The Pioneer Anomaly Options

[ljk4-1]

Quotes from the article "Listening for Pioneer 10":

Centauri Dreams is following the Pioneer 10 story with great interest, and not just in terms of the anomalous effects that continue to keep this mission in the news. Ponder that Pioneer 10 was launched in 1972 and consider that even with the technologies of its day, the probe may still be able to communicate with Earth.

We have learned so much in the interim about hardened electronics and autonomous self-repair that there is reason to believe probes to even remoter locations in the Kuiper Belt and beyond are feasible providing we can solve the propulsion conundrum.

...

It’s too late for New Horizons, of course, but any followup Pluto/Kuiper Belt mission would have such an opportunity. On that score, see T. Bondo, R. Walker, A. Rathke et al., “Preliminary Design of an Advanced Mission to Pluto,” scheduled to appear in the proceedings of the 24th International Symposium on Space Technology and Science, Miyazaki, Japan, June 2006, and already available online (PDF warning).

http://www.centauri-dreams.org/?p=534

[The Messenger]

General Relativity and Quantum Cosmology, abstract
gr-qc/0602003

From: Antonio F. Ranada [view email]

Date: Wed, 1 Feb 2006 15:30:16 GMT (10kb)

A model for the Pioneer Anomaly

Authors: Antonio F. Ranada, Alfredo Tiemblo

Comments: 11 pages, no figures

We propose an explanation to the Pioneer Anomaly, the anomalous blueshift in the radio signals from the Pioneer 10/11 spacecrafts that remains unexplained 30 years after being discovered by a NASA team around 1975. It was detected as a Doppler shift that does not correspond to any known motion of the ships. In 1998, after many unsuccessful efforts to account for it, the discoverers suggested "the possibility that the origin of the anomalous signal is new physics".

We show here that the phenomenon has the same observational footprint as an acceleration of the atomic clocks time with respect to the astronomical time...
http://arxiv.org/abs/gr-qc/0602003

...It also has the same observational footprint as an increase in the speed of light with increasing distance from the center of mass. A family of observations that don't fit the mold could be a clue that all is not well in the beeg peekture.

[ljk4-1]

Astrophysics, abstract
astro-ph/0602266

From: Joao Magueijo [view email]

Date: Sun, 12 Feb 2006 20:46:43 GMT (240kb)

MOND habitats within the solar system

Authors: Jacob Bekenstein, Joao Magueijo

MOdified Newtonian Dynamics (MOND) is an interesting alternative to dark matter in extragalactic systems. We here examine the possibility that mild or even strong MOND behavior may become evident well inside the solar system, in particular near saddle points of the total gravitational potential. Whereas in Newtonian theory tidal stresses are finite at saddle points, they are expected to diverge in MOND, and to remain distinctly large inside a sizeable oblate ellipsoid around the saddle point. We work out the MOND effects using the nonrelativistic limit of the T$e$V$e$S theory, both in the perturbative nearly Newtonian regime and in the deep MOND regime. While strong MOND behavior would be a spectacular ``backyard'' vindication of the theory, pinpointing the MOND-bubbles in the setting of the realistic solar system may be difficult.

Space missions, such as the LISA Pathfinder, equipped with sensitive accelerometers, may be able to explore the larger perturbative region.

http://arxiv.org/abs/astro-ph/0602266

[ljk4-1]

I don't want this turning into the Dark Matter/Energy Topic (unless of course that is what is affecting the Pioneer probes), but I wanted to share this news item while we are still on the subject:

Dark Matter Galaxy?

Summary - (Thu, 12 Jan 2006) Astronomers think they might have found a "dark galaxy", that has no stars and emits no light. Although the galaxy itself, located 50 million light years from Earth, is practically invisible, it contains a small amount of neutral hydrogen which emits radio waves. If astronomers are correct, this galaxy contains ten billion times the mass of Sun, but only 1% of this is hydrogen - the rest is dark matter.

http://www.universetoday.com/am/publish/pp...hi.html?1212006

If there is life in that galaxy, just try to imagine how utterly different it probably is from ours.

