2 New Moons of Pluto Found

[mmarable]

Get a load of this.

http://www.space.com/scienceastronomy/0 ... moons.html

[Malenfant]

I sure didn't expect that!!

[Dollan]

I am absolutely amazed. I suppose that I should have suspected that something like this was possible after the discovery of an asteroid with two moons. But still....

It is often claimed that two moons orbiting a planet such as Earth would be dynamically unstable, and that the single moon-Earth system was the only possible outcome, setting aside for the moment the possibility of *no* moon forming after that great ruddy impact. But now...

...John...

[symaski62]

The moons are catalogued as S/2005 P1 and S/2005 P2 for now. Once they are confirmed, the discoverers will suggest names, to be approved by the International Astronomical Union.

THAT !!!!

[Dollan]

I know that it is premature, but still... does it seem like these two new little guys are sharing the same orbital distance?

...John...

[Malenfant]

It is often claimed that two moons orbiting a planet such as Earth would be dynamically unstable, and that the single moon-Earth system was the only possible outcome, setting aside for the moment the possibility of *no* moon forming after that great ruddy impact. But now...

...John...

I've never heard that two moons orbiting the Earth would necessarily be unstable - the problem would be Earth's proximity to the Sun, and the solar tides might disrupt the system eventually.

In Pluto's case there's no solar tides to worry about .What is curious is that Pluto and Charon are completely tidally despun relative to eachother, yet apparently there's two moons now - I'm guessing that if they're really there then they aren't massive enough and are too far away to significantly affect the tidal interactions between Pluto and Charon that caused them to lock relative to eachother.

[granthutchison]

I know that it is premature, but still... does it seem like these two new little guys are sharing the same orbital distance?

Not according to IAU circular 8625, or the discoverers' site at http://www.boulder.swri.edu/plutonews/ (they're using Celestia to plot the orbits!)
I dropped by to say I've just sent Selden an update version of poormoons.ssc including these objects with their estimated semimajor axes and radii, but no mean anomalies - these don't seem to have been released and it's too much of a faff to adjust the positions by hand to match the discovery images.
It'll take a while for even Selden's lightning responses to put the new file up, so meanwhile here are the definitions:

Code: Select all

"2005P1" "Sol/Pluto" # (IAUC 8625)
{
   Texture       "asteroid.jpg"
   Mesh      "asteroid.cms"
   Radius      70 # ~140 km diameter for 15% albedo
   
   InfoURL "http://www.boulder.swri.edu/plutonews/"

   EllipticalOrbit
   {
   Period      38.2
   SemiMajorAxis   64700
   AscendingNode   273  # "probably in the same plane as Charon"
   }

   Albedo 0.15 # estimate, based on KBOs
}

"2005P2" "Sol/Pluto" # (IAUC 8625)
{
   Texture       "asteroid.jpg"
   Mesh      "asteroid.cms"
   Radius      60 # ~120 km diameter for 15% albedo
   
   InfoURL "http://www.boulder.swri.edu/plutonews/"

   EllipticalOrbit
   {
   Period      25.5
   SemiMajorAxis   49400
   AscendingNode   273  # "probably in the same plane as Charon"
   }

   Albedo 0.15 # estimate, based on KBOs
}

Grant

[t00fri]

Not according to IAU circular 8625, or the discoverers' site at http://www.boulder.swri.edu/plutonews/ (they're using Celestia to plot the orbits!)

I could not find Celestia acknowledged anywhere, despite a detailed Acknowledgement at the end of the site.

Anybody else saw a reference?

Bye Fridger

[Dollan]

No acknowledgment, no.

Do they need to, though? Certainly it would be nice; not everyone is going to recognize the program that generated the first image on their page.

...John...

[t00fri]

These guys are supposed to be scientists. Right? In science it is considered extremely bad style, NOT to acknowledge work by others that has been used. Be it another scientific paper or a computer program used during the analysis etc.
Citing correctly in the course of scientific work is a basic necessity that cannot be overestimated. We badly need integrity in this domain, otherwise also here the respective community is up for moralic decline...Next time one goes on and steels somebodys little idea without mention...

Nobody would care about the juristical situation. It's just BADLY against the codex ...

Bye Fridger

[Dollan]

Alright, alright. Calm yourself! I was just asking.

I am curious, though, does this extend to using such programs as, say, MS Office? Where is the line between using a tool and using a resource?

Note, I'm not challenging anything. I am simply curious....

...John...

[Malenfant]

These guys are supposed to be scientists. Right? In science it is considered extremely bad style, NOT to acknowledge work by others that has been used. Be it another scientific paper or a computer program used during the analysis etc.

