Slashdot Mirror
Computer Forensics to Help Solve Pioneer Mystery
Matthew Sparkes writes "Launched 35 years ago on Friday, Pioneer 10 was the first spacecraft to reach the outer Solar System and return pictures of Jupiter, closely followed by Pioneer 11. However, the twin Pioneer spacecraft drifted off course (see number 8) by hundreds of thousands of kilometres during their three-decade mission, and NASA eventually lost contact with them. An international team of scientists, including many amatuer hobbyists, are re-analysing the tracking and telemetry data in the hope of discovering the reason."
Only hundreds of thousands of miles? Thats not too bad given the size of the solar system.
Libertarian Leaning Political Discussion Forum.
are they imaging the hard drive ? recovering deleted data ?
from Google:
Computer Forensics is the use of specialized techniques for recovery, authentication, and analysis of electronic data when a case involves issues relating to reconstruction of computer usage, examination of residual data, authentication of data by technical analysis or explanation of technical features of data and computer usage.
As the article states: So if the direction of deceleration is towards Earth, then you might be able to consider the mystery solved and blame it on the process of collecting the data. But if the deceleration is towards the sun or another direction, we have an observation of an unknown effect in physics. If the latter is the case, I think the mystery is just starting to be understood--with a long ways to go and many more observations before we can consider it solved.
My work here is dung.
while it is possible that the explanation will be mundane--such as thrust from gas leakage--the possibility of entirely new physics is also being considered. http://en.wikipedia.org/wiki/Pioneer_anomaly
Strangest of all:
Data from the Galileo and Ulysses spacecraft indicate a similar effect
Libertarian Leaning Political Discussion Forum.
Dark Matter!
Seriously, though, how likely is it that the gravitational and orbital calculations were just not quite as precise when they did them 35 years ago?
Despite a highly rigorous formula for determining this stuff, I can imagine that there could have been a few unknowns that affected such an enormously complex calculation.
It will be relatively easy for them to find something in all that complexity that may possibly be to blame, then totally ignore the possibility that this really might be an unknown external influence.
Given that Gravity affects an object's momentum, in this solar system, and was used for acceleration by the Pioneer craft. Would not a simple calculation of finding how much gravity would be needed to cause the "drift"? Then the question could be asked, "What combination of bodies in the known space would cause this?"
Only hundreds of thousands of miles? Thats not too bad given the size of the solar system.
Yeah, but it's hundreds of thousands of kilometers.
[french guy]Sacre bleu!![/]
s/amatuer/amateur/
Heh. I think most of us here on Slashdot would want this anomaly to be due to new and k3wl physics rather than some mundane error. The Pioneer anomaly is one of, if not the most interesting unexplained observation I know of.
What about V'ger?
V'ger.
I suppose it would actually be P'neer, but that just doesn't sound right somehow.
Slashdot Burying Stories About Slashdot Media Owned
The Al-Quaida is behind this...They did it with the help of Iran...They are making this Solar system a dangerous place
there was a '0' where there should of been a '1'.
It would actually make sense to look for a single condition in the myriad of possible known phenomena. That's basically what Occam's Razor says. There's no sense in looking for a complex or radical solution until all of the simple possibilities have been exhausted.
This doesn't mean that I'm advocating ignoring re-investigating things from fairly basic principles, but at the same time I think that it would be foolish to immediately assume that something that we haven't yet had any notion of is the culprit. It would be pretty neat if the effect was something new, but you can't assume it's new until you've eliminated all of the other possibilities.
Do not look into laser with remaining eye.
However, the twin Pioneer spacecraft drifted off course (see number 8) by hundreds of thousands of kilometres during their three-decade mission, and NASA eventually lost contact with them.
This seems to imply that NASA lost contact because the spacecraft drifted off-course. AIU, they lost contact because the signals became too weak to be readable (due to distance and/or degradation of the RTG).
I love this story, it's been popping up every now & then ever since my first accepted Slashdot submission on the topic more than five years ago... it's really very interesting, even if (as seems likely) it turns out the be a missing factor or inaccurate measurement somewhere, rather than a Whole New Physics[tm].
I have a reletive who is a CSI guy. I get the impression that 95% of there work is dusting for prints where there was some petty theft then all the paperwork that involves. When there is a major crime they mostly gather the physical evedence then move on to the next crime scene, the tracking down of the suspects is left up to the Detectives. There job is specialized so they can't sit around trying to locate criminals since there is always another crime scene to be worked.
No matter where you go, there you are.
I've often wondered whether gravity is really exactly a one-over-r-squared phenomenon. I would think that between the curvature of space, strange hidden dimensions, dark matter and dark energy, that things would not be exactly Euclidean and that the exponent on the equation for gravity wouldn't be an integer.
