back it could get there before either the bomb went off or Jack sent the first message.

No? When the bomb would have exploded and that Jack would instantaneously inform Washington, then no matter what they would do in Washington, no matter whether they'd do it at the speed of light or instantaneously, it wouldn't change a thing.

Can you explain me how on Earth could they prevent anything this way? Unless you can send information back in time, which what you says must imply..

Re:Misinformative

[Cheesey]

This all comes from an argument I had years ago about quantum entanglement. I'd heard that two entangled particles could affect each other at any distance, and I thought that maybe this could be used for instantaneous communication. Physical objects would be involved at both ends, but the actual information would move by some weird entanglement magic rather than being carried by a physical thing.

But apparently not! In order to actually make use of entanglement for communication, you need a conventional communication channel as well. That means you could use entanglement to send data secretly, but you can't use it to circumvent the speed of light.

Re:Misinformative

[AndersOSU]

Ok, I'm not an expert at this, so what I say may very well be wrong, but I'll give it a shot.

How do you define present, or more to the point now or instantaneous? It may sound like a stupid question, but it's a tad tricky when you worry about relativity. I think that it is generally thought that something is happening now when light traveling from the event reaches the observer.

Which means that if you send information faster than the speed of light, that information gets there before the event actually happened. In other words, you sent the info back in time.

Mind you, this is all "as I understand it," and I'd love to have someone more knowledgeable throw their hat into the discussion.

Re:Misinformative

[4D6963]

I think that it is generally thought that something is happening now when light traveling from the event reaches the observer.

Now that's bullshit, when we look at galaxies 13 billion ly away we don't say that we see them as they are now but as they were 13 billion years ago.

That whole Jack Bauer example thing is like saying, "if person A farts, but that by some magic person B that stands 10 feet away instantly finds out that A has just farted while the smell hasn't reached his nose yet, and that by the same magic he instantaneously orders A not to fart, the fart wouldn't be released at all and it should violate the law of causality."

Which means that if you send information faster than the speed of light, that information gets there before the event actually happened. In other words, you sent the info back in time.

That's utterly ridiculous. That means that the ping between any probe in the solar system should be of 0 milliseconds. And that means that any information going at the speed of light would actually be instantaneous. If you want to determine instantaneousness between say someone anywhere in the universe and yourself, ping him, then you guys could both have the clock giving the same time, instantaneously.

You have some awful misconceptions about relativity and all that. Maybe you should talk about it in sci.physics, they're good at explaining things when you're confused.

Re:Misinformative

[AndersOSU]

Alright, you are forcing me to do the unthinkable on slashdot (the nuclear response if you will,) I'm going to quote and site a source.

I'm looking at my copy of A Brief History of Time by Stephen Hawking. It seems that I've generally F'd up the simultaneity issue. But that isn't really the interesting portion. He does however equate faster than light travel with time travel. I'm going to quote a portion of chapter ten now.

...What most of these authors don't seem to realize is that if you can travel faster than light, the theory of relativity implies you can also travel back in time, as the following limerick says:

There was a young lady of Wight
Who traveled much faster than light.
She departed one day,
In a relative way,
Add arrived on the previous night.

The point is that the theory of relativity says that there is no unique measure of time that all observers will agree on. Rather, each observer has his or her own measure of time. If it is possible fr a rocket traveling below the speed of light to get from event A (say, the final of the 100-meter rave of the Olympic Games in 2012) to event B (say the opening of the 100,004th meeting of the Congress of Alpha Centauri), then all observers will agree that event A happened before event B according to their times. Suppose, however, that the spaceship have to travel faster than light to carry the news of the race to the Congress. Then observers moving at different speeds can disagree about whether event A occurred before B or vice versa. According to the time of an observer who is at rest with respect to the earth, it may be that the Congress opened after the race. Thus this observer would think that a spaceship could get from A to B in time if only it could ignore the speed-of-light speed limit. However, to an observer at Alpha Centauri moving away from earth at nearly the speed of light, it would appear that event B, the opening of the Congress, would occur before event A, the 100-meter race. The theory of relativity says that the laws of physics appear the same to observers moving at different speeds.

