'Homeless' Planets May Be Common In Our Galaxy

sciencehabit writes "Our galaxy could be teeming with 'homeless' planets, wandering the cosmos far from the solar systems of their birth, astronomers have found. In a paper published online today in Nature, the researchers list 10 objects in our galaxy that are very likely to be free-floating planets. What's more, they claim that in our galaxy, free-floaters are probably so populous that they outnumber stars."

Comments

Wonder

[Dyinobal]

I wonder if any are space ships.

Re:Wonder

[Anonymous Coward]

Marsoid Hologram: "We worked ourselves to extinction turning out planet into a navigable space-ship"
Zim: "why?"
Hologram: "Because it's really cool!"

Re:Wonder

[elrous0]

No. It's lonely out in space.

Re:Wonder

[Bengie]

OMG! it's a Death Star!

Sorry, had to.. :*(

Re:Wonder

[LWATCDR]

That is no moon!
Wow talk about just not a good idea. I do not think I want to find a civilization that can build planet sized space craft. Hey at least they are slow. Maybe they are Outsiders?

Dark matter?

[gstoddart]

OK, so I've never really understood 'dark matter', but if there's a bunch of stuff floating about that's not stars and only shows up through things like gravitational micro-lensing ... might this cover some of the mass that is dark matter?

Or is this just way to insignificant to account for it?

A bunch of planets floating around in space without orbiting a star is probably a lot -- but maybe nowhere near enough to account for whatever bits of whatever equations that leads us to ponder dark matter.

Re:Dark matter?

[Anonymous Coward]

LOL WUT

Re:Dark matter?

[Covalent]

I thought the same thing...if the planets outnumber stars, but tend to be smaller than stars, then perhaps the mass of them is roughly equal. Not enough to account for all of the "missing mass", but certainly enough to affect the hypotheses regarding its quantity and properties.

Re:Dark matter?

[shish]

A bunch of planets floating around in space without orbiting a star

Come to think of it, why are we working on the assumption that basically every object in the universe is on fire*? As a personal bet, £5 says that the vast majority of mass in the universe is in solar systems where the central object either wasn't on fire, or has burnt out billions of years ago

* Yeah, AFAIK the official explanation for this assumption is "because that's all we can see", but maths says there must be more - the explanation for the rest always seems to have dark matter being some mysterious meta-mass unlike anything we know about, rather than simply being planets with no nearby light source...

Re:Dark matter?

[EasyTarget]

I have seen articles on DM talk about how intersolar and intergalactic dust clouds have been accounted for but I dont know 'how'.

It may be that these bodies get accounted for in our current models since they will have a similar effect when observed at a distance; blocking light, affecting gravitational interactions and emitting radiation. So maybe these are already captured in the models and what we are seeing here is a refinement of what interstellar 'dust' is really composed of..

Re:Dark matter?

[Black Parrot]

A bunch of planets floating around in space without orbiting a star

Come to think of it, why are we working on the assumption that basically every object in the universe is on fire*? As a personal bet, £5 says that the vast majority of mass in the universe is in solar systems where the central object either wasn't on fire, or has burnt out billions of years ago

* Yeah, AFAIK the official explanation for this assumption is "because that's all we can see", but maths says there must be more - the explanation for the rest always seems to have dark matter being some mysterious meta-mass unlike anything we know about, rather than simply being planets with no nearby light source...

And your PHB says it shouldn't take so long to write programs.

How come everyone around here knows more than the experts? Do you really think astronomers are too dumb to think of all the non-stellar matter in and between the galaxies?

Re:Dark matter?

[Anonymous Coward]

If this paper is just being published, I would think that astronomers might be too smart to think of all non-stellar matter when doing their calculations...

Re:Dark matter?

[gstoddart]

How come everyone around here knows more than the experts? Do you really think astronomers are too dumb to think of all the non-stellar matter in and between the galaxies?

Can't speak for the parent ... I don't think astronomers are too dumb to do that, I know that at a minimum, I'm too dumb to fully understand this stuff ... so I asked because if there's suddenly a lot more planets floating about in space, maybe it's mass we've not accounted for.

The problem with astronomy and the like ... is that it is so specialized and arcane, that the rest of us have a hard time understanding WTF they're talking about. :-P

I have no idea what all astronomers have factored into their accounts of non-stellar matter ... have they included the space poop from the space cows? ;-)

Re:Dark matter?

[Delkster]

Apparently it's not very significant since not only are planets smaller than stars, they are smaller by a pretty large factor.