Astrophysics, abstract
astro-ph/0602271

From: Galina Korotkova Gennadievna [view email]

Date: Mon, 13 Feb 2006 08:03:04 GMT (90kb)

Disturbed isolated galaxies: indicators of a dark galaxy population?

Authors: I.D.Karachentsev, V.E.Karachentseva, W.K.Huchtmeier

Comments: 5 pages, 1 figure. Astronomy and Astrophysics, accepted

We report the results of our search for disturbed (interacting) objects among very isolated galaxies. The inspections of 1050 northern isolated galaxies from KIG and 500 nearby, very isolated galaxies situated in the Local Supercluster yielded five and four strongly disturbed galaxies, respectively. We suggest that the existence of "dark" galaxies explains the observed signs of interaction. This assumption leads to a cosmic abundance of dark galaxies (with the typical masses for luminous galaxies) that is less than ~1/20 the population of visible galaxies.

http://arxiv.org/abs/astro-ph/0602271

[ljk4-1]

General Relativity and Quantum Cosmology, abstract
gr-qc/0601055

From: Lorenzo Iorio [view email]

Date (v1): Sat, 14 Jan 2006 16:11:23 GMT (36kb)
Date (revised v2): Fri, 20 Jan 2006 16:04:50 GMT (37kb)
Date (revised v3): Mon, 13 Feb 2006 16:40:21 GMT (38kb)

What do the orbital motions of the outer planets of the Solar System tell us about the Pioneer anomaly?

Authors: Lorenzo Iorio

Comments: Latex2e, 13 pages, 3 tables, 4 figures, 15 references. Reference added. Stressed the fact that, even by assuming errors in the planetary orbital elements 30 times larger that those published by Pitjeva, the anomalous Pioneer effects on Uranus, Neptune, Pluto still remain well larger and, thus, detectable if present. Small corrections to the numerical values of Table 1 and Table 3: conclusions unchanged

Subj-class: General Relativity and Quantum Cosmology; Space Physics

In this paper we investigate the effects that an anomalous acceleration as that experienced by the Pioneer spacecraft after they passed the 20 AU threshold would induce on the orbital motions of the Solar System planets placed at heliocentric distances of 20 AU or larger as Uranus, Neptune and Pluto. It turns out that such an acceleration, with a magnitude of about 8 X 10^-10 m s^-2, would affect their orbits with secular and short-period signals large enough to be detected with the present-day level of accuracy in orbit determination. The absence of such anomalous signatures in the latest data analyses rules out the possibility that in the region 20-40 AU of the Solar System an anomalous force field inducing a constant and radial acceleration of that size is present.

http://arxiv.org/abs/gr-qc/0601055

[ljk4-1]

General Relativity and Quantum Cosmology, abstract
gr-qc/0602089

From: Kjell Tangen [view email]

Date: Wed, 22 Feb 2006 15:35:17 GMT (92kb)

Could the Pioneer anomaly have a gravitational origin?

Authors: Kjell Tangen

Comments: 9 pages, 1 figure

If the Pioneer anomaly has a gravitational origin, it would, according to the equivalence principle, distort the motions of the planets in the Solar System. Since no anomalous motion of the planets have been detected, it is generally believed that the Pioneer anomaly can not originate from a gravitational source in the Solar System. However, this conclusion becomes less obvious when considering models that either imply modifications to gravity at long range or gravitational sources localized to the outer Solar System, given the uncertainty in the orbital parameters of the outer planets. Following the general assumption that the Pioneer spacecrafts move geodesically in a spherically symmetric spacetime metric, we derive the metric disturbance that is needed in order to account for the Pioneer anomaly. We then analyze the residual effects on the astronomical observables of the outer planets that would arise from this metric disturbance, given an arbitrary metric theory of gravity. The computed residuals are much larger than the observed residuals, and we are lead to the conclusion that the Pioneer anomaly can not originate from a metric disturbance and therefore that the motion of the Pioneer spacecrafts must be non-geodesic. Since our results are model independent, they can be applied to rule out any model of the Pioneer anomaly that implies that the Pioneer spacecrafts move geodesically in a perturbed spacetime metric, regardless of the origin of this metric disturbance.