This has been well tested by experiment and is likely to remain a feature even if we find a more advanced theory to replace relativity. Thus, the moving observer would say that if faster-than-light travel is possible, it should be possible to get from event B, the opening of The Congress, to event A, the 100-meter race. If one went slightly faster, one could even get back before the race and place a bet on it in the sure knowledge that one would win.

Re:Misinformative

[4D6963]

if you can travel faster than light, the theory of relativity implies you can also travel back in time

Sure, except that it doesn't apply to our case, since communication by quantum entanglement, if it was possible, would be instantaneous, not because it would go at an infinite speed, but because it would be instantaneous. In other words, it wouldn't go faster than light, it would only be instantaneous, and therefore it wouldn't go back in time.

Think about the game Nabercular Drop or Portal, when you go through a portal, you keep going at the same walking speed, even if you suddenly move by a hundred yards. In other words, the information Jack Bauer would send wouldn't go faster than light at any point, it would only be instantaneously transmitted.

Re:Misinformative

[AndersOSU]

Ok, so Mr. Hawking says, "if you can travel faster than light, the theory of relativity implies you can also travel back in time." Would you consider instantaneous to be faster than, slower than, or equal to the speed of light? If such a thing were possible it might appear to an observer moving with the information that he is moving at sub-light speed. But it would appear to an observer stationary with respect to the event to be superluminal (and they'd both be right).

If instantaneous is in fact faster than the speed of light, and traveling faster than the speed of light allows time travel, then doesn't it make sense that if you can send information faster than the speed of light you can also send information back in time?

The whole point of relativity is that time isn't absolute - it is relative. If observer Jack Bauer in LA sees a bomb go off, and sends an instantaneously (faster than c) to DC observer B traveling away from DC at relativistic speed would see DC receive the message before the bomb went off (and he'd be no less correct than Jack). If observer B sees DC get the message that a bomb went off and can send information instantaneously he could send a message back to Jack, even before Jack sent the original message.

This is a big part of why our current understanding of physics precludes superluminal travel and communication; if you allow superluminal communication you allow causality violations.

Now, I don't know what game you're talking about, and now that I've gone ahead and looked it up, if you want to refute me you'll have to find a reputable source. If you don't understand, either re-read the Hawking excerpt, or find another authoritative source.

Re:Misinformative

[4D6963]

Would you consider instantaneous to be faster than, slower than, or equal to the speed of light?

Slower, much slower, like 0.00 meters/second actually. If it was possible to communicate using quantum entanglement, it would consist of rougly having a pair of photons in two distant places, and when the state of one would be changed the state of the other would instantaneously follow. So you see, there's really no speed involved there.

The whole point of relativity is that time isn't absolute - it is relative. If observer Jack Bauer in LA sees a bomb go off, and sends an instantaneously (faster than c) to DC observer B traveling away from DC at relativistic speed would see DC receive the message before the bomb went off (and he'd be no less correct than Jack). If observer B sees DC get the message that a bomb went off and can send information instantaneously he could send a message back to Jack, even before Jack sent the original message.

I hate to sound like my girlfriend, but you don't listen. Read again my fart analogy.

if you allow superluminal communication you allow causality violations

Sure, if you make a wave or anything else go faster than light, because then it goes back in time. It's not the case of our quantum entanglement example. The point is, if both DC and Jack Bauer synchronize their clocks to make sure they both got the same time while Jack is in LA, then when the bomb would explode at time 0, and that Jack sent his quantum message at time 5 (let's say milliseconds), DC would get Jack's message at 5 ms, and the direct information (let's say the gamma burst from the bomb) that the bomb exploded would come to them at 17 ms, and no matter what they would do at DC, even if they sent back a message at 6 ms, it would still be received by Jack 6 ms after the bomb exploded. That's because, it would be instantaneous.