The mass of Jupiter is about 1/1000 solar masses. Let's say the average mass of these independently floating planets is about 10 times that of Jupiter, and that the average star is about the same as our Sun or less. That would make the mass of an average planet about 1/100 of the average star, so you'd still need planets to outnumber stars by a factor of 100 just to equal the mass of stars. Wikipedia says that visible matter makes up for about 17% of the total matter of the universe, so even if the mass of planets equaled that of stars (which, with the very very rough figures above, would mean a planet-to-star ratio of 100, or something pretty large anyway), there would still be plenty of dark matter to explain.

Re:Dark matter?

[gpronger]

I'll take you up on the bet, we just need to figure out how we find ourselves in the same to to even up.

Re:Dark matter?

[MBGMorden]

and that the average star is about the same as our Sun or less.

That's a bad assumption to make (unless by "or less" you're assuming a lot less). The vast majority of the stars in the galaxy (about 85%) are red dwarfs, which are typically 1/5th or less of the mass of the sun.

While our sun is right in the middle of the scale of possible sizes for stars, as far as frequency, it's in the upper 10% of the most massive stars.

Re:Dark matter?

[Chris Mattern]

We know about dark matter not through micro-lensing but because of galactic structure. Galaxies rotate. If all the mass there was in any given galaxy was just what we could see, the centrifugal force would tear apart immediately. The only way we can account for sufficient gravitational attraction to keep stars in their orbits around the galactic center is to assume a lot of mass we can't see--dark matter. Most calculations based on stellar orbits consistently come up with figures for dark matter of over 80% of the matter in the universe. There's more than four times as much dark matter as what we can see. And whatever dark matter is, it apparently is diffuse enough that we don't see it micro-lensing anything, and doesn't otherwise interact with light or other EM radiation, because we find no trace of it in the light that reaches earth from all corners of the universe; therefore it *can't* be ordinary matter as we understand it, because any form of ordinary matter in that quantity would produce detectable occlusion of the light sources behind it. So what is it? Answer that question and win a Nobel.

Re:Dark matter?

[thegreatemu]

There was some attempt a while back to assign dark matter to things like this, or free-floating black holes, brown dwarf stars, etc. I.e., somewhat exotic (or not) objects composed of normal matter.

However, in the past maybe 10 years, the constraints for dark matter come much more from cosmological arguments than from observations of the galaxy today. If you're interested, I'd suggest googling WMAP and baryon acoustic oscillations. The basic idea is that we can study the cosmic microwave background, which is the left over radiation as the universe cooled below a critical point some few 100k years after the big bang. In the CMB are embedded small fluctuations like ripples in a pond after you throw rocks in, which are the imprint of pressure waves spreading outward through the primordial plasma. By studying the size and spacing of these ripples, and applying a whole crapton of cool math, you can deduce things like the speed at which those ripples propagate, which is a direct function of both the total matter density and the baryonic (i.e. normal) matter density.

Of course I'm skipping all the details, but the basic result is that, although we first noticed dark matter from observing the motion of galaxies today, it was confirmed to a much better degree by observing the universe in its birth stages, and it's these latter measurements that tell us that dark matter absolutely cannot be due to the behavior of matter and general relativity as we understand it today.

Re:Dark matter?

[TapeCutter]

The paper is not a new idea, it's evidence for an old idea.

Re:Dark matter?

[radtea]

OK, so I've never really understood 'dark matter', but if there's a bunch of stuff floating about that's not stars and only shows up through things like gravitational micro-lensing ... might this cover some of the mass that is dark matter?

Maybe, for galactic dark matter, which is completely unrelated in every respect to dark matter on larger scales, although ignorant people typically use the general term "dark matter" to refer to all types of dark matter indiscriminately, creating enormous confusion in the process.

Galactic dark matter (GDM) is hypothesized as an explanation for the flat rotation curves of spiral galaxies. Based on the visible matter (stars) in a galaxy we can get an estimate of the mass inside a given radius. At sufficiently high radii we see the amount of visible matter dropping off, and expect that the few stars at even larger radii will start to behave like planets orbiting a distant mass with a 1/r**2 fall off in gravitational strength. But we don't see that. Instead more distant stars move as if the amount of matter inside their orbits around the galactic center contained ever more mass as they get further and further away. We can't see any visible matter to account for this, ergo, "dark matter".

One possible candidate for GDM are so-called "MACroscopic Halo Objects" (MACHOS, to contrast them with Weakly Interacting Massive Particles, or WIMPS. Physicists really need to get out more.)

