PDA

View Full Version : Pioneer 10's Anomaly



John Kierein
2003-Jun-01, 11:44 PM
http://www.newtonphysics.on.ca/Anomalous/Acceleration.html
This says it's due to dust in the Kuiper belt. Whaddaya think of that?

wedgebert
2003-Jun-01, 11:48 PM
I say the next probe should bring some Pledge and a dusting rag along to clean up the belt.

Kizarvexis
2003-Jun-03, 12:54 AM
I found this near the end interesting.


Finally, considering that the Pioneer spacecrafts are submitted to such an acceleration of about 8. x 10-8 cm/s2 while moving through an enormous Kuiper and Oort cloud, the spacecrafts will absorb that dust due to the mechanism of accretion of dust. After millions of years of accretion, these spacecrafts will become larger and larger in time, while slowing down (unless reaccelerated later by other bodies). Pioneer spacecrafts will become the nucleus of asteroids flying away from the solar system with the interstellar dust.

So if in a million years Pioneer 11 passes near an alien civilization, they may not know it is artificial and think it is just another pile of rock and dust? So much for worrying about whether some alien will understand the plaque or not. :)

Kizarvexis

tracer
2003-Jun-03, 12:58 AM
Uh oh -- how many small comets and asteroids in our solar system are really dust-caked space probes sent out from other star systems? :o

Grand Vizier
2003-Jun-03, 01:04 AM
I found this near the end interesting.


Finally, considering that the Pioneer spacecrafts are submitted to such an acceleration of about 8. x 10-8 cm/s2 while moving through an enormous Kuiper and Oort cloud, the spacecrafts will absorb that dust due to the mechanism of accretion of dust. After millions of years of accretion, these spacecrafts will become larger and larger in time, while slowing down (unless reaccelerated later by other bodies). Pioneer spacecrafts will become the nucleus of asteroids flying away from the solar system with the interstellar dust.

So if in a million years Pioneer 11 passes near an alien civilization, they may not know it is artificial and think it is just another pile of rock and dust? So much for worrying about whether some alien will understand the plaque or not. :)

Kizarvexis

Yeah :) It seems that the authors haven't spotted their own little logic problem. If this dust is so adhesive, why is it still there? - we consider that there are possibly billions of bodies in the Kuiper belt, most of them much much larger than the Pioneers. They should all be sweeping up and accreting this magic dust, so there would be precious little left over by now for the probes to undergo this snowball process and turn themselves into interstellar asteroids.

AK
2003-Jun-03, 02:53 AM
How was this acceleration detected? I thought Pioneer 10 was no longer functional...

Tuckerfan
2003-Jun-03, 06:41 AM
I found this near the end interesting.


Finally, considering that the Pioneer spacecrafts are submitted to such an acceleration of about ?8. x 10-8 cm/s2 while moving through an enormous Kuiper and Oort cloud, the spacecrafts will absorb that dust due to the mechanism of accretion of dust. After millions of years of accretion, these spacecrafts will become larger and larger in time, while slowing down (unless reaccelerated later by other bodies). Pioneer spacecrafts will become the nucleus of asteroids flying away from the solar system with the interstellar dust.

So if in a million years Pioneer 11 passes near an alien civilization, they may not know it is artificial and think it is just another pile of rock and dust? So much for worrying about whether some alien will understand the plaque or not. :)

KizarvexisHeh. Can you imagine if that's what killed off the dinosaurs?:o A giant asteroid that started life off as an alien probe, and then fell to Earth killing the dinos off. Bummer that.

kilopi
2003-Jun-03, 06:52 AM
http://www.newtonphysics.on.ca/Anomalous/Acceleration.html
This says it's due to dust in the Kuiper belt. Whaddaya think of that?
Nice nod down there at the bottom, John: "The author acknowledges the collaboration of John Kierein for bringing up the IRAS information"

But, I am concerned about the titles on the FAQ page (http://www.newtonphysics.on.ca/faq/faq.html). "Series #8 Why Quantum Mechanics is Non-sense? " for instance, or "Series #14 They burn heretics, don't they?".

I looked into the Series #10: Energy Required to Move a Mass from the Pole to the Equator. (http://www.newtonphysics.on.ca/faq/relativity-GPS-10.html) Although I didn't wade through the math, it looks like the conclusions were OK. I was concerned because of the blurb on the main page: " It requires external (Earth) energy to move from the equator to the pole..." That is wrong, as Paul's writeup goes to great lengths to show. The surface at the pole and the surface at the equator are in an equilibrium, as the main body of the article states. The entire surface (geoid, or "sealevel") of the Earth is an equipotential surface, in other words.

That's why the water is "flat". :)

It also neatly explains the relativity phenomenon.

John Kierein
2003-Jun-03, 12:48 PM
I pointed out the IRAS picture to Paul. It's interesting that the Pioneer drag data may be the only direct measurement of the dust density. I was a little surprised that it hadn't been considered before.

