An anomaly in satellite flybys confounds scientists

An anomaly in satellites’ flybys confounds scientists
An artist's rendition of Rosetta probe during a flyby. Credit: ESA/C.Carreau

When space probes, such as Rosetta and Cassini, fly over certain planets and moons in order to gain momentum and travel long distances, their speed changes slightly for an unknown reason. A Spanish researcher has now analysed whether or not a hypothetical gravitomagnetic field could have an influence. However, other factors such as solar radiation, tides, or even relativistic effects or dark matter could be behind this mystery.

Since the beginnings of space exploration, many have gone into a hyperbolic orbit around planets or moons, with the aim of taking advantage of their gravitational energy and go toward their target. However, during this flyby manoeuvre, something makes the spacecraft speed deviate from the scientists' theoretical calculations.

This anomaly has only been detected with a high level of precision in flybys of Earth, due to the availability of monitoring stations such as that of NASA in Robledo de Chabela (Madrid) or that of the European Space Agency in Cebreros (Ávila), which allow for the variations in the spacecrafts' speed to be recorded by means of radars.

Thus, when the Galileo space probe flew over Earth in 1990, an unexpected increase of 4 millimetres per second was detected, as was a similar decrease when it took the same flyby in 1992. Also in 1998, a speed of 13 mm/s above estimates was observed in the spacecraft NEAR, and similar anomalies were repeated in the flybys of Cassini in 1999 (-2 mm/s), and those of the Messenger and Rosetta probes in 2005, with +0.02 mm/s and +1.82 mm/s respectively, the latter arriving just this year at the comet it was directed towards..

"These deviations do not seriously affect the trajectories of the spacecrafts, yet, although they are seemingly small amounts, it is very important to clarify what they are caused by, especially in the current era of precise ," Luis Acedo Rodríguez, physicist at the Polytechnic University of Valencia, tells SINC.

Scientists have still not found any convincing explanation for the phenomenon, although they have put forward a range of hypotheses. One points toward as the cause of the change in speed, while others suggest an influence from magnetic fields or the effect of tides, and there are also even unconventional theories, such as the existence of a halo of trapped by Earth's gravitational pull.

Acedo has proposed an explanation based on a supposed circulating gravitomagnetic field, which would follow the Earth's parallels, an approach that can be used to explain the effects on the majority of flybys. "Einstein's general theory of relativity predicts the existence of a similar field, but in the case of meridians, with this strongly confirmed by experiments such as Gravity Probe B," the researcher comments, although he recognises significant limitations of the model.

"If a force field existed," he explains, "its effects would also be seen in the elliptical orbits of spacecrafts, and should have been detected a long time ago by geodynamic satellites such as LAGEOS or LARES; however, this is not the case, and it is therefore doubtful that a field of this kind could cast a light on this mystery without seriously changing our understanding of Earth's gravity."

With this possibility ruled out, the expert considers, in a study published in Advances in Space Research, that the anomalous behaviour of the probes during their flybys "must originate in something that, although common, we have been unaware of to date, or in an error in the data analysis programs".

The difference in speeds could also have much more serious implications on the understanding of gravity, according to Acedo: "We already have evidence that shows a seemingly small anomaly in astronomical observations leading to new theoretical conceptions, such as the advance of Mercury's perihelion (closest point to the Sun), which was essential in the development of the theory of general relativity. For the case in question, and without ruling out an explanation by means of conventional sources, something similar could occur."

Meanwhile, space probes continue to challenge scientists every time they perform flybys. One of the last was that of the spacecraft Juno in October 2013, from Earth en route to Jupiter. NASA has not yet published data on this journey, but everything indicates that its speed as it flew over our planet once again differed from estimates.