Another paper? Sure.
A data source? Definitely.
Referees? People you had discussions with? Absolutely.
Somone who writes a program for you? Certainly

A publicly available program is totally different though. You don't see papers written with acknowledgements of "The author would like to thank to Adobe for Acrobat 6, Microsoft for Word, and Maplesoft for Maple used in this paper" after all.

Had the people on that website used an ssc that someone else wrote for them then darn straight they should credit the people who wrote it. But I really don't see a requirement for scientists to credit a program that they added something to for visualisation purposes.

Next time one goes on and steels somebodys little idea without mention...

You say this as if it doesn't happen in science at all all! Ideally it shouldn't, bu tin practice sadly it does happen quite a lot - particularly when unscrupulous supervisors claim their students results as if it was their own work. I've seen this happen myself a couple of times.

[t00fri]

These guys are supposed to be scientists. Right? In science it is considered extremely bad style, NOT to acknowledge work by others that has been used. Be it another scientific paper or a computer program used during the analysis etc.

Another paper? Sure.
A data source? Definitely.
Referees? People you had discussions with? Absolutely.
Somone who writes a program for you? Certainly

A publicly available program is totally different though. You don't see papers written with acknowledgements of "The author would like to thank to Adobe for Acrobat 6, Microsoft for Word, and Maplesoft for Maple used in this paper" after all.

Had the people on that website used an ssc that someone else wrote for them then darn straight they should credit the people who wrote it. But I really don't see a requirement for scientists to credit a program that they added something to for visualisation purposes.

Next time one goes on and steels somebodys little idea without mention...

You say this as if it doesn't happen in science at all all! Ideally it shouldn't, bu tin practice sadly it does happen quite a lot - particularly when unscrupulous supervisors claim their students results as if it was their own work. I've seen this happen myself a couple of times.

You are overlooking a big difference: By paying hundreds and thousands of Dollars for Adobe's Acrobat 6, for MS Word, and Maplesofts Maple, you have bought yourself the right to use those programs without further mention. By contract with those commercial firms.

Also scientists write a lot of programs that will be used by other scientists worldwide. All free of charge, of course, quite unlike Adobe's Acrobat 6, MS Word, and Maplesofts Maple...

It is quite unthinkable NOT to cite such program packages in any scientific documentation or paper. I think Celestia is indeed close to satisfying precisely these standards, otherwise Celestia wouldn't be used by scientists, by NASA etc.

You say this as if it doesn't happen in science at all all! Ideally it shouldn't, bu tin practice sadly it does happen quite a lot - particularly when unscrupulous supervisors claim their students results as if it was their own work. I've seen this happen myself a couple of times.

Yes there are always bad exceptions, that's why I feel very strongly about a pertaining a solid "culture" of citation. But from my ample and longstanding experience at one of the world-leading labs in particle physics, such things you mention are getting increasingly rare the higher the reputation of the respective institution. Excellent graduate students are actually much less "helpless" as it might look at first sight.

Bye Fridger

[Malenfant]

Also scientists write a lot of programs that will be used by other scientists worldwide. All free of charge, of course, quit unlike Adobe's Acrobat 6, MS Word, and Maplesofts Maple...

Usually the programs you mention that scientists write aren't open source projects though.

Celestia certainly isn't a program written by scientists either. Scientists have had input into it, definitely. But it is not specifically a tool like a modelling program for example.

And also, a webpage certainly is not a peer-reviewed paper. Perhaps if Celestia was used in such a publication then you'd be more justified in complaining that they hadn't credited it, but this is just an informal webpage.

It is quite unthinkable NOT to cite such program packages in any scientific documentation or paper. I think Celestia is indeed close to satisfying precisely these standards, otherwise Celestia wouldn't be used by scientists, by NASA etc.

It would be nice to credit it, I'm not disagreeing with that. I just don't agree that it is a requirement to do so on something as informal as a webpage.

The important thing here is that two more moons of pluto have been discovered - not that they used Celestia to display a picture of their orbits.

[t00fri]

Also scientists write a lot of programs that will be used by other scientists worldwide. All free of charge, of course, quit unlike Adobe's Acrobat 6, MS Word, and Maplesofts Maple...

Usually the programs you mention that scientists write aren't open source projects though.

I guess I should know that. For various good reasons

One being that I have written plenty of scientific open source code myself. Actually every little detail of research (including all resources used) has to be made public by the constitution of most research labs. All computer code MUST be open source. Go to any big lab site, you can download ALL their generated code. Or you email to the authors...
Why don't you simply believe me. I DO know that. I certainly can provide the pointers on demand

Celestia certainly isn't a program written by scientists either.