I'm not making anything up, quantum entanglement is supposed to be instantaneous, and not "go at an infinite speed and go back in time". No. Instantaneous. And I don't think that it's accurate to say that in relativity there's no such thing as simultaneousity, even if time doesn't always flow at the same speed and in the same direction, you still can sync your clocks even if one goes back in time.

If you don't understand, either re-read the Hawking excerpt, or find another authoritative source.

lol, I have nothing to understand. I don't mean to sound like a dick, but well you're kind of the one who has to understand that what we're talking about here (communication over quantum entanglement, if it was possible) wouldn't go back in time because it doesn't go at any speed, but that it's instantaneous. You can misquote any nobel prize you want, that won't cut it ;-)

Re:Misinformative

[AndersOSU]

Ok, if information travels from point A to point B faster than were possible with light, then that information is traveling superluminally. It doesn't matter if no physical particle actually moved, the information still has.

Your clock example is telling, you don't incorporate relativistic effects, which is necessary to understand how superluminal = timetravel.

Imagine we have three clocks and synchronize them. Clock A1 stays in LA, Clock A2 travels to DC, where it remains, and clock B is traveling so that when it reads 0.00 it is over DC traveling away from LA. Note that clocks A1 and A2 will always be in agreement because they are not moving relative to one another.

A1 and A2 agree that a bomb went off (event 1) at 0.00. A1 sends a signal instantaneously to A2. When A2 receives this message it broadcasts via radio a confirmation. This confirmation is event 2.

Now some calculations. Since observer B is moving at 0.8c the Lotentz Factor is 2.236. Now, LA and DC are approximately 4000km apart. If we use the following coordinates x=0 for DC, and x=-4E6 (meters) for LA we find that according to observer B who is at DC traveling at 0.8c event 1 happens at 2.236*[0-(0.8c*-4E6)/c^2] = 0.0238s and event 2 happens at 0.00. It should be clear that if observer B could send a message instantaneously to LA after event 2 it would get there 0.0238 seconds before event 1 occurred. This is time travel and a causality violation.

I know you aren't making anything up, but you are misunderstanding sci-fi to be real physics. You might claim to not have anything to understand, but you are misunderstanding plenty.

Re:Misinformative

[4D6963]

God, you're so thick :-)

First of all, event 1 doesn't *happen* at 0.0238s to observed B, but it is *observed* at 0.0238s. Observer B would be stupid if he assumed that because he observed it at 0.0238s it means it happened at 0.0238s. And if someone at LA sent him a message at 0.0, and that he sent one back at 0.0, then yeah obviously it would all happen before observer B would *observe* the explosion, but it wouldn't happen before the explosion would actually happen.

Ok, if information travels from point A to point B faster than were possible with light, then that information is traveling superluminally. It doesn't matter if no physical particle actually moved, the information still has.

God, no, just no. From the quantum entanglement article (since that's what we're talking about, although as we said it cannot be used to actually trasnmit information) : "As a result, measurements performed on one system seem to be instantaneously influencing other systems entangled with it.". If we had to take FTL considerations in account, then it wouldn't seem to happen instantaneously. I mean, what's so hard to understand, instantaneous doesn't mean infinite speed. If you could teleport yourself from here to the moon in a tenth of a second, it would NOT mean you went faster than light (because if you did you would have felt quite some acceleration). That's the idea, there's no speed involved, therefore no going back in time.

you are misunderstanding sci-fi to be real physics

Well it's easy to claim that when we're talking about something that's not possible in the first place.

you are misunderstanding plenty

Absolutely not :-)

Re:Misinformative

[AndersOSU]

Well, one of us it thick.

I'm guessing it is the one who has no understanding of relativity.