An impediment to the MACHO hypothesis has been that the Initial Mass Function, which describes the probability of an object of mass M condensing out of a primordial cloud of gas and/or dust, was believed to drop off rather steeply at low masses. This observation suggests that it is at least a little higher than previously estimated, although I don't know if that is anywhere near high enough to account for a significant portion of GDM--my sense is not, but it's been a few years since I've paid much attention to this question.

At larger scales we also see anomalous motion of galaxies and galactic clusters relative to the amount of visible matter, and at the very largest scale there is much less visible mass than required to keep the universe in the state of almost-but-not-quite-closed that we see. If these phenomena are caused by an excess of matter at larger scales we know that it is non-baryonic (not made of protons and neutrons) because we have a very good estimate of the density of protons and neutrons in the universe based on primordial nucleosynthesis: the denser the early universe was in protons and neutrons, the more helium would have been created, and given we know the early universe was about 23% helium (there are complex self-consistency checks on this number based on other atomic species) we know there are not enough protons and neutrons to account for the large-scale dark matter (LSDM).

Therefore, we know that LSDM is completely unrelated in every respect to GDM: the problems they solve have different constraints and one requires exotic new physics while the other is relatively mundane. It is deeply unfortunate that people are so incompetent in their use of abstractions that they are chronically unable to distinguish between these two unrelated problems.

Re:Dark matter?

[Chris Mattern]

I have seen articles on DM talk about how intersolar and intergalactic dust clouds have been accounted for but I dont know 'how'.

Because we can *see* them. They have no light of their own, but they occlude the light sources behind them, changing it even though they may not block it completely. Whatever dark matter is, it is completely transparent to light over intergalactic distances (except for gravitational effects, but apparently it's diffuse enough that those aren't detectable). That's not possible with any form of "ordinary" matter.

Re:Dark matter?

[TapeCutter]

what we are seeing here is a refinement of what interstellar 'dust' is really composed of.

Yep, that's it in a nutshell.

Re:Dark matter?

[gstoddart]

Thanks (to you and the other posters who have actually explained this).

As I suspected, I was talking out of my ass -- nice to have it actually explained. It just seemed that some of this stuff might be "hard to see" (like a planet floating in space), but you're talking about stuff on a completely different scale.

Cheers.

Re:Dark matter?

[Delkster]

You're right, but even if you reduced the mass of the average star to 1/5 in the ballpark calculation, that would still leave a 20:1 mass ratio between the average star and planet. Also, an average of 10 Jupiter masses for a planet is a somewhat generous figure if you compare it to estimated masses of planets known so far, and observational bias probably skews even those figures towards the larger end.

In the end, it might be a small constant factor here or there, and that wouldn't altogether remove the couple of orders of magnitude of difference. Also, not all visible matter is in stars and planets, so the ratio between total mass in planets and total visible mass in the universe would be even lower than the ratio between planets and stars (although I don't know by what kind of a factor), and since the total mass of dark matter is more than the total mass of visible matter, the proportion of dark matter these planets could make up for is again lower.

On the other hand, I guess it might also be that planets are more frequent than we imagine by a large factor.

Re:Dark matter?

[shish]

How come everyone around here knows more than the experts?

Perhaps I phrased badly, but I never meant to imply that I was right, it was more "how do we know that this simple and obvious answer is wrong?"

(I will quite happily put money on things I things I am unsure of if it means someone will give a detailed and interesting explanation of why it's wrong :P)

Re:Dark matter?

[phizix]

This possibility was strongly considered in the 1990s. Such sub-luminal objects were termed MACHOS, as opposed to the other leading theory, where dark matter is composed of WIMP particles which rarely interact with ordinary matter (except gravitationally). The MACHO theories are now strongly disfavored by observations of the cosmic microwave background. The universe didn't produce enough baryons (the particles which give stars, planets, and all ordinary matter most of its mass) to account for all of the dark matter.

Re:Dark matter?

[Anonymous Coward]

So what you're saying is that dark matter is different from black holes because it does not distort light, correct? And the only way with our current understanding of physics for that to happen is to spread out the the immense amount of gravity that needs to be present to keep our galaxy from being torn apart by centripetal (not centrifugal) force, because if the magnitude of gravity in any individual point were too big, light would then be distorted like it is for black holes.

Did I get that right?

Re:Dark matter?