Explore further

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More information: L. Acedo, "The flyby anomaly: A case for strong gravitomagnetism?," Advances in Space Research, Volume 54, Issue 4, 15 August 2014, Pages 788-796, ISSN 0273-1177, dx.doi.org/10.1016/j.asr.2014.04.014.
Provided by Plataforma SINC
Citation: An anomaly in satellite flybys confounds scientists (2014, September 22) retrieved 18 October 2019 from https://phys.org/news/2014-09-anomaly-satellite-flybys-confounds-scientists.html
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Sep 22, 2014
This comment has been removed by a moderator.

Sep 22, 2014
Try General Relativity for gravity. NASA has much incompetence invested in Schwartzchild.

Sep 22, 2014
What about the magnetic fields, of the bodies being passed?
These are not always constant, are they?

Sep 22, 2014
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Sep 22, 2014
What about the magnetic fields, of the bodies being passed?
These are not always constant, are they?


I'm thinking along similar lines. Notwithstanding that a closed-loop trajectory through a magnetic field yields zero energy, if the spacecraft contained magnetic materials possessing a significant Sv (entropy viscosity) factor (per Rutherford's first paper in 1885) then this could cause a KE anomaly between inbound vs outbound legs of the flypast trajectory. For a given spacecraft prone to the effect, its magnitude would be greater for circum-polar orbits compared to equatorial ones.

This wouldn't arise in shielding materials, since they'd have high permeability, low coercivity and negligible remanance, and hence minimal Sv. However structural components - perhaps something as seemingly insignificant as some types of nuts and bolts - could be manifesting the asymmetry..

Sep 22, 2014
Is their velocity being changed in multiple axis, or only increasing/decreasing along the original flight trajectory?

This doesn't seem to be a big enough effect to be from a a Dark Matter tale wake. Jupiter ought to displace enormous amounts of the stuff, changing the density of ti's distribution in the region it passes dramatically, like a boat in water.

If a satellite were to hit a small cloud of DM it should be effected about equally either way, but if it were to fly-by the cloud at just the right timing, it could be accelerated more in one direction than the other.

Tail wakes from Venus and Earth would be much smaller than Jupiter, but there's supposed to be 4 times as much of this stuff as ordinary matter.

Still, it would be interesting to model. I just got done arguing AGAINST DM because of not seeing enough purturbations, I'm not sure this is anywhere near enough either.

they coudl change speed due to gravitational mass of coronal mass ejections too, but by how much? .

Sep 22, 2014
There is another problem with any DM theory:

The tail wake's kicked up by planets would alter lunar orbits if they passed through the other planet's orbits, and this we certainly do not see.

I vote for ordinary effects of ordinary matter, or assymetric radiation/heat loss effects.

Sep 22, 2014
I vote for ordinary effects.


Sorry Cher, there ain't nothing ordinary about any of your effects. Not quite as silly as the pine cone stem tale, but it's still way up there on the silly scale. Considering those scientist-Skippys are trained professionals and probably know a little bit more about it than you do about pine cone stems.

Sep 22, 2014
I vote for ordinary effects.


Sorry Cher, there ain't nothing ordinary about any of your effects. Not quite as silly as the pine cone stem tale, but it's still way up there on the silly scale. Considering those scientist-Skippys are trained professionals and probably know a little bit more about it than you do about pine cone stems.


No, they don't know what they're talking about.

They admit they can't explain it, moron. Thus they don't know what they're talking about.

That's the whole damn point of the article.

Sep 22, 2014
Design and experiment:

At least 6 orbiters are needed to orbit the solar system along the 3 different major planes.

Setup:

2 orbiters in each plane, at opposite ends of the designed orbit on that plane, which is to say each pair oppose one another.

Experiment:
If something "physical" and unknown in the solar system is causing this then we would expect slightly different results of acceleration or decelleration of the probes, depending on which ones pass closest to the "something. The reason you need two per plane is you want to see if there is something special about different planes (there isn't supposed to be), or whether there is something special about "timing".