The IRAS picture has always been interesting to me because it dramatically shows that the projection of the plane of the ecliptic crosses the galactic plane right at the center of the galaxy. I've always wondered if there's a gravitational reason for this and if it is true for other planetary systems. Unfortunately, so far as I have been able to find out, there is not yet a way to determine the orbital planes of extrasolar planets.

We also studied the zodiacal light and gegenschein from Skylab. I collected the pictures for this chapter:
http://history.nasa.gov/SP-404/ch3.htm

nebularain
2003-Jun-03, 02:19 PM
I found this near the end interesting.


Finally, considering that the Pioneer spacecrafts are submitted to such an acceleration of about –8. x 10-8 cm/s2 while moving through an enormous Kuiper and Oort cloud, the spacecrafts will absorb that dust due to the mechanism of accretion of dust. After millions of years of accretion, these spacecrafts will become larger and larger in time, while slowing down (unless reaccelerated later by other bodies). Pioneer spacecrafts will become the nucleus of asteroids flying away from the solar system with the interstellar dust.

So if in a million years Pioneer 11 passes near an alien civilization, they may not know it is artificial and think it is just another pile of rock and dust? So much for worrying about whether some alien will understand the plaque or not. :)

Kizarvexis

So does that mean instead of V-ger we will be revisited by P-neer? :o :P

rsa
2003-Jun-03, 03:31 PM
I'm not impressed. As far as I can tell, once you remove the "filler", they just assume a density and size of "sand" grains which then magically accounts for the acceleration and then they claim their assumptions as the result!

The "study" makes no reference to changes in acceleration over different time frames. If this idea was correct, there should be no anomalous acceleration except while traversing the Kuniper belt. This is not what has been observed.

The level of analysis here is pretty laughable when compared to the 2002 study (54 pages worth) by Anderson, et. al. And note that the authors still think there is a systematic reason for the acceleration, so they are not arguing for "farfetched hypotheses". http://xxx.lanl.gov/abs/gr-qc/0104064

informant
2003-Jun-03, 04:00 PM
Here (http://www.badastronomy.com/phpBB/viewtopic.php?p=92437#92437)'s another interesting article about the anomalous deceleration of the Pioneers.

Spaceman Spiff
2005-Mar-17, 09:37 PM
http://www.newtonphysics.on.ca/Anomalous/Acceleration.html
This says it's due to dust in the Kuiper belt. Whaddaya think of that?

This article (http://arxiv.org/abs/astro-ph/0503368) submitted to a journal for review finds the following:


In this work we study the gravitational influence of the material extending from Uranus orbit to the Kuiper belt and beyond on objects moving within these regions. We conclude that a density distribution given by rho(r) ~ 1/20r (for r > 20 AU) generates a constant acceleration towards the Sun on those objects, which accounts for the blue shift detected on the Pioneers space crafts. We also discuss the effect of this gravitational pull on Neptune, and comment on the possible origin of such
a matter distribution.

ToSeek
2005-May-10, 05:08 PM
Use asteroids to investigate (http://www.newscientist.com/article.ns?id=mg18624984.700)


FAR-FLUNG asteroids could help reveal the nature of the mysterious force that has nudged NASA's 33-year-old Pioneer 10 spacecraft about 400,000 kilometres off course.
...
Gary Page of George Mason University in Fairfax, Virginia, and his colleagues have identified 15 asteroids that might also be subjected to the mysterious force. The asteroids' orbits all stretch far into the outer solar system. This is crucial because the Pioneer anomaly only shows up beyond about twice the distance from the sun to Saturn.

Nick
2005-May-10, 08:22 PM
So if in a million years Pioneer 11 passes near an alien civilization, they may not know it is artificial and think it is just another pile of rock and dust? So much for worrying about whether some alien will understand the plaque or not. :)

Kizarvexis

Nope. They will launch a HUGE copper ingot 'bullet' to smash it to bits to see what it is made of.

Nick :wink:

umop ap!sdn
2005-May-10, 09:22 PM
...the projection of the plane of the ecliptic crosses the galactic plane right at the center of the galaxy. <snip> Unfortunately, so far as I have been able to find out, there is not yet a way to determine the orbital planes of extrasolar planets.
But we do have orbit planes for some binary stars (the Hipparcos catalogues have a doubles and multiples annex with orbital information); I just checked a bunch of them at random and a disproportionate number seem to intersect the plane of the galaxy within 20-30 of the galactic center - Sirius B in particular is almost right-on despite its orbit being tilted on its side with respect to the plane of the galaxy.

Not to hijack the thread or anything :oops: but I'd say you may be on to something.

umop ap!sdn
2005-Jun-04, 12:57 AM
Not to hijack the thread or anything

I've always wondered if there's a gravitational reason for this and if it is true for other planetary systems.
(I wasn't paying attention and didn't notice at first that you were the OP. #-o )

But having completed a survey of binary stars with known orbit planes, I did find something interesting. I measured the apparent declination of the galactic center (GC) as seen from each star, referenced to the plane of its companion's orbit. I also took into account the obliquity of the orbit to the galactic plane.