http://arxiv.org/abs/gr-qc/0602089

[ljk4-1]

General Relativity and Quantum Cosmology, abstract
gr-qc/0511026

From: J. R. Brownstein [view email]

Date (v1): Sun, 6 Nov 2005 02:40:04 GMT (162kb)

Date (revised v2): Fri, 17 Mar 2006 19:20:20 GMT (29kb)

Date (revised v3): Fri, 17 Mar 2006 21:22:19 GMT (29kb)

Gravitational solution to the Pioneer 10/11 anomaly

Authors: J. R. Brownstein, J. W. Moffat

Comments: 12 pages, 3 figures, 2 tables. Accepted for publication in Classical and Quantum Gravity, March 17, 2006

A fully relativistic modified gravitational theory including a fifth force skew symmetric field is fitted to the Pioneer 10/11 anomalous acceleration. The theory allows for a variation with distance scales of the gravitational constant G, the fifth force skew symmetric field coupling strength omega and the mass of the skew symmetric field mu=1/lambda. A fit to the available anomalous acceleration data for the Pioneer 10/11 spacecraft is obtained for a phenomenological representation of the "running" constants and values of the associated parameters are shown to exist that are consistent with fifth force experimental bounds. The fit to the acceleration data is consistent with all current satellite, laser ranging and observations for the inner planets.

http://arxiv.org/abs/gr-qc/0511026

[The Messenger]

General Relativity and Quantum Cosmology, abstract
gr-qc/0511026

From: J. R. Brownstein [view email]

Date (v1): Sun, 6 Nov 2005 02:40:04 GMT (162kb)

Date (revised v2): Fri, 17 Mar 2006 19:20:20 GMT (29kb)

Date (revised v3): Fri, 17 Mar 2006 21:22:19 GMT (29kb)

Gravitational solution to the Pioneer 10/11 anomaly

Authors: J. R. Brownstein, J. W. Moffat

Comments: 12 pages, 3 figures, 2 tables. Accepted for publication in Classical and Quantum Gravity, March 17, 2006

A fully relativistic modified gravitational theory including a fifth force skew symmetric field is fitted to the Pioneer 10/11 anomalous acceleration. The theory allows for a variation with distance scales of the gravitational constant G, the fifth force skew symmetric field coupling strength omega and the mass of the skew symmetric field mu=1/lambda. A fit to the available anomalous acceleration data for the Pioneer 10/11 spacecraft is obtained for a phenomenological representation of the "running" constants and values of the associated parameters are shown to exist that are consistent with fifth force experimental bounds. The fit to the acceleration data is consistent with all current satellite, laser ranging and observations for the inner planets.

http://arxiv.org/abs/gr-qc/0511026

The Tangen and Iorio papers place real constraints upon odd-ball gravitmetric theories which could have accounted for the Pioneer anomaly. This paper is just an exercise in curve fitting. Introducing distant forces that suddenly appear, as needed, to explain observations, is better left to Hobbitary universes. No more dark stuff, please.

[ljk4-1]

Astrophysics, abstract
astro-ph/0502582

From: Michael Makoid . D. [view email]

Date (v1): Mon, 28 Feb 2005 16:46:47 GMT (362kb)

Date (revised v2): Sat, 25 Mar 2006 16:33:55 GMT (368kb)

Ab Initio Calculation of the Anomalous Acceleration of Pioneer 10 In Vacuo

Authors: Russell Anania, Michael Makoid (Creighton University, Omaha, NE.)

Comments: 16 pages with two jpeg figures

The anomalous acceleration of Pioneer 10 is presented as a calculation using a simple optical model. The model is based on the bending of background gravity behind the Sun in the same way that light is bent by the Sun. Structures of ponderable matter about the Solar system, neutron stars, and galaxies are described. Viewable red and blue shiftings of light are predicted.

http://arxiv.org/abs/astro-ph/0502582

[The Messenger]

Astrophysics, abstract
astro-ph/0502582

Authors: Russell Anania, Michael Makoid (Creighton University, Omaha, NE.)