If there is something special about "timing" so that each of the pair is effected differently within the same orbit, then there is either an unknown object in the inner to middle solar system, or an unknown "force" at play (not necessarily "fundamental") or there is just that much margin of error in the instruments.


Sep 22, 2014
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Sep 22, 2014
They admit they can't explain it, moron. Thus they don't know what they're talking about.


Admitting you don't know something only means you know enough not to offer up some silly made up foolishment that sounds like a person with the mental condition said it.

That's the whole damn point of the article.


So some no-name-Skippy is going to tell them what the answer is, is that the point I missed me? The same Skippy who made up the pine cone stem tale? Was that part of the point of the article?

Sep 22, 2014
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Sep 22, 2014
This comment has been removed by a moderator.

Sep 22, 2014
The same Skippy who made up the pine cone stem tale?
The silly "Skippy" labeling is actually your least problem Ira - your problem rather is, you don't understand the physics at all, but you're masking it with loud intolerance of everyone, who is trying to think independently here. As the result, your posts lack matter of fact arguments, as they're solely composed of appeal to authority fallacies and personal attacks. In addition, the wannabe joking and twaddling of yours (in the way, which you apparently believe makes you interesting for others) is doing a silly Facebook and social club from PO discussions. Sorry, but the blind following of crowd and fight against everyone, who isn't going with crowds will not make an authority of you automatically. It's just an evidence of your social insecureness.

Well said. Aunt Ira is an idiot!

Sep 22, 2014
So some no-name-Skippy is going to tell them what the answer is, is that the point I missed me? The same Skippy who made up the pine cone stem tale? Was that part of the point of the article?


I didn't make that up. There are at least 7 living eye witnesses that I know for him making that difficulty level of shot on multiple occasions. Himself, my mother, their older brother, my older brother, me, his step-son, and a former neighbor.

====

Everybody's a no-name until they aren't.


Sep 22, 2014
I didn't make that up.


Cher, have you ever looked at a pine cone STEM from a 100 yards? Are you sure that he was not shooting at a billboard sized picture of the pine cone stem?

Boug, do you realize a pine cone STEM is about a 1/16 inch the diameter, and only about the 1/4 inch long? That's why I ask you if you ever seen a pine cone You said he hit him without the scope using just the iron sights without resting at 100 yards.

I live in the swamps for 42 years now and know more shooters than I don't how many, really good shooters who shoot like you have never did see again. Nobody can shoot like that without the really good scope and rest on something.

Cher you need to stop your self before say the lie part and think, "Do this make sense to anybody but a couyon, or is he something I need to work on some more before I tell him?

Sep 22, 2014
Look man, I got it.

It's left-over ions from the space aliens engines as they pass by.

I figure, with all the sightings, there has to be alien "con-trails" out there somewhere.

P.S.

NOW I'm just trolling uncle fester there, nobody else have a fit.

Sep 22, 2014
I didn't make that up.


Cher, have you ever looked at a pine cone STEM from a 100 yards? Are you sure that he was not shooting at a billboard sized picture of the pine cone stem?

Boug, do you realize a pine cone STEM is about a 1/16 inch the diameter, and only about the 1/4 inch long? That's why I ask you if you ever seen a pine cone You said he hit him without the scope using just the iron sights without resting at 100 yards.

I live in the swamps for 42 years now and know more shooters than I don't how many, really good shooters who shoot like you have never did see again.


The time I saw him doing it, he was shooting the pine cones from a sitting position,a nd the witnesses were myself, brother, the neighbor, and his step-son.

I've seen him put a round back in the casing from a standing position though, and my older brother has seen it twice.

I've also seen a similar shot made about 16 years ago at a marksmanship competion: 2 rounds in one hole.

Sep 22, 2014


I live in the swamps for 42 years now and know more shooters than I don't how many, really good shooters who shoot like you have never did see again. Nobody can shoot like that without the really good scope and rest on something.

LOL! That explains Aunt Iras posts!