There is no preferred reference frame. If Observer A says event 1 and event 2 are simultaneous he's right. If observer B says event 2 happens before event 1 he is also right.

I'm done with this, if you wish to remain willfully ignorant you are free to do so - I'd ask that you not make yourself look like an idiot by spouting off horrible misrepresentations of physics, but I fear that is a lost cause. If you want to know how the universe actually works read up on relativity. A Brief History of Time is a solid read, even if you're incapable of understanding mathematics as well as physics.

Re:Misinformative

[4D6963]

I'm done with this, if you wish to remain willfully ignorant you are free to do so - I'd ask that you not make yourself look like an idiot by spouting off horrible misrepresentations of physics, but I fear that is a lost cause

That was uncalled for, but same to you.

Re:Communication a problem

[Ihlosi]

4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009.

Whoa, I didn't know that these things made 0.1c ...

Wait ... they don't. I think you meant "in later 12009".

Re:Communication a problem

[$RANDOMLUSER]

> ...only has enough fuel to last until 2020ish

Momentum is forever. I think you're talking about "battery life".

Re:Communication a problem

[Anonymous Coward]

If I recall my particle physics correctly, the way ATLAS at the LHC will be detecting gravitons is via their leptopic decay products, and regard that as the optimal way. Is your approach anything like this - if so, how would that be separable from the Interstellar medium at *any* distance by this "graviton detector"?

I'd like what you're saying to be true, but I'm having a hard time beliving it.

+2 Interesting!? Mod Parent Down

[physicsnick]

it takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009.

Voyager 1 will take on the order of several hundred thousand years to reach Alpha Centauri.

The traditional explanation for this is that the graviton can only travel at the speed of light and as such will take 10 minutes to travel from one particle to the other, so far so good.

The 'traditional' explanation? Gravitons are hypothetical at best, and currently mathematically useless. Quantized force mediators do not need to "intercept" a moving particle at a distance; they are virtual, and there are infinitely many of them in all directions.

By changing the mass of the ball (simple enough to do with a powerful laser)

This is all nonsense. Even if this were true, your probe is also receiving gravitons from every other atom in the universe. The effect of varying a "ball of mass" would not even be measurable. Just because a sizable block of text with "sciency words" is posted doesn't mean it's meaningful, and certainly doesn't deserve mod points. Please mod parent down, and please read things before giving points!

Re:+2 Interesting!? Mod Parent Down

[Joohn]

So what are you guys saying, is he dead wrong? Does gravitation in fact move in the speed of light and is it thus theoretically impossible to construct an "instant" communication device using gravitation? I'm just curious and find this more interesting than the obvious errors in his post.

Re:+2 Interesting!? Mod Parent Down

[Cyberax]

Yes, gravitation moves at the speed of light. That's why you get gravitomagnetic (http://en.wikipedia.org/wiki/Gravitoelectromagnet ism) which occur when two moving bodies gravitationally interact with each other.

Re:+2 Interesting!? Mod Parent Down

[khallow]

I glanced at Voyager 1's speed. It's going roughly 17 km/s. That's a bit more than 1/20,000th the speed of light. So it can travel as far as Alpha Centauri currently is in under 100,000 years. A lightyear is long, but not that long when you start talking of hundreds of thousands of years in which to do your traveling. I don't have anything redeeming to say about the grandparent.

Re:+2 Interesting!? Mod Parent Down

[khallow]

It hasn't been directly observed. Experiment has strong agreement with general relativity which implies that gravitation acts at the speed of light.

Re:+2 Interesting!? Mod Parent Down

[Cyberax]

It has been measured, see http://www.arxiv.org/abs/gr-qc/0501001 . The result of this measurement - speed of gravity is between 0.8c and 1.2c, which is consistent with gravity propagating at 1c.

Re:+2 Interesting!? Mod Parent Down

[khallow]

You quote the study that questioned the original measurement. Apparently, the relativistic model in question was improperly used by the wouldbe measurers.