Chris has a bachelor in math & physics, I am definitely a scientist (and a co-author of Celestia), Grant is a (medical) scientist (and co-author) , quite a number of other Celestia developers/co-authors have studied physics or computer science.

So what exactly did you mean here?

Scientists have had input into it, definitely. But it is not specifically a tool like a modelling program for example.

Celestia is /precisely/ a modelling program: it models the UNIVERSE...

It would be nice to credit it, I'm not disagreeing with that. I just don't agree that it is a requirement to do so on something as informal as a webpage.

We are not talking about requirements in the juristical sense. Nobody puts me into jail if I start tomorrow with not quoting the papers of fellow scientists of mine in my work...but I would loose my reputation in a VERY short time. It's against the "spirit" in any scientific community.

Bye Fridger

[PlutonianEmpire]

Pluto with three moons, huh?

I can't wait to see the view from the planet's terraformed sky....

[Don. Edwards]

Well this was an issue almost 2 years ago. NASA had pictures on there site showing Mars data and they were using Celestia at that time and never acknowledged what they were using for the rendering of there graphics. So they are just doing it again. We can't force them to give credit were credit is due, just the same as I haven't included the included the supposed required info with my textures as to the NASA data in them. I plan on changing that but NASA, since they started using Celestia 3 years ago has treated Celestia as there own toy, to do with as they like as far as I am concerned.
Just me 2 cents.

Don.

[Malenfant]

Well this was an issue almost 2 years ago. NASA had pictures on there site showing Mars data and they were using Celestia at that time and never acknowledged what they were using for the rendering of there graphics. So they are just doing it again. We can't force them to give credit were credit is due, just the same as I haven't included the included the supposed required info with my textures as to the NASA data in them. I plan on changing that but NASA, since they started using Celestia 3 years ago has treated Celestia as there own toy, to do with as they like as far as I am concerned.
Just me 2 cents.

Don.

Well, perhaps they're using their own modified version of Celestia (not unlikely since the code is open source) and therefore feel they don't need to give credit to anyone else?

And even if they aren't, all I've seen here is people throwing accusations and getting all indignant about something they have no information on. Has anyone even bothered to politely ask the people at the pluto website with the "offending image" on it if they could add a credit to Celestia in the acknowledgements of their website? Or is everyone here just jumping to conclusions?

[Malenfant]

Celestia certainly isn't a program written by scientists either.

Chris has a bachelor in math & physics, I am definitely a scientist (and a co-author of Celestia), Grant is a (medical) scientist (and co-author) , quite a number of other Celestia developers/co-authors have studied physics or computer science.

So what exactly did you mean here?

I meant that with the exception of a few people (yourself being one) most of the people who wrote Celestia are not professional scientists (let alone professional astronomers).

Celestia is /precisely/ a modelling program: it models the UNIVERSE...

I meant in the sense of numerical modelling. It's not a finite-element modelling program written by a scientist for calculating crustal stress for one of his publications, for example.

Besides which, for all that scientists are supposed to release the code that they write, it's often damn hard to get hold of it - for starters the code itself is often published in rather obscure journals. And even if you get in touch with the scientists directly there's no guarantee they'd be willing to let you use their code. They can often be very protective/possessive of their program, often to the point of not letting people have the code if they don't like the sound of what they're going to do with it, or even insisting on a co-authoring credit just for allowing people to use the program when they don't do anything to write the paper itself. And they're often generally not keen on people altering it either. The scientific community - or at least parts of it - has a long awy to go if it is to become truly 'open source' in practice in the sense that the Celestia or other programming communities are.

Maybe your experience differs from what I've seen and experienced. Ideally scientists should exchange their ideas and programs openly and freely, but in practise I find that most of the time politics and personal rivalries get in the way of that ideal.

We are not talking about requirements in the juristical sense. Nobody puts me into jail if I start tomorrow with not quoting the papers of fellow scientists of mine in my work...but I would loose my reputation in a VERY short time. It's against the "spirit" in any scientific community.

Again, there are far worse crimes that go on all the time in the scientific community that go very much against the "spirit of the scientific community". Railing against what could just be a minor oversight on a public website like this seems like an over-reaction to me. This is not someone claiming credit in a peer-reviewed paper for work that someone else did - it is not remotely similar.

And besides, if it bothers you that much why don't you write the people at that website a polite email asking them if they would be so kind as to add a credit to Celestia to their webpage? Complaining about it here won't accomplish anything.

[AlexChan]

Hello, I come from Hong Kong.
And I read this news in NASA.com last night before sleep.

I just have a question..
That 2 moons are irregular body?