[Anonymous Coward]

Ok, so I actually have an advanced degree in astrophysics. While you do describe the basic observations that lead us to believe dark matter exists, it's not true that galactic dark matter and large scale dark matter are different beasts. True, MAssive Compact Halo Objects (such as rogue black holes, neutron stars, brown dwarfs, etc) (note the correction) were a possible explanation, but we've done observational studies that look for them using microlensing, and although we did find a few, there wasn't nearly enough (i.e. several orders of magnitude less) to explain our galactic rotation curve. WIMPS (such as neutrinos) have been ruled out since they fail to explain the observed large scale galactic structure, and there aren't nearly high enough neutrino counts in neutrino observatories to make them a viable option.
It turns out that, for BOTH galactic rotation curves and large scale darkmatter, you need about 10 times more mass than what we can associate with stars, so the two problems actually do have the same constraints. Therefore, it's very likely that there is some form of matter which only interacts gravitationally (and not electromagnetically: i.e. with light) with normal baryonic matter which has so far been unobserved. (Not surprising, since a lot of our matter detection techniques rely on interactions with light, and besides the required density of this stuff would make it very rare on Solar System scales - it only becomes significant on galactic scale interactions).
On the original article - It's not too surprising that there are lot of free roaming planets, it just indicates that there was a higher degree of fragmentation in molecular clouds than was once thought. However, it would require an insanely HUGE number of them to explain dark matter observations - planets are generally much less massive than stars, somewhere around 10^6 to 10^8 times less massive, so there would have to be 10's of billions times more of them than stars to explain dark matter observations, something that the article does not assert is true.

Re:Dark matter?

[Anonymous Coward]

"Do you really think astronomers are too dumb to think of all the non-stellar matter in and between the galaxies?"

No, but the problem is that astronomers can't (yet) directly detect all the non-stellar matter in and between the galaxies.

They know a fair amount of what -is- there, they can think up a lot of stuff that -could be- there, but until it has been directly observed (by more than only gravitational effect) they aren't going to say it is there, just that - besides the stuff that they do know is there - there's "something" there (which they call Dark Matter exactly because they don't know what it is).

It would not be the first time that some (relatively small) amount of the observed gravitational effect turns out to be caused by something made of normal matter but that has only now been detected because of advancements in detection technology.

Re:Dark matter?

[Anonymous Coward]

It is deeply unfortunate that people are so incompetent in their use of abstractions that they are chronically unable to distinguish between these two unrelated problems.

You had it right in the first sentence. People are ignorant, not incompetent. I've never heard of dark matter as being two different problems before. That is ignorance. Calling people incompetent for not being able to read the minds of physicists from a distance is sheer arrogance.

Re:Dark matter?

[Black Gold Alchemist]

Not to mention the more direct studies in which various distant objects were observed to detect occlusion events. Not enough events were detected to account for the idea of dark matter being composed of Brown Dwarfs and other small "normal" objects.

Re:Dark matter?

[Ungrounded Lightning]

Most calculations based on stellar orbits consistently come up with figures for dark matter of over 80% of the matter in the universe. There's more than four times as much dark matter as what we can see. And whatever dark matter is, it apparently is diffuse enough that we don't see it micro-lensing anything, and doesn't otherwise interact with light or other EM radiation, because we find no trace of it in the light that reaches earth from all corners of the universe;

There's two ways for "dark matter" to not be visible by microlensing:

  1) It's very diffuse rather than being organized into star-sized lumps.
  2) It's mostly compressed into planet-sized and smaller lumps - massive enough to hold a bunch of mass per lump but not enough for the lumps to produce detectable microlensing, sef-ignitte, collapse into black holes, or collect into "dust clouds" and obscure the background.

Only four times as much "dark matter" as "visible matter", eh? Solar systems seem to be organized fractally. I wonder if extending that fractical computation might predict enough "homeless planets", distributed in a mostly invisible way, to account for the "missing mass" and missing gravitational lensing?

Re:Dark matter?

[Ungrounded Lightning]

Calling people incompetent for not being able to read the minds of physicists from a distance is sheer arrogance.

Especially when the physicists use the same term, "dark matter" without qualifications, to refer to two allegedly separate problems.

If they're going to dumb it down for the newsies who dumb it down further for their readers, thus avoiding handing out any clues, they have only themselves to blame when the general public is clueless.

Re:Dark matter?

[Anonymous Coward]

Matter distorts spacetime, therefore it pushes on it in some way. A large collection of matter rotating around a point may be 'stirring' spacetime like a spoon in liquid. The matter in that galactic cluster appears to be rotating fast but locally it passes through space at a normal rate, but the space is itself moving too.

Ill take that Nobel now thanx

Re:Dark matter?

[Maritz]

Don't you think other WIMPS than neutrinos are still in contention? If the LHC were to discovery SUSY particles like the neutralino for example?

Re:Dark matter?

[Lost Race]

Gravitational turbulence? Eddies in the spacetime continuum?

Re:Dark matter?