IANAP, but as an engineer I've learned that so-called "constants" seldom are.
Two wrongs don't make a right, but three lefts do.
Captain Klaa is currently sought for questioning.
http://memory-alpha.org/en/wiki/Klaa
One useless man is called a disgrace; two are called a law firm; and three or more become a Congress. -John Adams, 1776
We are still in contact with the Voyager probes, and they have, at this point, traveled further out of the solar system than the Pioneer probes. Has the same anomaly been spotted in their trajectories too? That would be of great importance in weeding out possible phenomena.
It just fell off the back of the turtle and found its demise under legs of the elephants holding it!
No, they wanna be there when a nameless lackey reports the results of scouring sixty acres of woods, or of 36 hours of peering at and testing the insides of a vehicle. Then you say, "thanks", take the folder, and go issue pithy remarks to the suspect, who then caves. Then the music starts and you listen to old rock and pop tunes. You have done a good job! You are awesome-o!
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
So how is telemetry calculated? I don't know a great about astrophysics and the like, but surely position is relative to something? Is it at all plausible that some unknown factor in, for example, the solar systems movement accounts for this deviation and that pioneer has actually remained on course?
It seems to be a no-brainer that the most likely cause is gravitaional force from something we didnt know was there. Some kupier belt trash, comet that passed it years ago, who knows. I'm frankly surprised that these types of navigational issues were/are not expected .....
...that what you are talking about is the Pioneer anomaly. That is a well-known name, so when you didn't mention it, you got me thinking there was some other curiosity going on that I had missed.
Swedish plasma phys. PhD student; MSc EE; knows maths, programming, electronics; finance interest; seeks opportunities
Those black monoliths are distracting and meddlesome.
Pentium FDIV bug?
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Sounds like something I'd pick up at the Indian joint down the street.
Best Slashdot Co
Really, are you completely sure about that ? I mean even though Quincy was only a medical examiner he managed to solve a lot of the cases, Mrs Marple is only a little old lady with no connection at all to the police and yet they're more than happy for her to do most of their work for them not to mention Poirot who has a similar arrangement where he can direct the actions of the police almost totally. Judge John Deed may well be a judge but that can't stop him solving cases.
I really can't believe you seem to be suggesting that these roles are really strictly delinated and that in real life it's not exactly like it's portrayed in the programs.
So you mean we probably shouldn't have carved *all* our names in the *same* RTG boom with the dremel?
We weren't supposed to do that?
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
stopped smoking Indian joints?
Clear, Dark Skies
This is one of the "clues" that is being used to propose Modified Newtonian Dynamics or MOND. Current understanding of MOND actuallly brings it into play farther out than this but in some versions, the effect "scales" with distance. MOND
There was a link to this place when I posted that. I blame the comment filter.
Best Slashdot Co
What are the chances it merged up with an alien life form, and together they are charting their own course?
Have you read my journal today?
Hanging out at the planetarium growing up, I got exposed to a lot of notions of the physical universe.... One that stuck was the notion that the universe is like an expanding balloon; this model answered the red shift problem. If you look from a point to any other point as the baloon inflates, its all moving away from you. Now the black hole theory with this expansive universe; if you hold a stationary pin to the balloon while it expands, expansion occurs at a different rate about the head, and effectively the space gets bent about the head. This is true for any mass or gravity well. The other analogy was steel ballbearings on a sheet of plastic wrap; the bend the surface about them, and this is why light seems to bend about a gravity well. If you take these analogies and apply them to a space vehical zooming away from a gravity well, then linear and vector graphics do not apply in predicting the course. Space is bent, and as you get out from the divot to the surface, your distance in not constant. It would look like you're speeding up to the observer, and also not going the direction you had planned.
Seems obvious to me, but I'm not a physicist.
/\/\icro/\/\uncher
--
.nosig
I think we are really looking at space not actually being a void but has gases, matter, and a drag coefficient. If the ships hit gas bubbles it would also slow down the craft.
The rules of space are different from the rules of the earth and should be dealt with in the same matter.
Our scientist do not truly know the G forces or actual size to the decimal of any planets beyond mars, the theory of how much thrust would it take to break orbit was off a few degrees, This is also a possible account of what happened.
I would say lets learn more about space but no one in congress is interested enough to care!
TSS
0.5 miles per hour * 20 years = 100,000 miles.
Voyagers have been flying for 30 years, so YES, the attitude stabilizer of a probe can have a huge freaking impact on its position in 30 years.
When you're plotting a graph of experimental data, there is the concept of an "error bar" - you make the point on the graph smeared out to reflect the inaccuracy of your measuring tool. In the case of the Voyagers, the error bars are larger than the observed Pioneer anomaly, so there isn't any way of using that data. The error bars are sometimes called "noise", because it's not "signal". So, if the effect is small, it can be "lost in the noise". In other words, you can't see the tiny deviation because of the huge (comparative) error in measurement.