Re:+2 Interesting!? Mod Parent Down

[Anonymous Coward]

How else are we supposed to get subspace communications up if we don't play with massive balls and lasers? I miss Thor.

Re:+2 Interesting!? Mod Parent Down

[Cyberax]

Sorry, I could not find the link on the original study. In any case, indirect observations (like perihelion precession of Mercury) also confirm that gravity moves at about 1c.

Re:+2 Interesting!? Mod Parent Down

[khallow]

Those measurements confirm general relativity, which as I point out, requires that gravity interacts at the speed of light. While my statements no doubt confirm the rumors that I revel in pedantry, I still must point out that no direct observation has confirmed that gravitation acts at the speed of light. I imagine this will change in the next decade or two, but until then, I'm smugly sitting back.

Also, it's pretty cool how we can cite directly online the papers in question (or at least papers that refer to the paper in question). Definitely turning out to be a Brave New World here.

Re:+2 Interesting!? Mod Parent Down

[Anonymous Coward]

gravitons travel 100x spped of light

Re:+2 Interesting!? Mod Parent Down

[Cyberax]

Actually, we can argue on what constitutes a 'direct' measurement :)

But I mostly agree with you, though I believe that it's very unlikely that gravitation will be propagating at more than 1c.

Bullshit

[rumith]

And the signature is physicsExpert?! Man, he has NO understanding of particle physics, and his post is completely misguiding.

Re:Communication a problem

[Captain Hook]

I was thinking in terms of thrusters to be able to align the probe towards earth/anything interesting that might be out there such as a Vogon Construction Fleet.

Re:Communication a problem

[physicsnick]

If I recall my particle physics correctly, the way ATLAS at the LHC will be detecting gravitons is via their leptopic decay products, and regard that as the optimal way.

You're thinking of the Higgs boson. We are nowhere near approaching the level of technology required to detect gravitons, and the mathematics they give rise to doesn't even work. The only real reason we have to believe they exist is because the other forces also have quantized mediators.

Forget...

[ilovegeorgebush]

A year already?! I remember the launch, but why is it so easy to forget these awesome achievements. Some, perhaps, take for granted what it takes to get something so fragile as 'New Horizons' to get into space...Very impressive picture too. What an age we live in!

Re:Communication a problem

[yoprst]

The explanation is in fact that the gravitons do not move at the speed of light but instead are exchanged instantaneously
/bangs his head against a wall for 30 minutes...
Let's strip you of your academic credentials along with a dude who proposed stripping of academic credentials from global warming sceptics
/returns to banging his head against a wall for another 30 minutes...

Re:Communication a problem

[Jzor]

It will be ok if it runs out of thruster power. I'm sure it will run into some sentient mechanical life forms out there that will repair it so it can continue on its mission to learn all that is learnable and transmit it back to the creator.

heh

[Moby Cock]

Pluto Probe Snaps Jupiter Pictures

Doctor Manhatten Outraged!

Re:heh

[Anonymous Coward]

From JPL's "Basics of Space Flight"http://www2.jpl.nasa.gov/basics/bsf1-1.html :

Most planets rotate in or near the plane in which they orbit the Sun, again because they formed, rotating, out of the same dust ring. The exception, Uranus, must have suffered a whopping collision that set it rotating on its side.

*snicker*

Re:Communication a problem

[tgd]

Somehow I suspect the extent of his scientific credentials is a copy of the Starfleet Technical Manual with pages that are strangely stuck together, and a tattered Burger King hat hung from a nail in his parents' basement.

MOD PARENT UP!

[Anonymous Coward]

Oh wait... It already is +5 funny... Must be all that gas getting to me

Another dismissal for erroneous points

[FallOfDay]

...this means that the particles must 'know' where each other are going to be in 10 years time. This is quite frankly ridiculous!

