Fifth moon found around Pluto!:

http://phys.org/news/2012-07-hubble-space-telescope-moon-pluto.html

Originally posted by sonhouse
http://phys.org/news/2012-07-hubble-space-telescope-moon-pluto.html

I do wonder how many of these are proper moons, and how many are pseudo-moons. It does make a difference when considering the question of the origin of Pluto (or even the solar system as a whole).

Richard

Originally posted by Shallow Blue
I do wonder how many of these are proper moons, and how many are pseudo-moons. It does make a difference when considering the question of the origin of Pluto (or even the solar system as a whole).

Richard

-sorry, mispost. Anyone; how does one delete a post made by accident? I haven't worked that out yet.

Originally posted by Shallow Blue
I do wonder how many of these are proper moons, and how many are pseudo-moons. It does make a difference when considering the question of the origin of Pluto (or even the solar system as a whole).

Richard

What do you mean by pseudo moon? If it a pile of rock a mile or two in diameter, couple of Km, it is a pretty big rock, the size of a respectable mountain. What do you mean by pseudo? Humy, I think you have to ask a mod to remove a post. Don't quote me on that however

Originally posted by Shallow Blue
I do wonder how many of these are proper moons, and how many are pseudo-moons. It does make a difference when considering the question of the origin of Pluto (or even the solar system as a whole).

Richard

As with the term "planet," I think a more rigorous definition for what constitutes a "moon" is in order. Once we get down to the size of a double-wide trailer it's not a moon.

Originally posted by humy
-sorry, mispost. Anyone; how does one delete a post made by accident? I haven't worked that out yet.

Edit the post by inserting an F-bomb. The nanny-filter will delete it forthwith.

Originally posted by Soothfast
As with the term "planet," I think a more rigorous definition for what constitutes a "moon" is in order. Once we get down to the size of a double-wide trailer it's not a moon.

The ones they just discovered are miles across so we haven't hit SUV size yet

Originally posted by Soothfast
Edit the post by inserting an F-bomb. The nanny-filter will delete it forthwith.

I just tested that with my post here.
I first posted "you mean " without the F-bomb to simulate an accidental post and then tried to re-edit it just by appending the f-bomb to that and the nanny-filter deleted the re-edited version but not the original which stayed put so unfortunately that wouldn't have worked. Nice try though.

Originally posted by sonhouse
What do you mean by pseudo moon? If it a pile of rock a mile or two in diameter, couple of Km, it is a pretty big rock, the size of a respectable mountain. What do you mean by pseudo? Humy, I think you have to ask a mod to remove a post. Don't quote me on that however

Not sure but I think he means a rock or object that is mistakenly assumed to be orbiting a planet because it is seen very close to it but is in fact orbiting the sun or just passing the planet by and is not in a stable orbit around the planet.

Originally posted by humy
I just tested that with my post here.
I first posted "you mean " without the F-bomb to simulate an accidental post and then tried to re-edit it just by appending the f-bomb to that and the nanny-filter deleted the re-edited version but not the original which stayed put so unfortunately that wouldn't have worked. Nice try though.

Ah. I now seem to recall that in the early days I had to repeat the process two or three times before the filter simply deleted the post for good, but then there came a point when just one go would turn the trick forever after. It works for me. I've done it dozens of times. But I guess you have to piss the nanny off first.

If you still have no success I shall submit another theory.

The post that was quoted here has been removed

This is just a test.

Okay, so, I had a third post inserted between the two above, which I had quoted in the post below it. I F-bombed it, and it's gone. The nanny knows I'm a naughty boy.

Originally posted by Soothfast
As with the term "planet," I think a more rigorous definition for what constitutes a "moon" is in order. Once we get down to the size of a double-wide trailer it's not a moon.

There is one already. I don't know the details, or even the official terms; I just know that the distinction is made by real astronomers who understand these matters better than I.
However, AIUI a proper moon is a body orbiting anothing body which was formed from that larger body, or from the same accretion disc (as our moon is believed to be, and I think Charon as well, for Pluto). A pseudo-moon is any heap of rock which happens to circle any (dwarf?) planet. The Earth has a number of these as well, all of them small (smallish, anyway). Obviously, this distinction would be important if Pluto's moons are to be used to draw conclusions about Pluto's origin.

Richard

Originally posted by Shallow Blue
There is one already. I don't know the details, or even the official terms; I just know that the distinction is made by real astronomers who understand these matters better than I.
However, AIUI a proper moon is a body orbiting anothing body which was formed from that larger body, or from the same accretion disc (as our moon is believed to be, and I th ...[text shortened]... mportant if Pluto's moons are to be used to draw conclusions about Pluto's origin.

Richard

Where are you getting this? Astronomy sites I've gone to say (if they say anything at all) only that there is no "hard" definition. The definition you give is reasonable, but try to find the astronomy textbook that says Mars has no moons, or that Jupiter has only four moons.

Originally posted by Soothfast
Where are you getting this? Astronomy sites I've gone to say (if they say anything at all) only that there is no "hard" definition. The definition you give is reasonable, but try to find the astronomy textbook that says Mars has no moons, or that Jupiter has only four moons.

I got this idea from a (popularising but not braindead) television program on astronomy, but to be honest I can't recall which one.

In any case, however they want to call it, the distinction would be relevant in this case.

Richard