[uninformedLuddite]

Do you really think astronomers are too dumb to think of all the non-stellar matter in and between the galaxies?

My over inflated sense of self worth has to say yes. It has no other options.

Re:Dark matter?

[Anonymous Coward]

Actually they're Massive Compact Halo Objects (MACHOs).

Re:Dark matter?

[Patch86]

One of the main reasons for discounting MACHOs has been lack of observational evidence, in terms of micro-lensing. If this study is right (that there is considerably more sub-luminal interstellar bric-a-brac out there than the current received wisdom), then presumably that does somewhat change the numbers, and lessens the amount of WIMPs required to balance the books.

They're claiming that free-floating Jupiter-sized objects outnumber stars (presumably including brown and red dwarfs) 2:1. They don't make any claims about smaller objects due to observational limits, which means we're talking quite a considerable chunk of extra matter if they're correct.

I'm not going to make any Quixotic attempts to work out how much extra matter that is, but I really hope someone else does :)

Using the word "may" in a title...

[Anonymous Coward]

...may be a sign of really poor journalism.

Either it is or it isn't. If there is too much ambiguity to make a statement about it, then it isn't news yet.

Re:Using the word "may" in a title...

[Intrepid imaginaut]

Only a Sith deals in absolutes.

nerdcred++

Re:Using the word "may" in a title...

[Neil Boekend]

Well, it's better than the default: take something very ambiguous and present it as truth.

Re:Using the word "may" in a title...

[captainpanic]

Either it is or it isn't.

That statement is a sign of someone not understanding statistics.

Re:Using the word "may" in a title...

[Anonymous Coward]

The new episodes don't count. Besides, it's a idiotic self-defeating quote ("only" is an absolute).

Re:Using the word "may" in a title...

[TapeCutter]

If you want absolute certainty, join a religion.

Re:Using the word "may" in a title...

[geoffrobinson]

"Only a Sith deals in absolutes."

That statement is an absolute. Just saying.

So...

[Dorsai65]

Which administration gets the blame for that?

Re:So...

[jefe7777]

anal administration gets a lot of bad press but it's really effective for some treatments...

Re:So...

[jellomizer]

Which ever one that you are not part of.
Those planets were either taxed out of orbit or Forced out of orbit by corporations with not government protection.
Maybe the planets residents overused solar energy and sucked their sun dry? Or the enemy on the other side of the globe decided it was a good idea to bow up the sun when it was night for them, as to destroy their sun.

wonderers

[one cup of coffee]

Well, the Greek word for wonderer is planitis. Seems even more appropriate in light of this report.

Re:wonderers

[tangelogee]

Well, the Greek word for wonderer is planitis. Seems even more appropriate in light of this report.

I wonder if you mean wander...

Re:wonderers

[gstoddart]

I think you mean "wanderer" -- as in they "wandered around the sky" not "wondered what was for lunch".

Re:wonderers

[MartinSchou]

No. The Greek word for wanderer is planitis. Well periplani̱theÃ.

Hint: To wonder and to wander is not the same. For instance, The Great Pyramid is a wonder of the world, but it sure as hell isn't a wanderer of the world.

Re:wonderers

[ginbot462]

The Great Pyramid is a wonder of the world, but it sure as hell isn't a wanderer of the world.

It's just "stunned".

Re:wonderers

[AGMW]

The Great Pyramid is a wonder of the world, but it sure as hell isn't a wanderer of the world.

It's just "stunned".

HELLO PYRAMID!

Re:wonderers

[one cup of coffee]

thanks, I I realized that right after I clicked, I was so excited by the fact that I thought I might make First Post.

Warp Drive

[The Bringer]

How much would it suck to collide with a randomly floating planet as you're ripping around the cosmos at warp 9?

Re:Warp Drive

[somersault]

Not much, seeing as you need to be in a "subspace" bubble to travel at warp speed.

Re:Warp Drive

[I'm not really here]

If you're ripping around the cosmos at warp 9, time and space are warping around you, so you'd never know the planet was there...

Re:Warp Drive

[gstoddart]

Not much, seeing as you need to be in a "subspace" bubble to travel at warp speed.

Yeah, but you still don't want to bump into things, and you still need to navigate.

That's what the deflector dish is for ... it's not like they could just run through a star due to the subspace bubble. You still need to avoid objects at warp speed.

Re:Warp Drive

[arunce]

The warp bubble would rip the objects.

Re:Warp Drive

[gstoddart]

The warp bubble would rip the objects.

Things like planets and stars? I highly doubt it.

If they're using a deflector beam to get microscopic particles out of the way, they're sure as hell not ripping through planets and stars.

