Kepler Telescope Glimpses Population of Free-Floating Planets (phys.org) 44
Tantalizing evidence has been uncovered for a mysterious population of "free-floating" planets, planets that may be alone in deep space, unbound to any host star. The results include four new discoveries that are consistent with planets of similar masses to Earth, published today in Monthly Notices of the Royal Astronomical Society. Phys.Org reports: The study, led by Iain McDonald of the University of Manchester, UK, (now based at the Open University, UK) used data obtained in 2016 during the K2 mission phase of NASA's Kepler Space Telescope. During this two-month campaign, Kepler monitored a crowded field of millions of stars near the center of our Galaxy every 30 minutes in order to find rare gravitational microlensing events. The study team found 27 short-duration candidate microlensing signals that varied over timescales of between an hour and 10 days. Many of these had been previously seen in data obtained simultaneously from the ground. However, the four shortest events are new discoveries that are consistent with planets of similar masses to Earth. These new events do not show an accompanying longer signal that might be expected from a host star, suggesting that these new events may be free-floating planets. Such planets may perhaps have originally formed around a host star before being ejected by the gravitational tug of other, heavier planets in the system. Confirming the existence and nature of free-floating planets will be a major focus for upcoming missions such as the NASA Nancy Grace Roman Space Telescope, and possibly the ESA Euclid mission, both of which will be optimized to look for microlensing signals.
Missing mass? (Score:3, Interesting)
Perhaps these could account for some of the missing mass of the universe that has led to the speculative dark matter theory?
Re:Missing mass? (Score:4, Insightful)
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Thats why I said "some". However you have enough "somes" - cold interstellar gas, planets, etc then you eventually get a whole.
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Thats why I said "some". However you have enough "somes" - cold interstellar gas, planets, etc then you eventually get a whole.
Still no.
One of (several reasons): Such "somes" all end up having a non-trivial temperature due to interacting with electromagnetic radiation. That would make them show up in infrared surveys. This is not happening. Hence, such "somes" do not exist in sufficient amounts to account for even a tiny portion of what would be needed.
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Neutrinos wouldn't show up because they don't have a temperature.
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That only applies if said particles can interact with matter and transfer energy. Neutrinos very rarely do and when they do they impart little energy anyway so if they had any temperature it would be close to absolute zero. Back to school for you.
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In your original comment, you're talking about the missing mass that led to the current thinking about dark matter, and that's what my comment addressed. Ideas of free-floating planets is a drop in that bucket and would have negligible influence on the effects that were crucial to ideas of dark matter.
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Being flippant doesn't add anything to your argument. And sure, planets wouldn't do it, but something like small free floating neutron stars might add a lot more mass.
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One that isn't surrounded by a cloud of gas or other matter emitting EM that can be seen obviously.
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Why not? Space is _big_, and free floating planets in intergalactic space would be undetectable except by their mass affecting the Hubble constant and the overall expansion of the universe, just like "dark matter". They'd also be _cold_, though how cold is a good line of research and analysis.
When you don't know how many of something exist, especially something that is very difficult to detect at all, it's poor logic to assume in advance how many there are.
Re:Missing mass? (Score:5, Insightful)
We know how much faster galaxies are rotating than they should be according to tested theories about mass. We know how much gravitational lensing there should be according to those theories. We know how big the clumps in the cosmic background should be. We know how much extra mass is needed to produce what we actually see.
It's not logical to ignore known facts, and it's not logical to ignore what those facts tell us about lower bounds and upper bounds.
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We also know with absolute certainty that there is no significant quantity of this dark matter anywhere inside our solar system or anywhere in it's vicinity.
Basically all the mass needed to account for all the motions of the planets using General Relativity to within observational error is there is ordinary visible mass.
So either there is something "special" about our corner of the Milk Way or well....
Meanwhile I am tired of hearing that using Newtonian mechanics to simulate galactic rotation doesn't work.
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We know many ways in which planets can form and how they migrate.
Not really. We have simulations created post-facto the formation of planets that show us some ways that it could've happened, assuming all of the simulation parameters are accurate. None of those actually proves anything.
We know that, in our own solar system, all known planets, dwarf planets, asteroids, comets, can comfortably fit inside the sun with plenty of mass to spare.
The free mass around a star has been mostly absorbed into the star. What a revelation! /s
Too bad it doesn't tell us anything about interstellar space.
