Slowing of a satellite sent by Nasa

[ananthu]

There is a story doing round in e-mails and FB recently.

The story is this: A satellite sent by Nasa, while going round the globe, slows down automatically when it crosses a particular spot over the Saneeswarar temple (a Hindu temple dedicated for Saturn), in Thirunallar, Tamil nadu, India. the story further says that Nasa has also officially accepted such an effect, sent some of its scientists to the said place and could not find a possible scientific explanation and that they simply returned saying 'it is a miracle'.
The story therefore concludes that temple of the lord Saneeswarar has been correctly built at a place by the ancient people knowing that a heavy dose of UV rays are falling on the temple from space on a particular day every 30 months during the day of "sani peyarchi"(Shifting of the position of the planet from one zodiac to the other). The same UV rays should be responsible of the slowing down of the satellite whenever it crosses that place.
Though I do not believe the story, such circulation of news in the name of NASA may misguide the younger generation and make them prey for superstitious beliefs.
So, it is the duty of the scientific community to dispel such doubts.

So, please tell me whether any such observation was made by Nasa in the recent past? Is there any truth in the above circulated story? What could be the background for such messages in the name of Nasa?

 

[dacruick]

I don't know but it sounds like a load of BS

 

[ananthu]

What is BS?

 

[dacruick]

That NASA went there with a team of scientists who came back with the answer "its a miracle". How would going to India help them figure out what a satellite was doing in space? Would they not just sent a probe up to space to gather UV data if that UV radiation was slowing a satellite down?

 

[Ryan_m_b]

After spending some time googling I can't find any evidence of this aside from people asking questions on forums asking "There's an article that says..." but I have yet to find a link to the original source. Nor the name of the satellite or any record of NASA scientists saying it's a miracle (which pretty much shows that the story is rubbish). Unless you can find an original source there's not much to suggest that this isn't anything more than an internet myth.

The fact that it mentions ideas of ancient mystics building a temple to harvest a miraculous effect that scientists have only just discovered lend even more credence that it's a crazy myth.

 

[dacruick]

Not only does Ryan_m_b's research point to it being a myth, but so does common sense.

 

[mjacobsca]

What is BS?

Ananthu, BS is an English acronym for some bad language. I don't want to get flagged, so I won't repeat it, but it essentially means "load of crap". :)

 

[Ryan_m_b]

It seems to be a spam email written in Tamil that was sent around last Christmas, this is (apparently) a translation to English. The reaction of the Yahoo group members to this claim is exactly what you would expect.

 

[tony873004]

... Is there any truth...?

Some. Satellites should slow over this region, and NASA has accepted it.

The temple is in Southern India. This region has a gravity anomaly of about 60 mgal less than the planet-wide average. With the Earth not pulling as hard over this region, the satellite rises into a higher, slower orbit. And NASA has officially accepted it. This, along with Earth's other gravity anomalies are taken into account in satellite tracking software, including the free programs you can download to predict when the ISS and other satellite will be visible in your area. There is a long list of coefficients in these models to account for Earth's mass concentrations (Mascons).

It's very likely that scientists have traveled to this and other regions to study Earth's gravity anomalies. But I doubt any scientists called it a miracle. They have a pretty good understanding of how mascons relate to Earth's continental features. Even if they didn't, scientists create and test hypothesises, and modify their hypothesises when they can't figure out what's going on. They don't just declare a miracle and call it a day.

Google for a map of Earth's gravity field, and you'll see that this region is not alone. Earth's gravity field is very lumpy.

 

[phinds]

the story further says that Nasa has also officially accepted such an effect, sent some of its scientists to the said place and could not find a possible scientific explanation and that they simply returned saying 'it is a miracle'.

That's utterly absurd. As previously said, it's just BS.

ananthu, when you start believing silly nonsense like that, the internet has affected your brain via the old computer adage "garbage in, garbage out".

Nasa scientist do not believe in "miracles".

 

[Ryan_m_b]

Some. Satellites should slow over this region, and NASA has accepted...

Do you have any reference? If so this may be the grain of truth in this rumour.

 

[tony873004]

Do you have any reference? If so this may be the grain of truth in this rumour.

That's what I figured. It probably started as a trivial but true fact, and the story grew from there.

For references, just Google gravity map. There's pleanty of them on Google Images. Satellites slowing down and speeding up is how they built these gravity maps. See here: http://en.wikipedia.org/wiki/Gravity_Recovery_and_Climate_Experiment and look at the section entitled "How GRACE Works"

Also see here: http://satobs.org/faq/Chapter-05.txt for an explanation of Mascons and how they affect a satellite's orbit.

 

[BobG]

Do you have any reference? If so this may be the grain of truth in this rumour.

To say satellites slow down over this region isn't quite accurate. However, it is accurate that geosynchronous statellites tend to drift towards this region of the Earth (about 75 degrees East longitude). They drift towards this region regardless of which side they started out on.