If my math is correct (and please do correct me if I've made any errors) then in a perfectly random distribution one would expect a mean obliquity of 90 / sqrt(2), and a mean declination equal to the mean obliquity / sqrt(2).

In fact, I found a mean obliquity of 57.46 which is a little over 90% of the expected figure. So there's a slight tendency for stellar orbits to want to lay flat against the galactic plane. The mean declination of the GC is only 71% of the expected figure, meaning the orbits have a considerably greater tendency to line up to the GC as you describe. Furthermore, when each individual star system's apparent GC declination is divided by its obliquity, the resulting mean is higher - closer to 74%.

The difference between the 71% and 74% figures can be explained if stars whose orbit planes lie closer to the plane of the galaxy have less tendency to line up with the GC than stars whose planes have a high obliquity.

Here (http://www.eknent.com/etc/gcdecl_nomacr.xls) is a complete MS Excel spreadsheet of the stars I surveyed and resulting figures.

umop ap!sdn
2005-Jun-08, 09:49 AM
Bump.

Questions? Comments? Point out some major error on my part? :lol: Anyone?

That survey took me almost 3 weeks. :wink: (Satisfied my own curiosity, at the very least, so it was worth it.)

ToSeek
2005-Nov-10, 07:29 PM
Planetary Society coverage of the
2005 Pioneer Anomaly Conference
November 6-11, 2005 (http://planetary.org/programs/projects/pioneer_anomaly/update_200511.html)


Greetings from Switzerland! My name is Merek Chertkow. The Planetary Society sent me to the 2005 Pioneer Anomaly Conference in Bern, Switzerland to participate in and report on the exciting analyses, conclusions, and new questions formed by scientists from around the world working to understand the Pioneer anomaly. The conference consists of some 15 scientists from France, Canada, Norway, Germany, and the United States.

Throughout the week, I'll try to introduce and remind you of the different complicated elements involved in understanding the Pioneers' position, environment, the way in which it communicates with Earth, and the current modeling techniques that are being used.

publiusr
2005-Nov-10, 08:23 PM
Planetary Society coverage of the
2005 Pioneer Anomaly Conference
November 6-11, 2005 (http://planetary.org/programs/projects/pioneer_anomaly/update_200511.html)

That is a good link.
Not only can a space probe be covered with debris, but the metal itself forms these small fiber like burr/extrusions to bond with it.

It makes me wonder about Teton again.

Jerry
2005-Nov-10, 11:15 PM
Bump.

Questions? Comments? Point out some major error on my part? :lol: Anyone?

That survey took me almost 3 weeks. :wink: (Satisfied my own curiosity, at the very least, so it was worth it.)

Applause!

There are a number of reasons to suspect an underlying symmetry that is not predicted by Newton - Bode's law, the correlation between planetary energy emission excess and rotational speed, the roundness of planetary orbits (assuming they are captured, rather than cloud synthesized). Many of these phenomena are written off as coincidental, but I don't see how the relationship you just describe could be. (I have an explanation, but now is not the time or the place, and it is probably wrong anyway.)

I'll file this somewhere between the Tiger Stripes of Enceladus, and the fact that the rotational period of Venus correlates quite well with the Earth/Venus orbital periodic. (The same face of Venus always points towards the Earth.)

ToSeek
2006-Feb-01, 08:09 PM
Update from the Pioneer Anomaly Team (http://planetary.org/programs/projects/pioneer_anomaly/update_200601.html)


The original investigation used about 11.5 years worth of data for Pioneer 10, and slightly less than 4 years of data for Pioneer 11. We can now report on the recovery of a much larger data set: essentially all Doppler data for the entire 30-year time span of the Pioneer 10/11 missions will soon be available for analysis. This is not an easy process: 30 years is a very long time! The challenges are formidable, including having to deal with numerous obsolete data formats, no longer supported software packages, and last but not least, the fact that people with the right expertise are no longer around. Nevertheless, the formats are now understood and the media has been collected. We now have up to 60,000 data points (about 20 gigabytes) of data for Pioneer 10, and 50,000 data points (about 15 gigabytes) for Pioneer 11. The data recovery process in nearly complete and the data will be available for the analysis in early this year.

Doodler
2006-Feb-01, 08:28 PM
I don't buy it. How can a pair of spin stabilized probes be suffering this dust phenomenon, but not two probes that are relatively stable platforms? Yes, they are thruster stabilized, but it should have shown up somewhere that additional thrust was required to accomplish adjustments, or that adjustments weren't having the desired effect.

Something stinks here.

ToSeek
2006-Feb-01, 09:16 PM
I vote for some sort of systemic effect based on unaccounted-for aspects of the spacecraft. As Ned Wright points out, the effect is so small that it's equivalent to shining a 60-watt light on (or from) the spacecraft. I find it easier to believe that something like that was missed than that we're talking about new physics.

