Moons That Escape Their Planets Could Become 'Ploonets' (sciencenews.org) 78
Meet ploonets: planets of moonish origin. In other star systems, some moons could escape their planets and start orbiting their stars instead, new simulations suggest. Scientists have dubbed such liberated worlds "ploonets," and say that current telescopes may be able to find the wayward objects. From a report: Astronomers think that exomoons -- moons orbiting planets that orbit stars other than the sun -- should be common, but efforts to find them have turned up empty so far. Astrophysicist Mario Sucerquia of the University of Antioquia in MedellÃn, Colombia and colleagues simulated what would happen to those moons if they orbited hot Jupiters, gas giants that lie scorchingly close to their stars. Many astronomers think that hot Jupiters weren't born so close, but instead migrated toward their star from a more distant orbit.
As the gas giant migrates, the combined gravitational forces of the planet and the star would inject extra energy into the moon's orbit, pushing the moon farther and farther from its planet until eventually it escapes, the researchers report June 29 [PDF] at arXiv.org. "This process should happen in every planetary system composed of a giant planet in a very close-in orbit," Sucerquia says. "So ploonets should be very frequent." Some ploonets may be indistinguishable from ordinary planets. Others, whose orbits keep them close to their planet, could reveal their presence by changing the timing of when their neighbor planet crosses, or transits, in front of the star.
As the gas giant migrates, the combined gravitational forces of the planet and the star would inject extra energy into the moon's orbit, pushing the moon farther and farther from its planet until eventually it escapes, the researchers report June 29 [PDF] at arXiv.org. "This process should happen in every planetary system composed of a giant planet in a very close-in orbit," Sucerquia says. "So ploonets should be very frequent." Some ploonets may be indistinguishable from ordinary planets. Others, whose orbits keep them close to their planet, could reveal their presence by changing the timing of when their neighbor planet crosses, or transits, in front of the star.
Huh (Score:1)
A lot of masses that are now planets may have, at some point in time, been moons. There may be no way to distinguish between a planet now versus a previous moon a billion+ years ago. So calling it a ploonet is just syntactic sugar.
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It's more than that. If we add ploonets, then the first person(s) to come up with that obvious portmanteau can feel special about themselves. For science!
I've been to Scotland. They've told me about ploonets years ago.
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Are you saying that they pronounce "planets" as "ploonets" in Scotland?
Because, um, they don't...
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Are you saying that they pronounce "planets" as "ploonets" in Scotland? Because, um, they don't...
I'll bet you're a lot of fun at parties.
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- A satellite of a star? ... Planet!
So you are saying Ceres and all of the other asteroids in the asteroid belt are planets?
That's simpler I guess but damn if I'll be able to remember the 1.9 million word mnemonic for all the planet names at that point...
"My Very Excellent Mother Created Vigorous Portions Heaping Elements Defined Slightly... [solarstory.net]
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Based upon complexity Pluto is and Mercury is not.
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No, he's saying they're planetoids.
He wrote his logic tree in the wrong order. The more specific cases need to come first, so people can just run through it top down and choose the first fit.
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And the ISS is a moon, along with thousands of other artificial satellites. Or perhaps a communication satellite is more of a moonoidoidoidoid.
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I think it's safe to classify ISS and other human built, orbiting objects as "satellites". instead.
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A lot of masses that are now planets may have, at some point in time, been moons. There may be no way to distinguish between a planet now versus a previous moon a billion+ years ago. So calling it a ploonet is just syntactic sugar.
I agree, a ploonet is just a planet; giving it a different name is just silly and doesn't add anything to science or really help in clarifying when discussing an object. Because we can't always know if an object originated as a moon or not, the invention of the word "ploonet" is probably imprecise, and confusing, and totally unnecessary.
This is astrophysics not sociology; there shouldn't be a need to invent words just to try and pretend you're a real science; it is a real science.
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> Because we can't always know if an object originated as a moon or not,
Unless we observe it or deduce it. Not all ploonets left their hosts from a previously unknowable state.
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A lot of masses that are now planets may have, at some point in time, been moons.
If the orbit is nearly circular, and isnt shared, then there is: It wasnt a moon.
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Be thankful they didn't call them "mlanets".
Reason you cannot find them (Score:4, Informative)
Anything named "ploonet" will automatically throw itself into the sun to burn away the shame.
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Anything named "ploonet" will automatically throw itself into the sun to burn away the shame.
If only the inventor of the word "ploonet" would do the same.