You're still thinking in three spatial dimensions plus one of time. Start adding extra dimensions to Einstein's 4D & things aren't so ridiculous - extra dimensions will discount, not time itself but, the effect of time. Why do you think 10D & 11D Superstring/M theories have been postulated?

In this way the rule limiting the exchange of information is kept intact and the rules of physics remain unchanged.

Only in Euclidean space. In quantised spacetime, the data is there instantaneously & exchangeable. Any data that isn't exchanged until via Euclidean space is in a superposition, until viewed, and is available for exchange in methods not reliant on Euclidean space.

Re:What a waste

[Anonymous Coward]

We should be spending the money on actually going there.

NO! This money should go to fattening up the poor so when they suffer from their obesity we can cure that as well!

Clinton/Reno 2008!

Er one thing

[KKlaus]

Good post, and its always nice to see someone who has real science's back, but as far as I know in no theory of gravitons are there an infinite amount in all directions, unless of course we take the universe to be infinite, in which case there is an infinite amount of everything in all directions (assuming no strange emergence of uniformity that we are unaware of). Anyhow, like I said, way to torture to death someone that knows less than you :D.

probe

[hachete]

when does it get to probe Uranus?

Thankyou, thankyou. I'll be here all week. Try the chopped liver.

Re:probe

[Anonymous Coward]

>>> Thankyou, thankyou. I'll be here all week

Then I'm so glad it's Friday.

Re:Communication a problem

[Frumious Wombat]

Only if a bored starship commander doesn't use it for target practice first.

That's Nothing

[Anonymous Coward]

Wait till you see the probe on Uranus.

From Wiki, and I know I've read similar on NASA...

[silentounce]

but I couldn't find it.
 
"Voyager 1 is not heading towards any particular star, but in 40,000 years it will be within 1.7 light years of the star AC+793888 in the Camelopardis constellation."
 
From http://www.daviddarling.info/ :
"An earlier planned route past Neptune would have resulted in the probe coming within 0.8 light-years of Sirius in just under 500,000 years from now - easily the closest and most interesting foreseeable stellar encounter of the four escaping probes. However, the Neptune flyby trajectory actually chosen (the "polar crown" trajectory) means that the nearest Voyager 2 will come to any star in the next million years is 1.65 light-years when it passes Ross 248 in about 40,000 years."
 
From that quote it looks like it was originally planned to fly by a star. The same site has this to say about Voyager 1: "Thereafter, it will have a journey lasting almost 40,000 years before it passes the M4 red dwarf AC +79 3888 at the remote distance of 1.64 light-years (0.50 parsec)."

4 billion kilometers...

[yaohua2000]

New Horizons will be soon exactly 4,000,000,000,000 meters away from 134340 Pluto at 2007-01-19 18:49:08 UTC.

http://www.yaohua2000.org/cgi-bin/New%20Horizons.p l

Mac widget for tracking New Horizons: http://www.apple.com/downloads/dashboard/status/ma gicnumber.html

Mix Up ?

[gungh0]

So it was sent out to take Pluto pictures & they get Jupiter photos back ? I used to get that problem when I sent my films away to be developed, always getting back snaps of people I didn't take ! If your a fat sunbather in red trunks, I've probably got your photos. ;-)

APL???

[markhb]

What is this APL, and why are they named after a programming language with its own character set?

Re:Communication a problem

[Teancum]

I think he has mistaken the idea that Voyager will leave the solar system in 2009, as defined by the region of space where the solar wind is overcome with other stellar matter from the rest of the Milky Way, and presumably in the region of space roughly where the Oort Cloud is likly to be located at. At that point you could presumably suggest that it is in interstellar space and the gravitational influence of the Sun is insignificant compared to other objects in the rest of the Galaxy.

While that is in reality a major accomplishment in terms of having a human artifact leave the solar system, it is a far cry from being able to reach another star system, especially Alpha Centauri. Especially as Alpha Centauri is hardly in the plane of the ecliptic (where most of the planets are located at), requiring some very precise trajectory calculations that would have made the visit to the outer planets by Voyager too difficult to perform.

