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Space Science

More Spacecraft Velocity Anomalies 339

ZonkerWilliam recommends a bulletin from the American Institute of Physics, which discusses a study noting that recent spacecraft, such as NEAR, appear to display velocity anomalies much like those seen in Pioneer 10 (which were observed beginning ten years ago). The anomalies amount to up to 13 mm/sec., with a measurement accuracy of 0.1 mm/sec. Quoting: "A new look at the trajectories for various spacecraft as they fly past the Earth finds in each case a tiny amount of surplus velocity. For craft that pursue a path mostly symmetrical with respect to the equator, the effect is minimal. For craft that pursue a more unsymmetrical path, the effect is larger."
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More Spacecraft Velocity Anomalies

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  • spooky (Score:5, Funny)

    by superdana ( 1211758 ) on Friday February 29, 2008 @12:02PM (#22600638)
    Does anyone else feel like they just read the first console in an old Bungie game? We should probably be arming ourselves.
    • Re: (Score:3, Funny)

      by hcdejong ( 561314 )
      Well, to be fair, there was no mention of "war was beginning", so we're probably safe.
  • by yotto ( 590067 ) on Friday February 29, 2008 @12:02PM (#22600642) Homepage
    It's actually 13 inches per hogshead, which is what they expected.

    No problems here.
    • Awesome precision (Score:4, Interesting)

      by DancesWithBlowTorch ( 809750 ) on Friday February 29, 2008 @12:39PM (#22601200)
      I'm amazed that they can apparently measure the speed of spacecraft that's millions of kilometers away, to a precision of 10e-4 m/s. How do they do this? I imagine it must be some sort of interferometry. Still, awesome. If only cruise control (with automatic distance control) was this accurate. :-)
      • Re: (Score:3, Funny)

        by pnewhook ( 788591 )

        Even if you had hyperaccurate cruise control, you'll still get some jackass yammering on a cellphone cutting you off or slamming into you.

      • Re:Awesome precision (Score:5, Informative)

        by Detritus ( 11846 ) on Friday February 29, 2008 @12:57PM (#22601502) Homepage
        The range isn't an issue, it's how accurately they can measure doppler. The standard technique is to transmit a special signal to the spacecraft, which retransmits it to the Earth, like an RF mirror. This allows them to use extremely stable ground-based oscillators, like Hydrogen masers. This signal can also be modulated with a PN code to allow precise range measurements.
        • What? They can measure the position AND momentum without changing the phase-shift impulse on their Heisenberg compensators? Don't tell Geordi
    • by frankie ( 91710 ) on Friday February 29, 2008 @01:34PM (#22602100) Journal
      Come on already! How many fatal flaws have to be revealed before "scientists" will admit that the Theory of Gravity is invalid?

      Intelligent Pushing [google.com] describes this behavior quite easily. It's obvious that GSM would apply more appendage force to non-equatorial motion. Things going in odd directions are simply more fun to play with. Duh!

      I'm surprised the electric universe otaku [slashdot.org] haven't jumped in to claim credit for this yet.
      • by Walt Dismal ( 534799 ) on Friday February 29, 2008 @02:00PM (#22602498)
        Phooey. This clearly proves existence of the ether, a theory I've supported since I was a child in grade school, 108 years ago. Michelson-Morley my ass. And Xenu particles can travel faster than light, too. Modern physics is all invalid. I shall prove you all wrong with my free energy machine, controlled by Windows Vista, Crackpot Edition.
      • Re: (Score:3, Interesting)

        by SteveWoz ( 152247 )
        The scientists have already admitted such, to some extent at least. It would help if we had any sort of clue as to 'what' gravity is. There is active research to determine the rate of propogation of gravity. If it were at the speed of light, the earth's orbit would double every 1800 years. With quasar-assisted measurements, the best estimate now is that gravity propagates at 20 billion (2 times 10 to the 10th) the speed of light. Our concept of gravity was taught as being instantaneous, and this speed is fa
  • by splutty ( 43475 ) on Friday February 29, 2008 @12:02PM (#22600648)
    They're getting sick and tired of these slow things and finally got out and started pushing.

    Must be it.

