Talk:Flyby anomaly

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JPL's empirical formula and the Nov. 2007 Rosetta flyby

According to "Anomalous Orbital-Energy Changes Observed during Spacecraft Flybys of Earth" by John D. Anderson, James K. Campbell, John E. Ekelund, Jordan Ellis, and James F. Jordan[1], the authors made a prediction about the magnitude of the anomaly that Rosetta would experience during its November 13, 2007 flyby.

That was six months ago. By now, there should be some news about whether the predicion was accurate, but I haven't heard anything. Either way, it would be interesting. If you know something about this, please add it to the article.199.46.199.232 (talk) 21:46, 23 May 2008 (UTC)[reply]

No anomaly was observed during the last Rosetta flyby. —Preceding unsigned comment added by 145.238.204.239 (talk) 10:08, 27 May 2010 (UTC)[reply]

Indeed, no anomaly was observed during the 2009 Rosetta flyby. This doesn't contradict Anderson's equation, which predicted an anomaly smaller than 1mm/s. Lacking the data for the Rosetta flyby myself I can't perform the calculations to see just how wrong (or right) Anderson's formula is. I updated the article to say there was no anomaly detected, but made no mention of Anderson's formula (yet). Banedon (talk) 04:26, 10 March 2011 (UTC)[reply]

Cassini

The number for Cassini is incorrect. Cassini measured no effect, and they looked for it too. User:137:78:78:184 20:21 !9 August 2006

Date & IP address added for previous post. Wwheaton (talk) 20:52, 13 November 2009 (UTC)[reply]

Comparison to Pioneer anomaly

"Satellites" should be "space probes" or "spacecrafts". Also it doesn't seem right to claim that the Pioneer Anomaly is "very similar" - Pioneer Anomaly means change in acceleration while FA means change in velocity. Also we have no idea about causes, so they may be completely unrelated. Mandevil (talk) 14:30, 5 March 2008 (UTC)[reply]

How can you affect an object's velocity without affecting its acceleration? The two are, by definition, directly linked to each other.199.46.199.232 (talk) 21:46, 23 May 2008 (UTC)[reply]


Pure speculation on my part...

...But perhaps it has to do with the indications (recently mentioned on NOVA, on PBS) of a magnetic reversal soon to hit the planet within the next century. The magnetic field has been weakening, is the only extreme change I can see in Earth to cause a change in energy output and subsequent impact on incoming spacecraft. --Chr.K. 01:49, 12 November 2006 (UTC)[reply]

Units

What is 66mHz supposed to be- milli or mega? If the former it's so rarely used that it could usefully be specified explicitly. MarkMLl (talk) 14:44, 23 September 2008 (UTC)[reply]

Trajectories

Is it just me or is this still incomplete data in the table? I think the flyby trajectory angle around a sphere has two dimensions: towards equator (0 degrees should mean "following latitudes", 90 degrees "following longitudes", more than means backwards direction), and latitude of the perigee (where is the closest point), or alternatively angle of the perigee in the orbit plane vs. equator. We have the first parameter, but with the theory that it depends on inbound/outbound angle, we need the perigee latitude as well. Whoever has access to the paper with the current working hypothesis (it's just an equation, no explanation why) should be able to extract that from the paper. —Preceding unsigned comment added by Bernd Paysan (talk • contribs) 23:51, 10 January 2009 (UTC)[reply]

Flyby anomaly may be a radar anomaly

Eg See:

Resolving Spacecraft Earth-Flyby Anomalies with Measured Light Speed Anisotropy http://arxiv.org/abs/0804.0039

Doppler shift observations of spacecraft, such as Galileo, NEAR, Cassini, Rosetta and MESSENGER in earth flybys, have all revealed unexplained speed `anomalies' - that the doppler-shift determined speeds are inconsistent with expected speeds. Here it is shown that these speed anomalies are not real and are actually the result of using an incorrect relationship between the observed doppler shift and the speed of the spacecraft - a relationship based on the assumption that the speed of light is isotropic in all frames, i.e. invariant. Taking account of the repeatedly measured light-speed anisotropy the anomalies are resolved. The Pioneer 10/11 anomalies are discussed, but not resolved. The spacecraft observations demonstrate again that the speed of light is not invariant, and is isotropic only with respect to a dynamical 3-space. The existing doppler shift data also offers a resource to characterise a new form of gravitational waves, the dynamical 3-space turbulence, that has also been detected by other techniques. —Preceding unsigned comment added by 122.105.86.2 (talk) 12:06, 5 July 2009 (UTC)[reply]