The primary mission of Voyager was to visit the gas giants of the Solar System, and it did that spectacularly. Anything else it has done or is doing now is incidental extra science, as we are now getting scientific measurements of the environment that is very far from the Earth.

As a matter of scale...

[argStyopa]

Just to give you a sense of scale for Jupiter, the Earth would fit nicely into the Great Red Spot (N/S dims of red spot are almost exactly the same as the diameter of Earth).

Re:As a matter of scale...

[BlackSnake112]

Jupiter's diet must be working. I was always told that three earths side by side could fit into the big red spot. n/s one, but three side by side.

Re:As a matter of scale...

[argStyopa]

Can't comment on the diet, but according to wiki:
12-14,000 km high by 24-40,000 km wide.

Earth is about 12,750 km diameter.

So yeah, at it's fullest you could fit 3 wide, but only the center one would fit completely widthwise.

Re:As a matter of scale...

[Tablizer]

Just to give you a sense of scale for Jupiter, the Earth would fit nicely into the Great Red Spot (N/S dims of red spot are almost exactly the same as the diameter of Earth).

I told you those corporate mergers would doom the Earth.

Re:Why pluto?

[WormholeFiend]

Because spying on the Mi-Go is more important

Re:Why pluto?

[Anonymous Coward]

Afaik, only abducting aliens has that kind of technology.

Re:Communication a problem

[khallow]

I calculate around 77,000 years (given 17 km/s which understates Voyager 1's speed). 17 km/s is faster than 1/20,000th the speed of light. So Voyager 1 travels one light year in under 20,000 years.

Re:From Wiki, and I know I've read similar on NASA

[Anonymous Coward]

-- No matter how many times you shake it, the last few drops are going in your pants.

One of the more useful things I have learned from Slashdot is that this is not actually true. Reach behind your nuts and press up and forward (you'll feel the base of your urethra under the skin). After that, one more squeeze and it's really all empty.

Re:Communication a problem

[khallow]

As previously mentioned these gravitons will instantly arrive at our deep space probe regardless of how distant it actually is, but will not act on it until some time later. The key part is that we have a graviton detector on our probe which measures the number of gravitons received.

You can stop now. Interacting with a graviton detector is an "action". Ie, if we use your model of interaction, the gravitons show up "immediately" and then interact with the graviton detector some time later. BTW, "immediate" is poorly defined. If an object is a light year away, then from a year into the past to a year into the future could be concurrent with our time. There's no obvious hypersurface of constant time in the presence of gravity and acceleration.

Just an Opinion...

[Thumper_SVX]

I'm really excited about New Horizons. It's a really exciting mission that almost didn't get the support it needed. If you do some Googling you can find out the full story about it.

Hell, I know Pluto isn't considered a planet... but that to me makes NH even more exciting. Pluto is a large KBO (Kuiper Belt Object) and as such has the potential to be a very early remnant of the formation of our solar system. As such, investigating this object and Charon, it's "moon" has the potential to teach us far more about the early existence of the solar system than investigating many other objects. To be honest, I'm MORE excited about a trip to a relatively unknown and uncharted object such as a KBO than I would be over the exploration of another planet (despite the fact that these are arbitrary designations at best)

The NEAR mission was fascinating for the same reason. It was investigation of a relatively unknown object and we learned far more about the nature of asteroids and other deep space objects during that mission than we ever thought possible. If NH even returns half of the information about Pluto that NEAR returned about the asteroid Eros then we will learn an incredible amount about our solar system, and maybe change a few models about solar system formation that might just change some minds.

Good show, NASA. Sometimes you're the butt of a lot of jokes, but there are times you manage some truly remarkable missions (the mars rovers for one) that increase our understanding of the universe and just really excite science geeks like me :)

Moo

[Chacham]

I still think Jupiter looks like a giant wood chip.