The_Radiation_Specialist
2006-Feb-02, 09:36 AM
Pioneer 10 is just getting too tired. wouldnt you want to slow down a bit after a 15 billion km journey? ;)

gwiz
2006-Feb-02, 09:47 AM
I don't buy it. How can a pair of spin stabilized probes be suffering this dust phenomenon, but not two probes that are relatively stable platforms? Yes, they are thruster stabilized, but it should have shown up somewhere that additional thrust was required to accomplish adjustments, or that adjustments weren't having the desired effect.

Something stinks here.
The trouble with the Voyagers is that every attitude stabilisation manoeuvre also alters the velocity slightly because the thrusters are not exactly balanced. This effect, though small, is sufficient to completely swamp the Pioneer effect.

Doodler
2006-Feb-02, 02:07 PM
The trouble with the Voyagers is that every attitude stabilisation manoeuvre also alters the velocity slightly because the thrusters are not exactly balanced. This effect, though small, is sufficient to completely swamp the Pioneer effect.

Still, if something were accumulating on the probes, there would be some level of alteration to the probe's performance. It would be a different anomoly, but there would still be an anomoly of some kind.

Nonkers
2006-Apr-28, 09:10 AM
What are the implications of the acceleration anomalies measured for Pioneer 10 and 11 http://www.setterfield.org/accelanom.htm ?


Although Setterfield's a creationist, variable c" models aren't that rare -- Hoyle and Narlikar proposed one where the value of c was a function of the local energy density, for example. Who knows what constitutes conclusive proof, since other constants of nature shift with c (e.g., the electrical permittivity and magnetic permeability of free space, not to mention other constants)?

antoniseb
2006-Apr-28, 12:57 PM
What are the implications of the acceleration anomalies measured for Pioneer 10 and 11 http://www.setterfield.org/accelanom.htm ?


Many alternative theorists point to the Pioneer 10 and 11 anomalies, which show a slight increase in the force experienced toward the Sun as the spacecraft get further out into the Solar System. If you call everything in Physics into question, then any small number of things we hold as known physics might be wrong, which would require that radical explanations of the rest of the universe would be in order. This section of the forum isn't really the place to explore a catelog of these implications. Try the ATM section.

Jerry
2006-May-01, 03:16 AM
Many alternative theorists point to the Pioneer 10 and 11 anomalies, which show a slight increase in the force experienced toward the Sun as the spacecraft get further out into the Solar System. If you call everything in Physics into question, then any small number of things we hold as known physics might be wrong, which would require that radical explanations of the rest of the universe would be in order. This section of the forum isn't really the place to explore a catelog of these implications. Try the ATM section.
I think the Pioneer anomalies are an exception to the rule here: This is a well studied phenomenon where most of the suggestions as to cause on this thread have been ruled out by a team a very competent researchers. This is one of several observations that should be considered a gut-check for the mainstream, because it is mainstream: Two well-controlled experiments, the results of which have no known causality.

mugaliens
2006-May-02, 12:47 PM
The surface at the pole and the surface at the equator are in an equilibrium, as the main body of the article states. The entire surface (geoid, or "sealevel") of the Earth is an equipotential surface, in other words.

That's why the water is "flat". :)

It also neatly explains the relativity phenomenon.

Actually, while it's equipotential with respect to altitude, it's not equipotential with respect to total energy. Don't forget objects at the equator, include the surface of the ocean, is travelling about 1,000 mph faster, Eastward, than the poles. This is rocket launches take place in more Southern regions.

As for the rest of the article on Pioneer 10, couldn't tell you.

Are there radios of two frequencies, though? Different freqs are slowed down by interferring medium (gas/dust) at different rates. This is one means GPS uses to detect/adjust for ionosphere abberations. If P-10 had two radios, sending a ping on both and measuring the different times we received it might tell us not only redshift, but actual distance, as well as the density of the medium through which it's travelled.

But I'm sure the rocket scientists have thought of this!

turbo-1
2006-May-02, 08:12 PM
I think the Pioneer anomalies are an exception to the rule here: This is a well studied phenomenon where most of the suggestions as to cause on this thread have been ruled out by a team a very competent researchers. This is one of several observations that should be considered a gut-check for the mainstream, because it is mainstream: Two well-controlled experiments, the results of which have no known causality.In my opinion, the Pioneer anomaly is a demonstration of the Scharnhorst effect. Klaus Scharnhorst predicted that light propagating through a rarified quantum vacuum field (i.e. a vacuum in which a range of frequencies of virtual pairs is suppressed, as in a Casimir gap) should move faster than light that is propagating through an equivalent vacuum. Light can travel faster through propagating media that are less dense, and the shortened return times lead us to believe the probes are closer than they really are, and if we believe that the speed of light in a vacuum must be constant, we interpret this to mean that the probes are slowing. They are not.