This paper is not peer reviewed yet. None of the references for other measurements of an anisotropy of light speed is to a well-respected source. The explanation how this does not contradict special relativity theory sounds shady to me. I would not trust this paper, unless it gets published in a respected journal. I also found this: http://prl.aps.org/abstract/PRL/v60/i2/p81_1 The anistropy of light speed does not exist. —Preceding unsigned comment added by 134.36.15.74 (talk) 12:13, 18 January 2011 (UTC) (sorry I do not know the standard way to post a comment on this)[reply]

Error bars missing

The table lacks the 1-σ error intervals for row "Speed increment at perigee, mm/s" in columns Cassini, Messenger, Rosetta-II. Could someone please look them up? Thx Paradoctor (talk) 16:33, 22 November 2009 (UTC)[reply]

Thanks for the quick response, but I was talking about "increment at perigee". The values listed are "≈−0.2", "~0" and "~0", which is uninformative at best. Paradoctor (talk) 17:30, 22 November 2009 (UTC)[reply]

But one is easily derived from the other, since they are related by a common energy gain. For these small dvs, the delta V at perigee is equal to the delta V at infinity time the ratio (speed at infinity/speed at perigee). So these are easily computed from the other table entries. Also, the speeds at infinity and perigee are very well known, so the error bars are related in the exact same way. This can be verified by checking the other entries, where these relationships hold. So I updated the missing entries where the data is published. LouScheffer (talk) 00:47, 23 November 2009 (UTC)[reply]
"easily derived" assumes that one is aware of this relationship. I wasn't, and that's probably true for the vast majority of the ~100 readers each day. Besides, what good is a lookup table if you have to calculate the values yourself? ;) Aside from that, Thank you for updating the table. Paradoctor (talk) 10:21, 23 November 2009 (UTC)[reply]

Need for more data

The table regarding the respective data of the fly-by satellites doesn't give any indication of the direction of approach regarding the earth's rotation. For instance was Cassini approaching from a 'retrograde' direction.

Also, there is no data as to the relative position and direction of the moon. Was our moon's varying gravitational influence assisting or reducing the probe's velocity?


Nick Summers —Preceding unsigned comment added by 80.175.186.68 (talk) 12:53, 22 January 2010 (UTC)[reply]

I'd also like to have more data, including relative position/direction to the sun. The full set of data should be fairly easy to give: point on earth's surface for the object's closest distance, distance and speed at that point, direction vs. equator, exact time and date, and of course the effect itself (delta in speed). The rest is then easy to calculate. --Bernd (talk) 20:53, 23 January 2010 (UTC)[reply]

You can try the JPL web interface to solar system and spacecraft data, at [2] .This is an interface into their navigation software, and can give you all the info you want, and much more. LouScheffer (talk) 21:28, 23 January 2010 (UTC)[reply]

Effect of tides on earth gravitation field and hence on flyby speed

Speculation, but as I can find no other information on this issue, here is my postulation. "The tide pattern around the planet effects the near gravitation field by a small amount. Perhaps 1 in 1E8 from high tide to low tide at the earth's surface attenuating by the square of distance into space" This may account for the flyby anomaly and its variation case to case. — Preceding unsigned comment added by Alansoz (talk • contribs) 00:26, 28 October 2011 (UTC)[reply]

not linked to Pioneer Anomaly

Since the Pioneer anomaly is solved since April 2012 (asymmetrical heat radiation from the nuclear reactor), it cannot be linked to the Flyby anomaly. — Preceding unsigned comment added by 81.242.64.83 (talk) 21:21, 18 May 2012 (UTC) I disagree, for the self called thermal emission "definitive" solution, has still to compete with the General Relativistic treatment, as in the references by Marcelo Samuel Berman, and also with F.M.Gomide (see in the main article).The thermal emission relies on computer modelling and numerical calculations, while Berman´s is just plain Physics, and a Rotational state in the Universe, that has been actually already observed by astronomers and astrophysicists. — Preceding unsigned comment added by 177.4.112.185 (talk) 01:23, 15 November 2012 (UTC)[reply]

Warning-General Relativity and Relativistic Cosmology Solved this Anomaly with Universal Rotation

I have to warn you that Prof. Marcelo Samuel Berman has already published the solution of FlyBys, with General Relativity.His information seems to have been deleted from the main page, by ignorant space engineers, linked to Slava Turyshev, and Claus Lämmerzhal, whose secret desire is getting a Nobel prize, with the Pioneer Anomaly, and this one, unduly.[1] 189.73.12.65 (talk) 04:51, 28 December 2012 (UTC)[reply]

References

  1. ISBN 978-1-61942-164-6
See also MarceloBerman SPI case. - DVdm (talk) 12:51, 29 December 2012 (UTC)[reply]

Can the flyby anomaly be attributed to earth-bound dark matter?