Similarly, geosynchronous satellites also drift towards 105 degrees West longitude, but legend has it that the reason for this is that I happen to live near that particular longitude.

Irregularities in the Earth's gravity field effectively create bulges near 11 degrees longitude and 162 degrees East longitude (or at least putting the bulges there allows us to model the perturbations mathematically). Having a bulge in front of the satellite would 'speed it up' (although add energy would be a better term). Because speeding a satellite up increases its orbital size, and therefore its orbital period, it falls behind the Earth's motion and drifts towards the 'valleys'. Having a bulge behind the satellite 'slows it down'. Slowing a satellite down likewise decreases its orbital period causing it to also drift towards one of the 'valleys' from the opposite side.

Technically, all satellites are affected by irregularities in the Earth's gravity field, but this particular perturbation is about a 65 meter difference. Thus, it's only pertinent to satellites that are exposed to the same part of the Earth 24 hours a day, 7 days a week. It may be a small perturbation, but its effect builds up over time.

Thirunallar sits at 80 degrees East longitude, so it isn't a perfect fit for a legend like this, but it does have a cool temple.

 

[D H]

To say satellites slow down over this region isn't quite accurate. However, it is accurate that geosynchronous statellites tend to drift towards this region of the Earth (about 75 degrees East longitude). They drift towards this region regardless of which side they started out on. ... Thirunallar sits at 80 degrees East longitude, so it isn't a perfect fit for a legend like this, but it does have a cool temple.

So, yes, there is a grain of truth to this. BobG is talking about the J₂₂ sectorial harmonic, which is the primary culprit for these stability points.

The Earth is not a perfect sphere. A better approximation is an oblate spheroid. The mass distribution is not exactly that of an oblate spheroid, either. One way to look at the J₂₂ sectorial harmonic is that Eurasia+Africa, the Pacific, the Americas, and the Atlantic create for a gravitational potential that depends on longitude. Think of quartering an orange. The J₂₂ sectorial harmonic represents the fact that these quarter chunks of the Earth have slightly different mass distributions.

One little temple, or even a very, very big temple, doesn't do the trick. The email reported in the OP is based on coincidence.

Similarly, geosynchronous satellites also drift towards 105 degrees West longitude, but legend has it that the reason for this is that I happen to live near that particular longitude.

Are you saying you need to go on a diet?

 

[ananthu]

Thanks for all the answers.

Sorry that I didn't visit this site for quite some time.

What I understand from all these discussions is that the gravitational anomalies at different places on the Earth may cause the phenomenon of speeding up or slowing down of a satellite in its orbit. It has nothing to do with the "Saturn Effect" as the believers spread this sort of 'BS'(!)

But Nasa has not either officially accepted or denied such an effect near this temple in its website.

Even if it is an internet hoax, it will be better for the big organisations like Nasa to come out with scientific explanations for such phenomenon, as it will dispel superstitions from the minds of general public as the electronic media is so powerful that it projects false ideas as truths using the banner of genuine science organisations.

Also on this coming Dec 21st, lakhs of people are going to gather in this temple to take a holy dip in a pond, as on that day the Saturn is believed to be shifting from one zodiac into another zodiac.Certainly the above internet story may get a new lease of life and do another round with more myths with the unsolicited blessing of none other than NASA!

 

[Ryan_m_b]

But Nasa has not either officially accepted or denied such an effect near this temple in its website.

Even if it is an internet hoax, it will be better for the big organisations like Nasa to come out with scientific explanations for such phenomenon, as it will dispel superstitions from the minds of general public as the electronic media is so powerful that it projects false ideas as truths using the banner of genuine science organisations.

There's a youtube user I like who has named a law after himself;

Myths are created much faster than they can be debunked

Longer answer is that it takes a few seconds for a kid with a blog to make a rumour that gets picked up, linked, tweeted, copied, retweeted etc until it has saturated the web. It takes potentially hours to days to properly research the topic to debunk (especially if the topic is complicated and needs to be explained for a layman audience).

It doesn't surprise me that NASA doesn't have a dedicated team of debunkers, it would be a colossal waste of time and money (caveat being for specific newsworthy/political myths). In the time it would take them to debunk myth A myths B, C, D, E, F, G...Z have been made and are shooting around the blogosphere.

 

[Drakkith]

Also on this coming Dec 21st, lakhs of people are going to gather in this temple to take a holy dip in a pond, as on that day the Saturn is believed to be shifting from one zodiac into another zodiac.Certainly the above internet story may get a new lease of life and do another round with more myths with the unsolicited blessing of none other than NASA!

Are we talking about the planet Saturn? It will be in Virgo for another year or two at least I believe. And whether or not this myth gets perpetuated has nothing to do with NASA.