I would like to explain further, but the explanation would be regarded as ATM. The summary of the vacuum polarization model is located here.

http://www.bautforum.com/showthread.php?t=35191

ToSeek
2006-Jun-06, 04:58 PM
30 Years of Pioneer Spacecraft Data Rescued:
The Planetary Society Enables Study of the Mysterious Pioneer Anomaly (http://planetary.org/about/press/releases/2006/0605_30_Years_of_Pioneer_Spacecraft_Data.html)


Before The Planetary Society stepped in to help, only about 11 years of Pioneer Doppler data had been analyzed, and the Pioneer anomaly remained a mystery. A lot of the remaining data (more than 19 years of it) were stored on old 7- and 9-track magnetic tapes needed to be saved and converted to modern media. By June 2006, scientists and engineers led by Slava Turyshev at the Jet Propulsion Laboratory were able to recover much of the more than 30-year navigational histories of both spacecraft.

I used to work with tapes just like the one depicted....

Nereid
2006-Jun-06, 05:36 PM
Moved to Astronomy section.

loglo
2006-Jun-06, 07:46 PM
I used to work with tapes just like the one depicted....

Used to be able to carry 22 on each arm in my days as a tape librarian. :D

ToSeek
2006-Jun-06, 08:44 PM
Used to be able to carry 22 on each arm in my days as a tape librarian. :D

Fortunately I never needed to carry 22 at a time. I remember having to make four tapes (four copies) to deliver some of my software, though.

Blob
2006-Aug-16, 08:39 PM
According to Michael Nieto of the Los Alamos National Laboratory in New Mexico, the data for Pioneer 10 was not precise enough around the time of its fly-by of Jupiter to indicate whether its acceleration problems began with that encounter. But, this may soon be remedied. JPL's Slava Turyshev recently unearthed archived data from Pioneer 10 and 11 and is reconstructing the missions in their entirety, which could help determine whether Pioneer 10's anomaly began with a fly-by too.

"That's what I want to look at more precisely" - Michael Nieto .

The researchers say that while it is possible that an overlooked effect from ordinary physics might account for the anomalies, something more exotic could also be involved. For example, the spacecraft trajectories could be influenced by the presence of dark matter in the solar system. Or maybe the laws of gravity need reworking.
Peter Antreasian, a spacecraft navigation expert at JPL who along with Joseph Guinn first brought attention to the anomalies seen in Galileo and NEAR during their Earth fly-bys, believes that it will require a modified law of gravity or other new physics to explain it. He does not think it is connected to the Pioneer anomaly, since the force behind this seems always to point in the same direction, back towards the sun. In the Earth fly-bys, by contrast, "a directional force such as the Pioneer anomalous force would have been very evident in the radiometric data in the last few days before the approach". Whatever causes this anomaly seems to make its impact just a few minutes before the closest approach to Earth.
Not everyone is convinced the Earth fly-by anomaly points to new physics. Myles Standish, who calculates trajectories of solar system bodies for JPL, says he feels the Earth fly-by anomaly is almost certainly due to an error in measurement or an incomplete analysis using ordinary physics.

http://www.newscientist.com

Jens
2006-Aug-17, 08:15 AM
He does not think it is connected to the Pioneer anomaly, since the force behind this seems always to point in the same direction, back towards the sun.

I'm intrigued by this statement, because it's something I've wondered about. Has the Pioneer anomaly been convincingly shown to be toward the sun? Because I understood there were three possibilities: (1) that it was toward the earth, indicating some measurement anomaly; (2) that it was toward the sun, indicating a gravitational anomaly; or (3) that it was in the trajectories, indicating something like dark matter slowing them down.

I think that if it is accepted that the acceleration is toward the sun, then gravity is the place to look for an explanation.

Blob
2006-Aug-18, 01:30 PM
Hum,
this is what the `new` data hopes to solve.

Flybys may be key to Pioneer anomaly (http://www.newscientistspace.com/article/mg19125654.100-flybys-may-be-key-to-pioneer-anomaly.html) (Subscription)

John Kierein
2006-Aug-18, 03:34 PM
I wonder what the temperature of the outer surfaces of the spacecraft are at this great distance from the sun. Perhaps they are so cold that ambient water and other molecules are condensing on them to make them get heavier from ices? Like comets forming. This in itself shouln't change the acceleration (all weights fall at the same rate), but maybe the condensation causes a drag?

John Kierein
2006-Aug-18, 03:44 PM
But we do have orbit planes for some binary stars (the Hipparcos catalogues have a doubles and multiples annex with orbital information); I just checked a bunch of them at random and a disproportionate number seem to intersect the plane of the galaxy within 20-30° of the galactic center - Sirius B in particular is almost right-on despite its orbit being tilted on its side with respect to the plane of the galaxy.

Not to hijack the thread or anything :oops: but I'd say you may be on to something.

I've been away from this thread for quite a while. I think you should write a paper on this and include the IRAS figure with it. Cool info!!! Print it upside down since this wouldn't affect the conclusions.