Sep 22, 2014
@ Delicious-Skippy. I know that means something because you wrote him there. But what does that supposed to mean? I may be the ignorant coonass, but I can make postums with more than five words so peoples can maybe see what I getting at without trying to guess what is on my mind. Can you do that?

Sep 22, 2014
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Sep 23, 2014
No mention of charged bodies (probes, comet, asteroids, etc...) and their effects or how they are affected by the various electric and magnetic fields they move through. In addition to the large scale planetary/solar electric and magnetic fields there are also the more localized electric DL's, waves, and currents, etc... which add immense complexity to the equation. It's a whole lot more than gravity and masses.

yep
Sep 23, 2014
Who needs dark matter when electric fields can easily account for these anomalies. These fields may also be what is being mistaken for the cosmic microwave background when it is really a local interstellar microwave background being emitted.

Sep 23, 2014
No mention of charged bodies (probes, comet, asteroids, etc...) and their effects or how they are affected by the various electric and magnetic fields they move through. In addition to the large scale planetary/solar electric and magnetic fields there are also the more localized electric DL's, waves, and currents, etc... which add immense complexity to the equation. It's a whole lot more than gravity and masses.

No mention of Turtle Elephant Space either. That immense elephant eructation plays utter havoc with orbital mechanics, especially just after they've fed. Complicates things terrifically.

Sep 23, 2014
There is another problem with any DM theory:

The tail wake's kicked up by planets would alter lunar orbits if they passed through the other planet's orbits, and this we certainly do not see.

I vote for ordinary effects of ordinary matter, or assymetric radiation/heat loss effects.
Ah jeez Lrrkrr thinks DM is dense aether now. This is from the guy who thinks a planets direction of rotation affects its migration.

Do you see any tail wakes from moons in saturns rings Lrrkrrr?

Sep 23, 2014
This comment has been removed by a moderator.

Sep 23, 2014
This is from the guy who thinks a planets direction of rotation affects its migration.
Why not? We already have an indicia of such a migration from http://connection...objects. Maybe the interaction with DM is the culprit here.
Because I looked it up and posted the FACTS for him. Why dont you try it?

Sep 24, 2014
Time dilation


Sep 24, 2014
This comment has been removed by a moderator.

Sep 24, 2014
There will always be a variation when approximations are used. Specific local gravity, i.e. the forces of gravity in effect at a given moment in time and location in space, i.e. collectively points along the path of the orbiting object, will vary. The only way to make better predictions is to have a more accurate model. To have a more accurate model we need more accurate measurements and this is where we run out of money. You can measure all the irregularities in the surface of the object, but you still won't have a clue to the fluid dynamics going on beneath the surface. I think we just accept the variation and counter it with adjustments on the fly.

Sep 24, 2014
I looked it up and posted the FACTS for him
Which facts in which post? You just posted two posts into this thread and none of them contains some fact - only the nonscientific subjective dismissals. Maybe you're living in alternative reality. You people are completely crazy. Do you really believe, that the calling "Nope, you're wrong" is presentation of facts?
Well obviously it wasn't in THIS thread was it?

I'm not going to post a link for you. Instead I'm going to explain how you can find one for yourself. Go to google, type in 'planetary migration', and hit 'enter'. You will then see a list of links for your enlightenment. Try the wiki one.

No don't thank me. Instead please send a modest donation to 'retards anonymous'.

Sep 24, 2014
I would guess the altitude of the flyby would have to be extremely precise to estimate within mm/second how fast the spacecraft should be going. Maybe they flew over a mountain range on part of the flyby that sped it up or a deep valley that slowed it down?

Oct 29, 2014
"Scientists have known about global warming for decades. It's real. Let's move on to what we can do about it." http://clmtr.lt/c/Ozw0cc0cMJ

yep
Oct 31, 2014
There is that dang elephant again.
http://arxiv.org/abs/1409.3096

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