    Or possibly dark matter... ;)
  • Hmmm..... (Score:5, Interesting)

    by TripMaster Monkey ( 862126 ) on Friday February 29, 2008 @12:03PM (#22600656)
    Could this anomaly possibly be explained by dark matter [blogspot.com]?
    • Re: (Score:3, Interesting)

      by Yetihehe ( 971185 )
      Or maybe by time running out of universe [slashdot.org]. If there is time running out, then everything would speed up (like expansion of universe and satellites).
      • Re:Hmmm..... (Score:4, Insightful)

        by Leperous ( 773048 ) on Friday February 29, 2008 @12:29PM (#22601022) Homepage
        Unlikely. If "everything [were to] speed up" that would presumably include us, and hence we wouldn't be able to observe any difference. Plus, if this was happening, it should be more apparent faster moving objects, such as particles whizzing around particle accelerators at relativistic speeds - but it's not.
      • by kestasjk ( 933987 ) on Friday February 29, 2008 @12:40PM (#22601210) Homepage
        Lets postulate an entirely new field/form of matter/universe to explain this phenomenon!
      • by Magada ( 741361 )
        Maybe what they're measuring is the amount by which the Earth got fatter around the waist since they last looked?
        • Re:Hmmm..... (Score:4, Informative)

          by macslas'hole ( 1173441 ) on Friday February 29, 2008 @01:16PM (#22601790)
          The Earth does indeed gain mass continuously from in-falling space dust, captured solar wind, etc., and as a consequence of GR, our clocks should be getting slower over time relative to distant satellites. However, I would think that the effect is not sufficient to account for the observed velocity discrepancy. I am just a lowly programmer, but I would be very surprised if those physicists have not taken this into account or discounted this accordingly.
    • by sm62704 ( 957197 ) on Friday February 29, 2008 @12:19PM (#22600860) Journal
      Could this anomaly possibly be explained by dark matter [blogspot.com]?

      Maybe, but I think it's more easily explained by dork matter [slashdot.org].

      There is no dork side of the moon. As a matter of fact it's all dork.
    • Re: (Score:3, Interesting)

      Or, there could be some more conventional gravitational source in the vicinity, one that hasn't yet been detected by other means. It doesn't take a hell of a lot to create an anomaly of that magnitude, and if an object were fairly massive it could still be quite far away.
      • More likely than not, they've simply missed when it comes to measuring detected gravities...remember, space is curved.
        • Re:Hmmm..... (Score:5, Insightful)

          by Teancum ( 67324 ) <robert_horning&netzero,net> on Friday February 29, 2008 @03:24PM (#22603602) Homepage Journal
          One thing you must remember is that this is being published in scientific journals, not just some back page of your local newspaper. If there is one thing scientists do like to perform, is showing that somebody else missed a basic calculation on their raw data like you are suggesting. This is called "peer review", and very common in scientific journals... even if it is more informal than an organized panel. That is in fact why results like this are published in journals like this, so these kind of mistakes can be vetted.

          Or more to the point, if you want to make a name for yourself, look through the raw data, perform the calculations yourself, and show what mistake somebody with a PhD did with this sort of data. Many graduate students have indeed gained notice when they have performed exactly these sort of calculations.

          Have fun! Seriously, I mean it!
      • Re: (Score:3, Informative)

        by DerekLyons ( 302214 )
        If such a source did exist, and was in fact the cause of the Pioneer anomaly - it wouldn't be be the Pioneer anomaly as we'd have seen it's effects on the outer planets decades ago. This goes 1x10^10 for NEAR which has barely left the inner solar system.
        • Re: (Score:3, Interesting)

          we'd have seen it's effects on the outer planets decades ago

          Perhaps not. According to the summary and the article, the effect dies down the closer you get to the ecliptic plane (i.e. where the planets are).

          One could imagine that the local dark matter field (or whatever) has been swept up, in the ecliptic, by the sun and the planets.</handwave>
    • Re:Hmmm..... (Score:5, Informative)

      by florescent_beige ( 608235 ) on Friday February 29, 2008 @12:32PM (#22601076) Journal

      According to this [aip.org], the acceleration anomaly can't be accounted for by dark matter.