ToSeek
2007-Mar-02, 09:19 PM
Computer sleuths try to crack Pioneer anomaly (http://space.newscientist.com/article.ns?id=dn11304&feedId=online-news_rss20)


Scientists and engineers remain on course in their efforts to determine what caused the twin Pioneer spacecraft to apparently drift off course (http://space.newscientist.com/article/mg19125654.100) by hundreds of thousands of kilometres during their three-decade missions. Within a year, they expect to be able to decide whether this drift was caused by a fault on the spacecraft.

Jerry
2007-Mar-07, 05:29 AM
I'm intrigued by this statement, because it's something I've wondered about. Has the Pioneer anomaly been convincingly shown to be toward the sun? Because I understood there were three possibilities: (1) that it was toward the earth, indicating some measurement anomaly; (2) that it was toward the sun, indicating a gravitational anomaly; or (3) that it was in the trajectories, indicating something like dark matter slowing them down.

I think that if it is accepted that the acceleration is toward the sun, then gravity is the place to look for an explanation.
Neito & Co are not convinced the 'force' is strickly toward the sun. One of the reasons they wanted the earlier Pioneer data preserved, was to determine if there is an unexpected vector. Thanks to the Planetary Society, this data is being analysed, and we should get a better answer.

Maksutov
2007-Mar-07, 06:28 AM
One wonders if it had a close encounter with a small Kuiper Belt object. Not a hit, but close enough to affect it gravitationally and thus alter its acceleration and trajectory.


[edit]Myles Standish, who calculates trajectories of solar system bodies for JPL, says he feels the Earth fly-by anomaly is almost certainly due to an error in measurement or an incomplete analysis using ordinary physics.

http://www.newscientist.comIs he the spokesman for Professor Alden?

ozprof
2007-Mar-07, 02:44 PM
One thing I am curious about. Everyone talks about it as the Pioneer Anomaly, but what about the Voyagers? Has anyone every detected any similar anomaly with them?

aurora
2007-Mar-07, 03:41 PM
One thing I am curious about. Everyone talks about it as the Pioneer Anomaly, but what about the Voyagers? Has anyone every detected any similar anomaly with them?

I've been told that due to their nature the Voyagers cannot be used for this purpose. Something to do with the way the Voyagers keep themselves aligned.

Doodler
2007-Mar-07, 06:15 PM
I've been told that due to their nature the Voyagers cannot be used for this purpose. Something to do with the way the Voyagers keep themselves aligned.

Voyagers use reaction mass to stabilize, the Pioneers were spin stabilized.

ToSeek
2007-Mar-27, 08:12 PM
Newfound Data Could Solve NASA's Great Gravity Mystery (http://www.space.com/scienceastronomy/070327_scitues_pioneeranom.html)


But a wealth of newly recovered data and telemetry, spanning decades of observations by both Pioneer 10 and 11, may yield the final answer to whether conventional physics or perhaps something new is at work on the two spacecraft. An answer could arise from the new data after about a year of analysis by an international team of researchers.

“I would like to see this story reach its finality,” said Slava Turyshev, an astrophysicist with NASA’s Jet Propulsion Laboratory (JPL) who has spent the last 14 years—some of it on his own time—studying the Pioneer Anomaly. "So if it’s conventional physics, that’s fine and we can all go about our daily business. But if it’s something else, there may be another page.”

He and other fellow devotees discussed the astrophysics oddity late Monday during the Seventh Annual Asimov Debate here at the American Museum of Natural History.

ToSeek
2007-Mar-31, 02:36 AM
Pioneer Anomaly Project Update (http://planetary.org/programs/projects/pioneer_anomaly/update_20070328.html)


The availability of this new and much extended dataset is the most significant change since any other investigation performed to date. However, its analysis is technically complex, as we will have to "re-fly" the 30-year Pioneer missions. In other words, we will have to virtually "launch" the Pioneers, acquire their signals, perform the first orientation maneuver, and go arc-by-arc all the way to Jupiter and Saturn (for Pioneer 11), then fly by outer planets and leave the solar system while still transmitting scientific and engineering information -- and do that until the last data point. Our objective is to obtain the most precise trajectory solutions using the recently recovered data. However, the amount of work and its complexity are overwhelming; furthermore, this work must be done very carefully, with attention given to all pieces of information.

Sticks
2007-Oct-01, 05:19 AM
ICR have got in on this (http://icr.org/article/3472/)

What do you make of their dribblings?

Jerry
2007-Oct-04, 03:15 AM
Sigh. It is no wonder scientists are reluctant to publish anomalous results. If someone would have used Genisus to predict the scope and nature of the pioneer anomaly before Anderson published in 1998; that would have been impressive. (And saved Anderson & Co. a whole lot of work.)

Mary Baker Eddy is alive and well.

01101001
2007-Oct-04, 04:34 AM
Genisus

The Genesis (http://genesismission.jpl.nasa.gov/) mission?