These two papesr describe another possible solution to the enigma which isn't mentioned in the article: http://arxiv.org/abs/0805.2895 and http://arxiv.org/abs/1112.5426

In addition I've noticed that Terrestrial Gamma Ray Flashes detected by NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms. Acting like enormous particle accelerators, the storms can emit gamma-ray flashes, called TGFs, and high-energy electrons and positrons. Scientists now think that most TGFs produce particle beams and antimatter. The map of where these antimatter producing thunderstorms occur shows a distribution around the Earth's equatorial regions which fits with the Flyby Anomaly spacecraft trajectory data. The beam is also narrow and concentrated to a relatively small area which lends itself to a possible solution for the intermittently observed effect. 176.24.226.120 (talk) 11:22, 5 July 2013 (UTC) Alan Lowey.[reply]

New Mission Will Explore Bizarre Gravitational Anomaly Around Earth

This should be included in an updated article: http://www.popsci.com/technology/article/2012-11/new-satellite-could-explain-bizarre-flyby-anomaly-spacecraft-slingshot-around-earth

OK, added link to academic article referenced in the Pop Sci article.

Juno Flyby Data

It's been two months since the Juno flyby, is there any data from the flyby related to the anomaly? — Preceding unsigned comment added by Ac3raven (talk • contribs) 01:11, 17 December 2013 (UTC)[reply]

The Flyby anomaly likely does not exist

Last four flybys performed by Messenger, Rosetta-II, Rosetta-III and Juno from Aug 2005 to Oct 2013 showed no anomaly. Cassini (Aug 1999) and Rosetta-I (March 2005) presented moderate anomalies while large anomalies were recorded long ago between Dec 1990 and Jan 1998 and their cause is likely an error of some kind that has been corrected as the time passed and an increase effort has been invested into measuring the anomaly more and more carefully.(70.83.114.138 (talk) 20:51, 27 February 2014 (UTC))[reply]

We need sources lest we run afoul of
WP:SYN. Paradoctor (talk) 21:53, 27 February 2014 (UTC)[reply
]
The sources are the last four flybys spreading an interval of 8 years (2005-2013). The last measurements simply do not confirm any anomaly. (When early results obtained in some tests are not backed by latter experiments the most likely conclusion is that there was something wrong with the first experiments.) At least one significant anomaly has to be detected in order to seriously push forward with the investigation of this claimed phenomenon.(70.83.114.138 (talk) 00:21, 28 February 2014 (UTC))[reply]
"Do not combine material from multiple sources to reach or imply a conclusion not explicitly stated by any of the sources." Paradoctor (talk) 01:15, 28 February 2014 (UTC)[reply]

Azimuthally Symmetric Theory of Gravitation (ASTG) is advertised only by its author

Quote from the Wikipedia article about Flyby anomaly: The anomaly may be due to the rotation of the Earth. This rotation induces an azimuthally symmetric gravitational field.[10]

Azimuthally Symmetric Theory of Gravitation (ASTG) is the personal creation of G. G. Nyambuya (http://arxiv.org/find/physics/1/au:+Nyambuya_G/0/1/0/all/0/1) and not something taken seriously by scientists. A search with Google finds that only Nyambuya talks about this theory and nobody else. He is the one who inserted a reference about himself in Wikipedia in order to advertise his research. Unless one finds a few professors or researchers who support ASTG I do not see any reason to quote it.(70.83.114.138 (talk) 07:56, 28 February 2014 (UTC))[reply]

Should paper by McColloch be cited?

This paper may well be (almost surely is) wrong, but that's not the criteria for Wikipedia. It is definitely notable. It's published in a fairly reputable journal and has 23 cites. At least two of them (both by experts in the field) indicate they at least considered this model.

  • Iorio states: Among various explanations in terms of non-conventional physics put forth so far, McCulloch in [15] proposed a mechanism based on the hypothesis that inertia is due to a form of Unruh radiation and varies with acceleration due to a Hubble-scale Casimir effect. It qualitatively reproduces the latitude-dependence of eq. (11) and is quantitatively in agreement with three of the six measured flybys."
  • Lammerzahl, in the book Mass and Motion in General Relativity has the chapter Testing Basic Laws of Gravitation – Are Our Postulates on Dynamics and Gravitation Supported by Experimental Evidence?, where he states "There are also more hypothetical considerations: in [118, 119] a model was introduced in which the inertial mass experiences a modification that depends on the Hubble scale and the acceleration of a body. Within this model, the additional term accounts for the Pioneer anomaly and also gives a modification of the velocities of spacecraft during a flyby."