I'm pretty sure if they did something like that, they'd pretty much be destroyed -- in rather a spectacular way I should think. You think a car driving into a wall creates carnage? A starship crashing into a star at warp speed is going to make one hell of a boom.

Re:Warp Drive

[arunce]

Not the ship, but the warped bubble it self would rip it. Can you imagine the energy used to warp between two points of space? Nobody can. Oh Star Trek... forget, I was kidding.

Today we have homeless planets...

[arunce]

tomorrow we will have homeless moons, rocks, asteroids etc etc etc... and dark matter will be reduced in a big 0.000001%.

Re:Today we have homeless planets...

[Black Parrot]

tomorrow we will have homeless moons, rocks, asteroids etc etc etc... and dark matter will be reduced in a big 0.000001%.

Except that they have to account for five times as much as what astronomers can see or infer exists.

Did it ever occur to you that the experts might actually know what they're talking about?

Re:Today we have homeless planets...

[arunce]

No doubt on that. But we have to assume the existence of hundreds more times normal/visible matter. After all there are some educated guesses that only 5% of the known universe is made of atoms. Even if you extrapolate 5000 "starless" planets per star, you still have to think about how massive a star can be.

Aliens among us...

[taiwanjohn]

So that's where homeless people come from!

Re:Aliens among us...

[The Bringer]

I prefer to refer to them as outdoorsy.

Re:Aliens among us...

[rubycodez]

in German I like to call them "gutter-seeky"

Would make a great way to reach the stars

[MichaelSmith]

If a four light year hop is too far maybe it will be possible for space craft to reach the nearest "homeless" planet, refuel and carry on.

Re:Would make a great way to reach the stars

[slim]

What manner of fuel do expect to find on the "homeless" planet?

Re:Would make a great way to reach the stars

[Anonymous Coward]

ummmmm.... care to explain that in more detail? You plan on landing on a large rock not orbiting a star. It will likely be a few degree Kelvin warmer than absolute zero. It will have no atmosphere. No food. And it will be at the bottom of a gravitational well. What part of this indicates it would be a good launching pad for space exploration?

Re:Would make a great way to reach the stars

[captainpanic]

What manner of fuel do expect to find on the "homeless" planet?

Slingshot?

Spaceships tend to just carry on also without fuel... the vacuum of space doesn't offer much friction.

Unless the planet happens to travel in the same direction at a similar speed, it wouldn't make much sense to slow down, refuel, and speed up again. Might as well wait until you're at the destination and slow down then. But a slingshot from such a planet might be nice!

Re:Would make a great way to reach the stars

[definate]

If there are "the homeless" on the planet, might I suggest Soylent Green?

Re:Would make a great way to reach the stars

[Black Parrot]

What manner of fuel do expect to find on the "homeless" planet?

More importantly, what do you find to *eat*?

I don't mind burning mummies to power my spaceship, but when it's dinnertime I expect fresh sapient brains on the plate.

Re:Would make a great way to reach the stars

[NatasRevol]

The gravitational well?

See gravitational slingshots.

http://en.wikipedia.org/wiki/Gravity_assist

Re:Would make a great way to reach the stars

[Anonymous Coward]

Not if the dude is looking to land on it for "fuel"

Re:Would make a great way to reach the stars

[MichaelSmith]

What manner of fuel do expect to find on the "homeless" planet?

Hydrogen.

Re:Would make a great way to reach the stars

[MichaelSmith]

Spaceships tend to just carry on also without fuel... the vacuum of space doesn't offer much friction.

Sure, but say you are on a slowboat with a continuous transit time to the next star of 1000 years. Thats foreseeable technology today. You use fusion reactors for energy but they need to be topped up with deuterium or some such from time to time. Your life support system leaks gasses. You need to stop from time to time to take on more hydrogen and oxygen (in the form of ice). Perhaps the galaxy would be colonised one step at a time (like the Pacific) as population pressure pushed people on to the next island (so to speak).

Re:Would make a great way to reach the stars

[MichaelSmith]

If you have matter (water, carbon, iron, etc) and energy (from a fusion reactor, perhaps) then you can make food. But you would have to stop at a planet to collect those things.

Re:Would make a great way to reach the stars

[MichaelSmith]

The homeless planets being discussed are gas giants. These planets have a lot of potential energy stored in their atmospheres. Jupiter, for example would be almost the same temperature without the sun. So there will be plenty of gaseous hydrogen with could be mined from the atmospheres. Any moons would be kept relatively warm by tidal effects from the primary so they may have gaseous atmospheres as well. The moons are likely to have a lot of water ice as well, which is useful to restock the life support system of a space craft on a long journey.