    • Here is an interesting explanation for it by a PhD. with the following credentials:

      Beginning in 1979 he worked for Sandia National Laboratories (New Mexico) in nuclear physics, geophysics, pulsed-power research, and theoretical atomic and nuclear physics. In 1985, he began working with Sandia's 'Particle Beam Fusion Project', and was co-inventor of special laser-triggered 'Rimfire' high-voltage switches, now coming into wider use.

      The last few years at Sandia had seen greater emphasis on theoretical nu

      • I think it is more of the human ability to interpret vagueness into anything. The genesis description of the origin of the universe lends itself to analogy, which he uses in that paper. Now his physics may be accurate in that the Universe may extend much further than the matter we can detect, and that may explain the velocity anomaly. But to extend that to say that a very vague story from 3000 years ago is a true an accurate description of the universe's origins and that therefore the bible is literally true is just fantasy.

        I've never been a believer. Recently, after reading The Selfish Gene and seeing just how much real evidence there is for evolution and seeing that science really _is_ an accurate and true explanation for how we came to be on the earth. It really does explain away any "need" for any sort of "personal god" as an alternate explanation. So, to give equal time to "the other side", I tried to read the bible. I got thru Genesis, but realized that there really is "nothing there" as far as explanatory power. And certainly to try to extract morals from the old testament would be a mistake. So then I got "Skeptics Answered" and again, there really isn't anything to the arguments of the believers.

        While I'm interested in why people believe, and how we can change that going forward, I've really lost interest in _what_ they believe. It really holds no value as near as I can tell.
    • Could both this *and* dark [x] be explained by gravitons reaching our brane from other branes in the bulk?
    • by Kagura ( 843695 ) on Friday February 29, 2008 @12:57PM (#22601512)
      Sadly, none of us can probably make a useful suggestion on this topic (one that would have eluded all the physicists that have been working on this). Unless the next Einstein is reading Slashdot,we can only make narrow conjectures. How many of us have the knowledge and data required? We might as well try to diagnose a medical condition based on a cursory discussion. It's fun to talk about, though.
    • Did you mean Dark Energy? That's the one that's the unexplained expansion acceleration in spacetime that we don't understand yet.
    • Re:Hmmm..... (Score:5, Informative)

      by CheshireCatCO ( 185193 ) on Friday February 29, 2008 @01:56PM (#22602434) Homepage
      I can't speak to this specific case, but someone did a study several years ago of the Voyager anomaly and whether it could be a gravitational effect. The gist of the analysis was the if it were gravitational, it would also affect the distribution of long-period comets, especially the "new" ones from the Oort cloud. They calculated the effect you'd expect and it's much too large relative to what we see in the comets, so whatever is affecting Voyager pretty much cannot be gravitational in nature.

      It's also worth noting that even in the mega-analysis by Anderson et al. concluded that although they couldn't determine a source for the anomaly, they still generally felt that it was more likely to be endogenic than exogenic.
  • This is ALIENS messing with us as a cosmic joke....
  • Not to be a grammar nazi and all... but "unsymmetrical"..? Really? I thought it was asymmetrical. But maybe I'm just weird and confused and grumpy.

    M.

    • Though it probably depends on your definition of the term grammar.
    • by sm62704 ( 957197 )
      Ewe muss bee knew hear! If you cross unsymmetrical with asymmetrical do you get analsymetrical?

      At least he didn't mention two "looser asymmetrical's". Then he'd have had me Godwining on his ass.
    • Re:I mean... (Score:4, Informative)

      by reverseengineer ( 580922 ) on Friday February 29, 2008 @12:45PM (#22601312)
      Both "asymmetric" and "unsymmetric" are in accepted use, though "a" is a lot more common than "un," particularly in math and physics (so yes, "asymmetric" would probably be more common to describe a spacecraft trajectory).

      Chemists use "un" to describe non-symmetric molecules pretty often- consider the rocket fuel UDMH: unsymmetrical dimethylhydrazine, though chemical reactions lacking symmetry are more often called "asymmetric," like the Sharpless asymmetric epoxidation. Asymmetric reactions can sometimes produce unsymmetrical products. Yes, it is unpossibly confusing. Just make sure to not confuse either "asymmetric" or "unsymmetric" with "antisymmetric."