Again, I am not saying the model is correct. But it is notable. If other editors could weigh in on this conclusion, that would be great. LouScheffer (talk) 04:09, 19 September 2015 (UTC)[reply]

Having an entire section to this obscure and basically unnecessary model that was made initially to explain the Pioneer anomaly and now is just crowbarred in to a new suggestion is essentially promoting one out of dozens if not hundreds of fringe proposals. Neither of the citations to this particular paper are what would be necessary to establish the
WP:PROMINENCE we would require to include a section. The journals that Iorio is published in are obscure and the off-handed mention by Lammerzahl does not rise to the level of serious consideration we ask for fringe theories. jps (talk) 10:55, 19 September 2015 (UTC)[reply
]
Lorenzo Iorio is member of good standing in the conventional physics community. Looking at the first page of google scholar results for 'Iorio L relativity', you see 10 papers, all published in reputable places, such as three in
Astronomy and Astrophysics, with an average of more than 50 cites. He is definitely not a crank. And if you ask an expert "What do you think of McConnell's theory?", and his answer is "I think it's bogus", that's evidence of notability, which is what counts in Wikipedia. (If they answer "Huh? What theory?" then that could be evidence of crank-ness. LouScheffer (talk
)
Iorio's publication record is not what is up for discussion here. The fact is that the papers which cite McCulloch's paper are not published in journals of high enough quality for them to serve as decent independent notice. We need more than just obscure citations. jps (talk) 15:30, 19 September 2015 (UTC)[reply]
His publication record shows he is a reputable member of the conventional physics community. And he knows of McCulloch't theory, enough to discuss it. That means is notable.
Also, for this topic, the other proposals have 12 and 35 cites. This has 23, so in line with other ideas. Again, not saying it is right, but it is notable. LouScheffer (talk) 18:30, 4 October 2015 (UTC)[reply]
It doesn't matter if Iorio knows about McCulloch's theory. If I walk down the hall and tell some of my notable buddies in the astrophysics about McCulloch's theory, they'll know about it too. The point is that the reference is in an obscure journal -- it's not in a high-quality journal. The citation count attempt to claim prominence for the idea is not convincing at all. If anything, this just indicates that this particular article probably needs a clean-up to remove a lot of the fringe physics which tends to creep into articles that accept peculiar ideas. jps (talk) 18:57, 4 October 2015 (UTC)[reply]
" If I walk down the hall and tell some of my notable buddies in the astrophysics about McCulloch's theory, they'll know about it too.". This is very definition of notable. Wikipedia does not distinguish right from wrong, mainstream from fringe, since these require judgement. What Wikipedia *is* based on is notability, which can be easily verified. Published in a reputable journal? Check. Referred to by other papers? Check. Known to the experts in the field? Check. So it should be mentioned. Right or wrong, this the criterium for inclusion in Wikipedia. LouScheffer (talk) 19:23, 10 October 2015 (UTC)[reply]

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I've cracked it!

Or not, but what if there is no acceleration? but one is observed down here on earth due to time dilation. remember the experiment where you take two atomic clocks and set them at the exact same time, put one in a plane, and send it around the world, and the other stays on earth. when the plane returns, the two clocks are no longer showing the exact same time, and one is ahead (or behind depending which clock you look at) by a certain amount. maybe this anomaly is the explanation for the flybys anomaly. there is no acceleration, its caused by time dilation due to getting further away from the earths gravity. the gravity of a black hole supposedly messes around with time aswell. so why wouldn't all gravity have this effect? ....ok so i just read the full article, it seems what im talking about is already a proposed possible explanation, and the thing with the planes is something called the Hafele Keating experiment. it seems like the most logical explanation of why it happens, and with time being relative to the observer, why from MESSENGERS perspective there seemed like no anomaly. i dont know, im just a layman with a high school education (barely) and a crappy IQ of 131, so i'm just giving the explanation that makes sense to me based on the odd random info about things that i know, but i realise there is also a ton of stuff i don't know, and i could be wrong. it just makes sense to me as the reason why. the ISS is 0.007 secs behind earth every 6 months due to time dilation. and they have to adjust their clocks every six months thanks to the good old space time curvature thingamabob. but like i said i could be wrong, i mean for one, i also have a theory about reaching the speed of light, just how to spin something that fast, not travel that fast in a straight line, i know crazy right? so its up to you if you think im right about time dilation being the reason. — Preceding unsigned comment added by D0S81 (talk • contribs) 03:09, 8 March 2018 (UTC)[reply]

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