Jerry
2007-Oct-05, 07:00 PM
Unless I got kidnapped by a router; Stick's reference used geometry based upon biblical creation to explain the pioneer results. (It should probably not have been posted here, but it hardly seems worthly of its own thread, even on atm.

Sticks
2007-Oct-05, 07:10 PM
Unless I got kidnapped by a router; Stick's reference used geometry based upon biblical creation to explain the pioneer results. (It should probably not have been posted here, but it hardly seems worthly of its own thread, even on atm.

I did wonder about ATM, but it is not my theory so I would not be in a position to defend it, according to ATM rules. As it was related to the Pioneer anomaly, I thought that this thread was the most suited. I assumed that if there were any gaping holes, you guys would be able to find them and rip it to shreds.

KaiYeves
2007-Oct-07, 02:45 AM
Perhaps it has to do with this (www.bautforum.com/small-media-large/60001-universe-history-channel.html#post1068737) "conspiracy". ;-D

Noclevername
2007-Oct-07, 07:25 PM
It's just dust off the Crystal Sphere that holds the stars in place. ;)

KaiYeves
2007-Oct-07, 07:58 PM
It's just dust off the Crystal Sphere that holds the stars in place
I don't know whether the idea of Pioneer 10 and Crystal Spheres sharing the same universe is very scary or very funny.

Jens
2007-Oct-09, 04:33 AM
Apparently the New Horizons probe is spin-stabilized. It's past Jupiter now, so I wonder how long it will be before there is a data that can be analyzed to see if the same thing is happening.

Jerry
2007-Oct-11, 04:09 AM
I have followed New Horizon's very closely, and to the best of my knowledge, a detailed gravity study is not in the making. We are still waiting for a precise comparison of NH's gravity assist from Jupiter. Since a coarse correction was not made until month's later, it can be assumed, 1) the assist was very close to what was predicted, 2) somebody knows how close.


Not everyone is convinced the Earth fly-by anomaly points to new physics. Myles Standish, who calculates trajectories of solar system bodies for JPL, says he feels the Earth fly-by anomaly is almost certainly due to an error in measurement or an incomplete analysis using ordinary physics.

Data, including error analysis, do not support this 'feeling', and too many scientists with their hands on the purse strings share it, leaving it up to the planetary society to pony up funding to pursue a solution. A follow Pioneer mission would have been worth a lot more scientifically than that silly gravity B probe.

William
2007-Oct-12, 03:32 AM
The reason there are scientific papers written concerning anomalies, is that science tries to explain the observation using current standard physics. When it appears to fail, the next step is to try new hypotheses.

I do not see how one can without detailed knowledge of the ultimate or true physics model, logically state a prior which anomalies will or will not advance physics.

The method Faraday used to handle uncertainty was to accept the anomaly as correct and then try to follow that line of logic to examine other sets of observations. Analogous to trying to fit pieces together of a complex puzzle where the true picture is not known.

Faraday solved problems that others could not because he tried different hypotheses and did not become emotionally attached to a specific hypothesis. After rejecting a hypothesis, he would often attempt to save the rejected hypothesis. He appeared to be completely neutral and fair.

In the case of the Pioneer anomaly, in my view, something basic appears to have been missed. What other force (i.e. Not a new force or new particle) could cause an attraction of the space probe to the sun?

In general, I personally support Nereid's and Cougar's discomfort in jumping to new physics (I do not support the dark matter or dark energy hypothesis).

KaiYeves
2007-Oct-13, 01:23 AM
Myles Standish
That was also the name of the leader of the Pilgrims. Wierd.
Well, it wasn't me.

Jerry
2007-Oct-16, 01:53 AM
The reason there are scientific papers written concerning anomalies, is that science tries to explain the observation using current standard physics. When it appears to fail, the next step is to try new hypotheses...

In general, I personally support Nereid's and Cougar's discomfort in jumping to new physics (I do not support the dark matter or dark energy hypothesis).
The Faraday story is interesting: New physics were a matter of coarse in his century. Today, new physics are only resorted to when they are necessary to salvage the existing model. I am talking specifically about the Dark Matter and Dark Energy hypotheses you eschew.

Whenever there is anomalous data such as the Pioneer experience, we should retest: Eliminate variables. Simply assuming there is something that the researchers are missing is unfair to them, and an offense to the spirit of discovery.

William
2007-Oct-16, 02:41 AM
In reply to Jerry's, "Whenever there is anomalous data such as the Pioneer experience, we should retest: Eliminate variables. Simply assuming there is something that the researchers are missing is unfair to them, and an offence to the spirit of discovery."

I do not disagree with your thought. First try to eliminate simple explanations. If the anomaly still remains, try different hypothesis, to try to resolve the anomaly.

Comment:
In this case, I believe the Pioneer anomaly is real. I think I can see a link between a group of anomalies. I have a rough hypothesis, with no new forces or particles, that seems to explain what is observed. I will see if I can tidy it up and see what you guys think. Probably take a couple of months.