Re:Would make a great way to reach the stars

[slim]

Hydrogen in what form?

Re:Would make a great way to reach the stars

[MichaelSmith]

Gaseous, at least on the surface. I expect a gas giant located away from any star to be similar to Jupiter. Most of the heat on Jupiter comes from contraction of the planet anyway. Its more likely though that a planet like that would have moons similar to Europa, Titan, etc. They would be kept relatively warm by tidal warming from their primary. Depending on the technology available it may be easier to mine the atmospheres and surfaces of the moons than the atmosphere of the planet.

Not a piece of news since 10+ years

[VincenzoRomano]

http://en.wikipedia.org/wiki/Space:_1999

Idle?

[Anonymous Coward]

The "idle" tag is suspiciously missing...

Homeless planets throughout the galaxy?

[Black Parrot]

I guess the economy's bad *everywhere*.

Re:Homeless planets throughout the galaxy?

[TheOldFart]

You made me spit my coke everywhere... Thanks! :)

Lazy Stars

[digitaldc]

"the researchers estimated that there are nearly two free-floaters for every star in our galaxy."

Someone really needs to tell these stars to remember to flush when they are done with their solar discharges.

Now we only need...

[Robert Zenz]

...to find the five worlds in a Klemperer Rosette and see how far they've made it so far.

A new kind of space ship?

[definate]

Well, while I wouldn't think they'd be "space ships" in the classical sense.

I do wonder, would this not be a viable method of extremely long term, interstellar travel?

Find a "free-floater" (terrible name), build a perhaps subterranean civilization, somewhat colonize this planet, impart an impulse, and go for a ride for millions of years. Given we're advanced enough to even make it to one, we might even be able to attach "weak" but sustainable engines to it, such that we can slightly control it. It wouldn't be a terraformed planet, or similar, more like a moon, which we can live on, sustainably, regardless of the vacuum of space, and lack of sun. This would then essentially be a giant, "space ship".

Interesting idea.

Re:A new kind of space ship?

[Whalou]

You make it sound so simple!

Re:A new kind of space ship?

[MBGMorden]

The issue would be one of power. Law of conservation of energy and all that. Any people living on such a rock need energy to move around talk, and go about their daily lives. That energy has to come from somewhere. In our own cases, that's easy: 99% of the energy we use traces back to the sun in some way or another (geothermal is about the only naturally harnessable source that isn't solar - nucelar fission is available to societies that can harness it).

So in the end, such a rock would be useleess as a vessel unless it had a very active internal heating source, OR plenty of nuclear material. Even with that, I'd wager it'd be mighty hard to support a population of any size for too long.

Re:A new kind of space ship?

[Anonymous Coward]

Read Fritz Lieber's "The Wanderer".
It discusses exactly this.

Re:A new kind of space ship?

[Anonymous Coward]

The issue would be one of power. Law of conservation of energy and all that. Any people living on such a rock need energy to move around talk, and go about their daily lives. That energy has to come from somewhere. In our own cases, that's easy: 99% of the energy we use traces back to the sun in some way or another (geothermal is about the only naturally harnessable source that isn't solar - nuclear fission is available to societies that behave well, or already have The Bomb).

So in the end, such a rock would be useless as a vessel unless it had a very active internal heating source, OR plenty of nuclear material. Even with that, I'd wager it'd be mighty hard to support a population of any size for too long.

There, I fixed it for you.

Re:A new kind of space ship?

[onepoint]

It sounds so simple because the idea has a lot going for it. the lack of an energy resource is the only thing, but I am thinking that a deep enough mine, might produce geo-therm heat.

Where I perceive the problem to be is the evolution of the people on the planet, we can barely keep ourselves from getting killed every 40ish years, I would love to know what would happen on this journey of 10000+ years.

As for a way to guild the direction, well these things are Jupiter size, so I would guess we would jump on one, then work on some sort of small consistent thrust that over 5000 years, MIGHT move the routing. But it looks like we would be hitchhikers just a long for the ride first.

Now how would we detect one with 200 to 400 years of advance notice so we can send up a scouting vessel to see if it works.

Re:A new kind of space ship?

[Anonymous Coward]

Space 1999

Re:A new kind of space ship?

[SQLGuru]

more like a moon

That's no moon!

Re:A new kind of space ship?