My amazing wife - Artist, Author, Philosopher - Laurie M
Dark matter apparently has a huge gravitational impact on the behavior of galaxies and clusters of galaxies. If this turns out to be real and not an artifact of the data, it could give us a clue about which way we should be looking for this mysterious stuff.
Clear, Dark Skies
The Kuiper Cliff (#10) fascinates me. I'd not heard about that, but I was aware that a peculiar wobble in the orbits of all the planets suggested that a very large object was orbiting in the distance. The Twin Sun theories are very interesting, especially in how they link to cyclical comet clusters bombarding the earth into the stone age every few thousand years. We're due right now, according to some.
I also find #12 interesting. (The not-so-constant constants). At first glance, it appears to fit well with the idea that there are various levels of energy 'density', providing different levels of reality in which beings can exist. One idea posits that UFOs are visitors from a higher level of reality which is constantly around us.
#13 is funny. (Cold Fusion), --Largely because the editor used pissy wording to describe Pons & Fleischmann's work, probably because he was numbered among those who scoffed at the pair and would prefer to believe that it was somehow the two researcher's faults that he wasn't smart or brave enough to give them more credit.)
And of course #4. (Homeopathy). The solution to accepting that homeopathy works links nicely with many other theories considered bunkish, but which also "somehow" carry weight. Basically, it's not the molecule as much as it is the energetic vibration of the molecule which carries information, and which responds to the body. This is Chi in a nutshell; a whole layer of energetic reality which affects pretty much everything in our universe, upon which astrology, awareness and the spirit, (among other things) are based, but which nobody wants to look at. Except the dark corners of the military, which know how to manipulate aspects of it. CFL's produce how much radio interference? More than cell phones and microwaves and TV's? Hmm.
-FL
Technically to get the scales involved you should solve for acceleration in 400,000 km = 1/2*a*t^2, and maybe compute the force with F = m_spacecraft*a, and then maybe to help visualize represent it as the force produced by the weight of some speck on Earth through F = m_speck*g.
And no need to beat him with the meaning of error bars if he's looking for intuition why those *particular* error bars are so large.
Your comment came up as the 2nd hit on a google search of p'neer. http://www.google.com/search?q=p'neer&ie=utf-8&oe= utf-8&aq=t&rls=org.mozilla:en-US:official&client=f irefox-a
Here's a link to the cannonical paper on the issue: http://arxiv.org/abs/gr-qc/0104064
Also, if you're interested, and in the New York area, some of the scientists who've been working on this are speaking at the Hayden planetarium in a few weeks: http://haydenplanetarium.org/programs/asimov/
Just to give a feel for what obsessive level of detail we're dealing with, here's a list of the possible causes considered in the paper above. The numbers after each listing are the bias and uncertainty in units of 10^-8 cm/sec^2. Listings with only one number only have an uncertainity, not a bias.
1 Systematics generated external to the spacecraft:
a) Solar radiation pressure and mass +0.03 ±0.01
b) Solar wind ± 10^-5
c) Solar corona ±0.02
d) Electro-magnetic Lorentz forces ± 10^-4
e) Influence of the Kuiper belt's gravity ±0.03
f) Influence of the Earth orientation ±0.001
g) Mechanical and phase stability of DSN antennae ± 0.001
h) Phase stability and clocks ± 0.001
i) DSN station location ± 10^-5
j) Troposphere and ionosphere ± 0.001
2 On-board generated systematics:
a) Radio beam reaction force +1.10 ±0.11
b) RTG heat reflected off the craft -0.55 ±0.55
c) Differential emissivity of the RTGs ±0.85
d) Non-isotropic radiative cooling of the spacecraft ±0.48
e) Expelled Helium produced within the RTGs +0.15 ±0.16
f) Gas leakage ±0.56
g) Variation between spacecraft determinations +0.17 ±0.17
3 Computational systematics:
a) Numerical stability of least-squares estimation ±0.02
b) Accuracy of consistency/model tests ±0.13
c) Mismodeling of maneuvers ±0.01
d) Mismodeling of the solar corona ±0.02
e) Annual/diurnal terms ±0.32
Because when I read that headline, I was wondering how computer forensics were being used with Lewis and Clark or the like. Maybe that's just me.
You all have Oo.o and Firefox, so get World Wind.
Voyager 1 has already been measurably deflected by the gravity of an TNO (Trans Neptunian Object). i.e. the unknown gravity field in the outer solar system adds to the uncertainty of forces acting on the space craft.
The New Horizons probe headed to Pluto is spin-stablized during the "sleep" period of its journey. Thus, I wonder if it can help test this anomoly.
Table-ized A.I.