  • Good excuse (Score:5, Funny)

    by Anne_Nonymous ( 313852 ) on Friday February 29, 2008 @12:10PM (#22600740) Homepage Journal
    I'm sorry officer; I was experiencing a velocity anomaly.
  • An appropos quote (Score:5, Insightful)

    by jandrese ( 485 ) <kensama@vt.edu> on Friday February 29, 2008 @12:11PM (#22600756) Homepage Journal
    Someone once said: The most profound scientific discoveries never begin with EUREKA! Usually they start with the words "now that's odd..."
    • by AndroidCat ( 229562 ) on Friday February 29, 2008 @12:17PM (#22600838) Homepage
      I thought it was "Here, hold my beer."
    • Re:An appropos quote (Score:5, Informative)

      by tppublic ( 899574 ) on Friday February 29, 2008 @12:23PM (#22600916)
      I believe you're referring to: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but rather, 'That's funny...'"-Isaac Asimov

      Occasionally this is also quoted as ending with 'Hmm, that's funny'.

      • Re: (Score:3, Funny)

        by jandrese ( 485 )
        That's probably right. I only vaguely remembered the quote and did a Google search for it, but only turned up the version I posted.
      • Re: (Score:3, Insightful)

        by Cerebus ( 10185 )
        Miller's Corollary to Asimov's Law: "Great discoveries in computer security are usually preceded by 'This can't possibly work.'"
    • Re: (Score:2, Interesting)

      by Eukariote ( 881204 )

      I wish, though, that that were more true than it actually is in science. Quite a few anomalies are being ignored because resolving them would challenge "sacred" theories.

      Anyone familiar with modern physics should be appalled by its complexity, confused by the many correction and perturbation factors, and amazed at the many weird theories propounded in all sincerity to explain observations in terms of "established theories". Anomalies are the rule rather than the exception, and the amount of data which jus

    • Someone once said: The most profound scientific discoveries never begin with EUREKA! Usually they start with the words "now that's odd..."

      Why would Sci-Fi Channel name a series "Now That's Odd"?
  • well duh (Score:5, Funny)

    by circletimessquare ( 444983 ) <circletimessquar ... l.com minus poet> on Friday February 29, 2008 @12:15PM (#22600804) Homepage Journal
    gravitons display a bias for polar rather than equatorial output. this was the basis for the graviton engine that first bought man...

    oh shit, forgot what time line was in, you guys aren't supposed to discover this until 2039. dang it, screwed up again. i'll have to shut this time line down...
    • John, yet ANOTHER Slashdot ID??? We told you to stop trolling here!
  • by rbarreira ( 836272 ) on Friday February 29, 2008 @12:17PM (#22600822) Homepage
    We're sorry about the bugs you've been observing lately. The latest anomalies are due to bug #14310, a hardware glitch much like those present in your own Pentium processors.

    We're trying as hard as we can to mitigate this issue, primarily by avoiding the use of floating point calculations in our physics engine. In the meantime, we're manually changing your physics books so that you'll be able to calculate the ship's movement correctly. In one day, you'll have no memory that this incident ever happened, so do not worry.
  • And... (Score:4, Informative)

    by djupedal ( 584558 ) on Friday February 29, 2008 @12:28PM (#22600996)
    Number 857 #2, February 28, 2008 by Phil Schewe

    More Spacecraft Velocity Anomalies

            A new look at the trajectories for various spacecraft as they fly past the Earth finds in each case a tiny amount of surplus velocity. For craft that pursue a path mostly symmetrical with respect to the equator, the effect is minimal. For craft that pursue a more unsymmetrical path, the effect is larger. In the case of the NEAR asteroid rendevous craft (), for instance, the velocity anomaly amounts to 13 mm/sec. Although this is only one-millionth of the total velocity, the precision of the velocity measurements, carried out by looking at the Doppler shift in radio waves bounced off the craft, is 0.1 mm/sec, and this suggests that the anomaly represents a real effect, one needing an explanation.