That’s no moon... (Score:2)
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... it’s a spooce station.
Is it only a spooce station if it leaves a ploonet's orbit and starts circling the sun instead?
What about if a ploonet has rings? Are they roongs?
Poor Pluto (Score:2)
If they started as moons, wouldn't moonlet be better?
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Understated (Score:2)
In other star systems, some moons could escape their planets and start orbiting their stars instead, new simulations suggest.
Also in this star system. Was that deemed too scary for the unwashed masses to hear? How about this: it has almost certainly already happened here. One of the gas giants in the solar system could have lost a moon sometime after humans started talking and we'd never know.
Jupiter is too big to allow permanent stability anywhere in the system. That and we call rocks as tiny as Phobos and Deimos moons. One not very big impactor and Mars could lose either one quite easily. No we don't have a simulation of
This is incredibly pointless (Score:5, Insightful)
Beyond the footnote fact of a planet once being a moon does the distinction actually bare any significance? I feel like astronomy is getting a little too anal about the classification of bodies. So a planet is a body orbiting a star that is large enough to have cleared its orbit. A moon is a body that orbits a planet. A dwarf planet is like a planet but has failed to clear its orbit. All planets had shit in their orbit at some point and eventually cleared them, whats the time cutoff? At what point do we decide its out of time and now a dwarf planet? Apparently to minimally qualify for either planet or dwarf planet you have to also be massive enough to reach hydrostatic equilibrium. Below that and you are either an asteroid or comet depending on what you are made out of. But moons dont have to be that massive. They can be space potatoes. So what is the practical difference between a ploonet and an asteroid/comet? What about trojan moons which are captured asteroids? If they manage to be free again why dont they just go back to being called asteroids like before?
What is the fucking point? I feel like someone just wanted to get to name something and stroke their own ego.
Re: This is incredibly pointless (Score:1)
Re: This is incredibly pointless (Score:2)
Re: This is incredibly pointless (Score:1)
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So a planet is a body orbiting a star that is large enough to have cleared its orbit.
Planets don't orbit stars, they both orbit a barycenter!!
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> Beyond the footnote fact of a planet once being a moon does the distinction actually bare any significance? I
The orbit is unstable and due to the complexity of moving bodies, partially unknowable, despite knowing the starting condition. I would think this is obvious.
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What is the fucking point?
Science man. For the average Joe you can call everything a planet. No one cares. Also that box that your computer monitor plugs into is the Harddrive and inside it bits move around. Is it necessary to classify this? I heard one day that CPUs execute instructions. Does it bare any significance that part of the instruction is an Opcode and and another an Operand? It is all just bits. What's the point.
The point is that within a field the experts in that field benefit from precise classifications. It ultimately
Proof of Existence? (Score:3)
Slow news day? (Score:2)
What if they become moons again? (Score:1)
Exomoonploonets? Ploopoons? Veronica?
Orbit Deficit Disorder (ODD) (Score:2)
Of course there are moons that leave orbit, travel galactic distances, find new planets to orbit for short amounts of time, and then head back out. The leaving orbit part is probably due to Orbit Deficit Disorder (ODD). The traveling galactic distances and finding other planets to orbit is probably due to Need To Make Multiple Episodes (NOPLOT). All of this results in a 1975 TV show called "Space 1999"
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That Moon was *propelled* by a massive plot device. It wasn't wondering naturally.
Dwarf Planet (Score:1)
And The Left Wonders Why... (Score:2)
And the left wonders why so many people are "anti science". When "scientists" do stupid shit like making up "ploonets", people criticizing them for being absolutely retarded are not "anti science". The "scientists" and the morons that believe in them religiously, are the ones who are anti science.
Venus (Score:2)
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The idea of "captured" moons also makes little sense unless you introduce a 3rd body that is no longer present, but people keep thinking these crazy anti-conservation-of-energy ideas.
Disrespect (Score:2)
As far back (at least) as Space: 1999 the term was "rogue moon", which is way more bad-ass.
This term was never used in Space: 1999 (Score:2)
So I question its validity.
inner planets (Score:2)
Could Mercury have been a moon of a since deceased hot Jupiter of the Sun? Or the other rocky planets, for that matter. If hot Jupiters originate further out and migrate in towards the star, can they eventually lose enough angular momentum to migrate all the way into the star? Leaving their escaped moons behind, to become planets (I can't bring myself to say "ploo...").
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This seems unlikely. I'd expect their orbits to be far more eccentric if they were rogue moons.