The anomalous acceleration of Pioneer 10 is presented as a calculation using a simple optical model. The model is based on the bending of background gravity behind the Sun in the same way that light is bent by the Sun. Structures of ponderable matter about the Solar system, neutron stars, and galaxies are described. Viewable red and blue shiftings of light are predicted.

http://arxiv.org/abs/astro-ph/0502582

What we are talking about here is matter behaving as if there is a optical density assignable to free space space that is a function of mass - many times greater than predicted by GR

What these two have failed to evaluate, is the effect such a gravitational gradient would have upon the orbits (or the predicted masses) of the planets

[ljk4-1]

Astrophysics, abstract
astro-ph/0603790

From: Ettore Minguzzi [view email]

Date: Wed, 29 Mar 2006 14:44:25 GMT (8kb)

Possible relation between galactic flat rotational curves and the Pioneers' anomalous acceleration

Authors: E. Minguzzi

Comments: Latex2e, 6 pages, no figures

We consider a generic minimal modification of the Newtonian potential, that is a modification that introduces only one additional dimensional parameter. The modified potential depends on a function whose behavior for large and small distances can be fixed in order to obtain respectively (i) galactic flat rotational curves and (ii) a universal constant acceleration independent of the masses of the interacting bodies (Pioneer anomaly). Then using a dimensional argument we show that the Tully-Fisher relation for the maximal rotational velocity of spiral galaxies follows without any further assumptions. This result suggests that the Pioneer anomalous acceleration and the flat rotational curves of galaxies could have a common origin in a modified gravitational theory. The relation of these results with the Modified Newtonian Dynamics (MOND) is discussed.

http://arxiv.org/abs/astro-ph/0603790

[ljk4-1]

General Relativity and Quantum Cosmology, abstract
gr-qc/0601055

From: Lorenzo Iorio [view email]

Date (v1): Sat, 14 Jan 2006 16:11:23 GMT (36kb)
Date (revised v2): Fri, 20 Jan 2006 16:04:50 GMT (37kb)
Date (revised v3): Mon, 13 Feb 2006 16:40:21 GMT (38kb)
Date (revised v4): Sat, 1 Apr 2006 15:06:33 GMT (79kb)

What do the orbital motions of the outer planets of the Solar System tell us about the Pioneer anomaly?

Authors: Lorenzo Iorio, Giuseppe Giudice

Comments: Latex2e, 19 pages, 3 tables, 10 figures, 18 references. Authorship changed; new figures added for a direct comparison with the observable quantities. Accepted for publication in New Astronomy

Subj-class: General Relativity and Quantum Cosmology; Space Physics

In this paper we investigate the effects that an anomalous acceleration as that experienced by the Pioneer spacecraft after they passed the 20 AU threshold would induce on the orbital motions of the Solar System planets placed at heliocentric distances of 20 AU or larger as Uranus, Neptune and Pluto. It turns out that such an acceleration, with a magnitude of 8.74\times 10^-10 m s^-2, would affect their orbits with secular and short-period signals large enough to be detected according to the latest published results by E.V. Pitjeva, even by considering errors up to 30 times larger than those released. The absence of such anomalous signatures in the latest data rules out the possibility that in the region 20-40 AU of the Solar System an anomalous force field inducing a constant and radial acceleration with those characteristics affects the motion of the major planets.

http://arxiv.org/abs/gr-qc/0601055

[ljk4-1]

Paper (*cross-listing*): gr-qc/0604047

Date: Mon, 10 Apr 2006 13:33:42 GMT (601kb)

Title: Does a Teleconnection between Quantum States account for Missing Mass,
Galaxy Ageing, Lensing Anomalies, Supernova Redshift, MOND, and Pioneer
Blueshift?