It would be funny if the hypothesis is correct, as it seems a bit obvious, if the anomalies are viewed as a group rather than individually. Particularly if no new physics is allowed.

Jens
2007-Oct-16, 03:07 AM
In this case, I believe the Pioneer anomaly is real. I think I can see a link between a group of anomalies. I have a rough hypothesis, with no new forces or particles, that seems to explain what is observed. I will see if I can tidy it up and see what you guys think. Probably take a couple of months.


How about a sneak preview? You never know, somebody might have some further insights or show why it isn't possible.

Kaptain K
2007-Oct-16, 03:23 AM
...or show why it isn't possible.
Or is possible.

William
2008-Mar-01, 05:02 AM
Additional Spacecraft motion anomalies.

http://www.space.com/scienceastronomy/080229-spacecraft-anomaly.html


Mysteriously, five spacecraft that flew past the Earth have each displayed unexpected anomalies in their motions.


These newfound enigmas join the so-called "Pioneer anomaly" as hints that unexplained forces may appear to act on spacecraft.


A decade ago, after rigorous analysis, anomalies were seen with the identical Pioneer 10 and 11 spacecraft as they hurtled out of the solar system. Both seemed to experience a tiny but unexplained constant acceleration toward the sun.


Now Jet Propulsion Laboratory astronomer John Anderson and his colleagues who originally helped uncover the Pioneer anomaly have discovered that five spacecraft each raced either a tiny bit faster or slower than expected when they flew past the Earth en route to other parts of the solar system.

Jerry
2008-Mar-02, 12:32 AM
101101011 started a new thread on this article.

There are six sets of anomalous data relative to near-earth events that I am aware of 1) Gravitational assists, 2) Periodic displacements of the the GPS satellites during calibration 3) Displacement of Faulcutt pendelums during the delta g maxima, 4) Gravity 'B' probe calibration anomalies 5) Differential weights found in the continental mass standards when they are brought together. 6) Different values measured for 'g' in various locations.

It would be interesting to pull the net residuals for all of these unexpected observations together and look for threads of commonality.

antoniseb
2008-Mar-02, 01:36 AM
It would be interesting to pull the net residuals for all of these unexpected observations together and look for threads of commonality.

I have to agree with you there. I bet we'll see the results of such studies before the end of 2010. (I give such a long timeframe, because I think it will take a while to figure out how to work all the results together)

Nereid
2008-Mar-02, 01:18 PM
[snip]

3) Displacement of Faulcutt pendelums during the delta g maxima,

[snip]
What is a "Faulcutt pendelum", a "delta g maximum"?

I am unfamiliar with either term.

trinitree88
2008-Mar-02, 04:03 PM
What is a "Faulcutt pendelum", a "delta g maximum"?

I am unfamiliar with either term.

Nereid. I think that's Foucault pendulum...fixed plane of oscillation relative to the distant stars....Mach's principle. pete

Jerry
2008-Mar-02, 04:25 PM
Delta g maximum is when the rate of change in the net gravitational force vector is the greatest. It is an interesting phenomenon that has not always been repeatable, but it has shown up often enough in well-controlled situations that it shouldn't be written off as an artifact...yet.

Good but old overview:

http://science.nasa.gov/newhome/headlines/ast06aug99_1.htm

http://www.science-frontiers.com/sf074/sf074a05.htm

There was a lot of anticipatation prior to the 1999 solar eclipse, but very little follow-up on what was actually observed. I suspect the results were rather ambiguous:

http://pass.maths.org/issue9/xfile/


Tis year's eclipse in August, NASA and other groups attempted a range of experiments to finally confirm or deny the result. Their conclusions are still awaited, though at PASS Maths we have already heard that one laboratory in Austria replicated the effect.

http://home.t01.itscom.net/allais/blackprior/vienna/wuchterl.htm


...We propose a mechanism, based on pressure-modulated air drag, to account for the observed deviations. An eclipse-effect on a Foucault pendulum can then be explained as air drag modulation caused by the atmospheric pressure modulations due to the moon's shadow.

Obviously, more testing is needed.

KaiYeves
2008-Mar-02, 08:33 PM
Before you ask, I had nothing to do with this.

Nereid
2008-Mar-03, 12:27 AM
Nereid. I think that's Foucault pendulum...fixed plane of oscillation relative to the distant stars....Mach's principle. peteAh yes, I expect you are right, trintree88 ... it seems many of Jerry's posts contain errors in key terms (and worse), errors that may be sufficiently severe as to lead to serious misunderstanding ...

So, Jerry, did you intend "Foucault pendulum"?

Jerry
2008-Mar-03, 01:48 AM
I once typed 'James West Telescope' - and failed to correct it. Much of what I type comes out phonetic, and I have to go back and plink threw it again. I presented on the foulcutt pendulum effect, I wonder how i spelled it then. Sometimes, I have to admit, I will leave something wrong just to see who is still listening (Try posting an equation where the units don't add up, and Celestial Mechanic always pops out of the woodwork.)