The linked picture is here.

2009?

[HangingChad]

t takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009.

If Voyager 1 is covering a million miles a day, that means an AU roughly every 90 days, a little less than 4 AU's a year. Being over 277,000 AU's to Alpha Centauri you'd be looking at close to 80,000 years. I'm too lazy to pull out a calculator and run the exact numbers.

Unless you physics experts invented some way to bend the time/space continuum or you've got a prototype for a working warp drive in your car, that trip will take a bit beyond 2009.

Just begging for the joke

[dsvick]

The headline made me think of a Mitch Hedburg type joke...

"Pluto Probe Snaps Jupiter Pictures"
Well then they F***ed up.

Re:Communication a problem

[ConceptJunkie]

Here in the lab...

Sorry, your imagination is not a lab.

pretty tough for this early ...

[joeyspqr]

you stole rucs-hacks coffee? that's just mean

Wha???

[Cervantes]

"Pluto Probe Snaps Jupiter Pictures"

Holy crap, they made another metric/imperial conversion error!

Re:What a waste

[Anonymous Coward]

We've spent billions over the past 40 years looking for a stinking microbe

And all we found was that Martian microbe that smells like daffodils.

Re:Communication a problem

[Anonymous Coward]

I can detect gravitons! I use a patented technique known as "letting something go".

Of course, this detector can be fooled by rotation and acceleration, but it works well most of the time.

All that distance...

[exp(pi*sqrt(163))]

...and they forgot to load the cameras up with colour film.

Re:All that distance...

[Thomas Henden]

Yeah, guess Nina Hagen isn't very happy about that...

Here's NASA's Reaction:

[Anonymous Coward]

Today the team released some of the early data and pictures, which are the first close-range shots of the giant planet since the robotic Cassini spacecraft passed that way in 2001.

"Yep. Still looks exactly the same. Ho Hum."

Re:Communication a problem

[sighted]

The chief scientist for the Voyager mission told me a couple of weeks ago that he guesses Voyager 1 is more like 10 years away from the heliopause, and talked at some length about the exploration of the solar system's boundaries. You can hear the conversation in this podcast.

Damn!

[Jugalator]

Damn, it's still there!

Those Jovians sure are persistent. :-(

Re:What a waste

[Anonymous Coward]

I think we should send a huge probe to Uranus.

DOH!

[Anonymous Coward]

New Horizons is now 3999565009 kilometers away from Pluto.

I missed it.

Re:Communication a problem

[AaronHorrocks]

Alpha Centuri is about 10 light-years away.
Thus it would take 10 years, not 4.

Re:Communication a problem

[Teresita]

"Alpha Centuri is about 10 light-years away. Thus it would take 10 years, not 4."

On the contrary, Alpha Centauri A/B is 4.395 light-years away, plus or minus 0.007 light-years. Wikipedia is your friend!

Re:Communication a problem

[AaronHorrocks]

I have a tendancy to trust onhand literature, than an online community where anyone can change the facts.

Re:Communication a problem

[Teancum]

Thanks for the link. What I find interesting is that the actual boundary of the heliopause is something that still is an area of significant investigation at the moment. I have heard all kinds of ranges in estimates regarding when Voyager would actually cross that threshold, with the date getting pushed back more and more as Voyager actually gets to the point they thought would be the heliopause. It also seems to be affected by things like the sunspot cycle and other solar activity (with an appropriate time lag due to the distances involved).

2009, I believe, was one of the earlier estimates given back when Voyager was still close to Neptune. What is cool is that real science is still happening with the Voyager spacecraft as it heads for the very frontier of the solar system, as the only way to do this sort of science is to get something "out there" in the first place.

Re:Communication a problem

[sighted]

Exactly. I think it's a lot of fun to watch such a basic piece of information - 'where is the edge of the solar system, anyway? - in the process of being discovered.