            Some ten years ago another anomaly was identified for the Pioneer 10 spacecraft (see http://www.aip.org/pnu/1998/split/pnu391-1.htm [aip.org]) and a certain amount of controversy has clung to the subject since then. One of the researchers on that earlier measurement is part of the new study, conducted by Jet Propulsion Lab scientists. John D. Anderson (jdandy@earthlink.net, 626-449-0102) says that the JPL scientists are now working with German colleagues to search for possible velocity anomalies in the recent flyby of the Rosetta spacecraft. (Anderson et al., Physical Review Letters, upcoming article; designated as an editor's suggested articlePhysical Review Letters)

  • We might find an explanation for this anomaly, or it could not be an anomaly. Laws of nature might be changing from time to time, and even if we have looked into the past till the first seconds before the big bang and even if we were correct in our interpretation there is no guarantee that laws can't change starting here and now. Limit reached when guys study the system they're part of.
  • by kiick ( 102190 ) on Friday February 29, 2008 @12:30PM (#22601034)
    Once you leave Earth for a while, particularly if you travel far, you realize that it doesn't suck quite as much as you thought.

    A similar phenomenon occurs when traveling outside of the U.S.
  • by Anonymous Coward
    Nasa & JPL determined in late October that the extra push pressure is from slight low energy gamma radiation from the core of our galaxy being red-shifted by going "uphill" (yeah, I know bad rubber-sheet analogy) out of the gravity well of the entire milky way. The spiral rotation factor of the spiral (once every 55 million years), though slight, is conjectured to impart further pressure of about 2.8 mm/sec.

    It isn't noticable closer in because the heliopause outweights everything else. Only when you g
  • Apparently god only had "inches" rulers handy when creating the universe, wouldn't ya know it!
  • They're using the doppler effect to measure. Maybe they should try some other measurement techniques as well to see if they all match up. It might be a measurement error of some sort.

  • by rangek ( 16645 ) on Friday February 29, 2008 @12:44PM (#22601298)

    The precision of the measurements is 0.1 mm/sec, not the accuracy. Those are different things.

  • The statement that the effect is less for symmetrical about the equator flybys and greater for asymmetrical ones suggests some systematic error in the measurements.

    They are talking an descrepency of 1 part on 10^6. As they say its absolute value is 1.3x10^-2 that means the relative velocity is 1.3x10^4. So boost (which is down around 10^-10) is not a factor.

  • Could it have anything to do with frame dragging? That would explain differences based on symmetry to the equator.
  • ... welcome our massive stealth alien observation ship owners overlords
  • by glenmark ( 446320 ) on Friday February 29, 2008 @01:24PM (#22601916) Homepage
    The solar wind output from the sun is anisotropic, and can certainly account for variations in a space probe's velocity. I'm wondering if that was taken into account in their calculations.
  • Simpler explanation? (Score:3, Informative)

    by ChrisMaple ( 607946 ) on Friday February 29, 2008 @01:24PM (#22601918)
    The article has little information about what types of trajectories are affected, so this is just wild guessing. If the orientation of solar panels or dish antennas are markedly different for different trajectories, drag from particles or acceleration from absorbing/reflecting solar radiation can also differ. There's more garbage in the plantary plane, so there's more drag and more blocking of solar radiation.
  • Am I the only one who gets this fuzzy warm feeling that it looks like an effect of a SF MacGuffin explaining why, finally, it is possible to travel between stars in less than a year ?
  • by harvey the nerd ( 582806 ) on Friday February 29, 2008 @01:32PM (#22602066)
    The Pioneer 10 and 11 speed-position anomalies, unaccounted drift, were noticed by the late 70's. NASA and the peole involved just didn't discuss it with the public until much later, after many potential sources of error and theoretical possiblities had been analyzed. That is when I first heard it mentioned, in Houston, ca 1977-78.
  • by uss ( 1151577 ) on Friday February 29, 2008 @01:34PM (#22602092)
    We've seen this Metric-hogwash replay innumerable times, when dealing with stuff flying around in the heavens.

    If those europeans and europeans-wanna-be stopped using fancy units of measurements, and just plainly used the well-worn all-American "Inches/just-a-sec" for measurements, there would be no anomolies.

    The only mm/sec I know, is the # of m&ms I can pop into my mouth per second.

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