Authors: Charles Francis

Comments: 20 pages, 12 figs. Submitted to Proc Roy Soc A
\\
Empirical implications of a teleparallel displacement of momentum between
initial and final quantum states, using conformally flat quantum coordinates
are investigated. An exact formulation is possible in an FRW cosmology in which
cosmological redshift is given by 1+z=a_0^2/a^2(t). This is consistent with
current observation for a universe expanding at half the rate and twice as old
as indicated by a linear law, and, in consequence, requiring a quarter of the
critical density for closure. After rescaling Omega so that Omega=1 is critical
density in the teleconnection model, it is found that for given cosmological
parameters, Omega, Omega_k and Omega_Lambda, luminosity distance is a factor
sqrt(1+z) greater than in the corresponding standard model. Best fits to data
from the SuperNova Legacy Survey for a flat space Lambda cosmology is
Omega=1.07 and for a Lambda=0 cosmology, Omega=1.15. It will require many
observations of supernovae at z>1 to eliminate either the standard or
teleconnection magnitude-redshift relation. Quantum coordinates exhibit an
acceleration in time, resulting in the anomalous Pioneer blue-shift and in the
flattening of galaxies' rotation curves. These appear as optical effects and do
not affect classical motions. Milgrom's phenomenological law (MOND) is
precisely obeyed. A no CDM teleconnection model resolves inconsistencies
between galactic profiles found from lensing data, rotation curves and analytic
models of galaxy evolution.

\\ ( http://arXiv.org/abs/gr-qc/0604047 , 601kb)

[edstrick]

In a talk on the Pioneer Anomaly last week at the ISDC (see a few other comments in my post on a Pioneer imaging thread), two things emerged regarding the value of the recovered but not analyzed tracking data.

1.) The anomaly on both Pioneers in the current data does not vary with distance from the sun or time starting at about Uranus' orbit (current data availability) Extending the data much further inward will help search for non-constant forces, particularly ones due to heating of the spacecraft or reflectd sunlight, etc.

2.) Current data says the apparent force is radially inward toward the "inner solar system". The recovered data will enable testing of whether the force is toward the sun, toward the earth, along the spacecraft's axis of rotation (usually but not always exactly toward the earth), or aligned with the spacecrafts velocity vector relative to the sun. In the current data, all these directions are approximately the same and cannot be sorted out.

This will enable testing for and exclusion of a very large number of possible forces acting on the spacecraft. For example, the force of the transmitted radio beam is small but not trivial. That force is always along the spin axis and normally approximately ponited at Earth. For another example, Pioneer 11 was in a low eccentricity orbit around the sun between Jupiter and Saturn examples, and a "drag-like" force would be in it's direction of travel, not radially inward.

[ljk4-1]

Astrophysics, abstract
astro-ph/0504634

From: Andreas Rathke [view email]

Date (v1): Thu, 28 Apr 2005 15:19:02 GMT (163kb)
Date (revised v2): Thu, 1 Jun 2006 08:46:23 GMT (125kb)

Options for a nondedicated mission to test the Pioneer anomaly

Authors: Dario Izzo, Andreas Rathke

Comments: 29 pages, uses AIAA style files. Improved presentation, shortened, some technicalities from v1 omitted, updated references, to appear in Journal of Spacecraft and Rockets

The Doppler-tracking data of the Pioneer 10 and 11 spacecraft show an unmodelled constant acceleration in the direction of the inner Solar System. Serious efforts have been undertaken to find a conventional explanation for this effect, all without success at the time of writing. Hence the effect, commonly dubbed the Pioneer anomaly, is attracting considerable attention. Unfortunately, no other space mission has reached the long-term navigation accuracy to yield an independent test of the effect. To fill this gap we discuss strategies for an experimental verification of the anomaly via an upcoming space mission. Emphasis is put on two plausible scenarios: nondedicated concepts employing either a planetary exploration mission to the outer Solar System or a piggybacked micro-spacecraft to be launched from a mother spacecraft travelling to Saturn or Jupiter. The study analyses the impact of a Pioneer anomaly test on the system and trajectory design for these two paradigms. It is found that both paradigms are capable of verifying the Pioneer anomaly and determine its magnitude at 10% level. Moreover the concepts can discriminate between the most plausible classes of models of the anomaly, a central force, a blueshift of the radio signal and a drag-like force. The necessary adaptions of the system and mission design do not impair the planetary exploration goals of the missions.

http://arxiv.org/abs/astro-ph/0504634