We know how much faster galaxies are rotating than they should be according to tested theories about mass. We know how much gravitational lensing there should be according to those theories. We know how big the clumps in the cosmic background should be. We know how much extra mass is needed to produce what we actually see.
Therefore the extra mass is a previously unknown form of matter whose properties make them impossible to directly detect and don't interact w
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Not really.
Yes really. I did NOT say "we know ALL ways". I said "we know MANY ways". Simulations are run with many parameters that are proposed/added/removed and tweaked none of them would fling so much matter out into interstellar space that would make a significant chunk of dark matter observations.
None of those actually proves anything.
So we can make up whatever shit we want!
The free mass around a star has been mostly absorbed into the star. What a revelation! /s
No, you idiot. The point is that the star is BY FAR the most dominant mass in its vicinity and no amount of ejected planetary material can account for dark matter observations to an
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> No, you idiot. The point is that the star is BY FAR the most dominant mass in its vicinity and no amount of ejected planetary material can account for dark matter observations to any significance.
Inside the solar system itself, you're likely correct. However, interstellar and intergalactic space are _large_, far larger than the solar system. Even for the most extreme edges of our solar system, the next star is roughly 3 times that distance. But that's the nearest star: in the 3D void that is most of ou
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No, very unlikely. The missing mass is far too much to be accountable using rogue planets , primordial blackholes, or anything like that. Its an incredibly large mass.
Re:Missing mass? (Score:4, Informative)
Re: Missing mass? (Score:1)
missing mass of the universe that has led to the speculative dark matter theory?
The "missing mass" *is* the dark matter theory, numbnuts. The "dark" in "dark matter" just means "missing" in exactly the sense you are using it.
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Almost certainly not. There simply isn't enough baryonic matter in the universe to account for observations. These probably wouldn't adjust that number up even a measurable fraction.
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"Perhaps these could account for some of the missing mass of the universe that has led to the speculative dark matter theory?"
Naw, that's just the Pierson's Puppeteers, fleeing with their planets from the exploding black hole in the center of the Milky Way.
Melancholia (Score:1)
I can't wait, I've fantasized about it my entire life, I can't think of a better outcome for humanity.
https://media0.giphy.com/media... [giphy.com]
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You want us to go around obliterating other planets with ours? That's cruel, but it would look really sweet!
Free-Floating (Score:4, Funny)
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Puppeteers fleeing from the galactic core explosion, most likely.
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Fleet of Worlds (Score:1)
Should not be a surprise (Score:2)
I read somewhere that the forming of our own planets was believed to be the result of another star passing the sun nearby and dragging a cloud of matter out of it. The passing star would be gone too quickly for the matter to follow it, so the matter remained in orbit around the sun and then clogged together to form our planets.
If that is how planets are formed, it would not be a surprise if some of that mass could escape the mother star's gravitational influence.
Or, if a passing star can extract matter from
just think (Score:2)
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"A dent"? How big is your spaceship exactly?
Is that a rocket in your pocket because I am ready to blast off!
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Free floating planets are some of the best candidates for being space ships.
If you have enough of an energy source in your planet you can use it to provide the heat (etc.) that you need for whatever kind of life you have around to function. So if you can break a planet loose from a star system it could be quite useful as a generational ship.
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it could be quite useful as a generational ship.
Is that before or after the planet freezes?
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If you have enough of an energy source in your planet you can use it to provide the heat (etc.) that you need for whatever kind of life you have around to function. So if you can break a planet loose from a star system it could be quite useful as a generational ship.
Is that before or after the planet freezes?
Learn to read, noob.
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> Free floating planets are some of the best candidates for being space ships.
That's no moon, it's a space station!
https://xkcd.com/307/ [xkcd.com]
Dalek Invasion of Earth (Score:2)
This proves Doctor Who is real. Daleks have kidnapped these planets and are using them as spaceships to conquer the universe. Or maybe Fred Hoye's ideas from The Black Cloud or Fifth Planet.
Rogue planets are interesting. Under the current IAU rules, they're all classed as Brown Dwarfs, even the rocky planets, as they are not orbiting a star. Which is a problem.
On the other hand, it would be intriguing to know conditions on such planets. Pluto and Europa have liquid water under the ice, proving a lack of sol
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Heading in which direction? (Score:2)
Wanderers (Score:2)
Since the word 'planet' comes from the Greek word for 'wanderer', these are the most planety of planets.