[LWATCDR]

Well if they can manage De-De fusion then it may not be much of a problem. Or even better if they manage to develop direct conversion or zero-point energy sources then leaving their sun might become a really good idea if not necessary.
Yes Zero-point and direct conversion are well in the realm of science fiction but then so is moving a planet or even getting to a free floating world.
If you where exploiting enough energy you could have a problem with dumping the waste heat. Moving to a free floating planet would help keep the planet from cooking in it's own waste heat.
Or you could have people living on a large moon orbiting around a Jovian type super planet. They do tend to give of heat and you could have an Io type planet with lots of geothermal heating caused by tidal events.
Of course all of this is in the realm of cool science fiction reading.

Re:A new kind of space ship?

[Iamthecheese]

The issue would be one of power. Law of conservation of energy and all that. Any people living on such a rock need energy to move around talk, and go about their daily lives. That energy has to come from somewhere. In our own cases, that's easy: 99% of the energy we use traces back to the sun in some way or another (geothermal is about the only naturally harnessable source that isn't solar - nuclear fission is available to societies that behave well, or already have The Bomb).

So in the end, such a rock would be useless as a vessel unless it had a very active internal heating source, plenty of nuclear material, or hydrogen where the using society had hydrogen fusion technology. Even with that, I'd wager it'd be mighty hard to support a population of any size for too long.

There, I fixed it for you.

There, I fixed that "I fixed it for you" for you.

Re:A new kind of space ship?

[MozeeToby]

Or Niven's Fleet of Worlds, or watch Space 1999.

Or read "A Pail of Air" which is about survivors of a freak accident that causes the earth to become one of these (I suspect that the physics of this story are off by orders of magnitude, but it's still a fun read for some reason).

Re:A new kind of space ship?

[Aidtopia]

This idea is similar to applying a force to the sun and dragging the entire solar system. The author of that piece incorporated the idea into his novel C.U.S.P.

Re:A new kind of space ship?

[pnewhook]

Interesting idea.

They already did that in a Star Trek episode.

Re:A new kind of space ship?

[An ominous Cow art]

Or "The Jupiter Theft"

I remember "A Pail of Air" - yes, fun to read.

Re:A new kind of space ship?

[WorBlux]

Fusion, space far from being empty contains a lot of hydrogen. Build arrays of the surface that could bind any hydrogen that hits it, and use the fusion to power the society.

Re:A new kind of space ship?

[Anonymous Coward]

You might want to check out the Vasin-Shcherbakov Theory.

It refers to a thoery that our moon could be an ancient spaceship.

Re:A new kind of space ship?

[WorBlux]

Not to mention there's probably some mineral on the surface that can already to that. Strip the hydrogen from it, spread it back on the planet's surface to recharge over the next thousand years.

Re:A new kind of space ship?

[nospam007]

"I do wonder, would this not be a viable method of extremely long term, interstellar travel?"

It's the damned Pierson's Puppeteers fleeing from the exploding core.

Re:A new kind of space ship?

[Anonymous Coward]

Fusion? While you are floating through space, you'd be hitting hydrogen (like bugs on a windshield), which is pretty much everywhere. Granted, not a lot, but then a whole planet would be a pretty bug surface to capture atoms on. (We are talking about engineering on an interplanetary scale here anyway).

Re:A new kind of space ship?

[CatsupBoy]

The core of this planet has been hot for billions of years, perhaps it could be coaxed it into staying hot for billions more. A couple of well placed moons might gravitationally provide some heat in the core.

Also the planet could be stocked with water to provide thermodynamic energy, O2, and water for us and plants. Not sure how effective a big layer of ice is against gamma radiation, but it couldnt hurt.

And who says we have to have a large population, just big enough to withstand any disasters that might befall us along the way (earthquakes, radiation, comets, etc...).

Re:A new kind of space ship?

[Dog-Cow]

After millions of years, why would expect there to be any heat left in the core to provide geothermal energy? These things don't go near any stars (or they'd be captured).

Re:A new kind of space ship?

[TheCouchPotatoFamine]

Have to respond to you. It's not heat from the Sun that warms earth's interior, it's radioactive elements in earth's composition, and they are actually wrapped around the core like an "electric blanket".

From http://geology.about.com/od/mineral_resources/a/geothermal.htm

Earth's Heat Source

OK, so geothermal energy is heat from underground. But why is the Earth hot at all?

To a first approximation, Earth's heat comes from radioactive decay of three elements: uranium, thorium and potassium. We think that the iron core has almost none of these, while the overlying mantle has only small amounts. The crust, just 1 percent of the Earth's bulk, holds about half as much of these radiogenic elements as the whole mantle beneath it (which is 67 percent of the Earth). In effect, the crust acts like an electric blanket upon the rest of the planet.

Lesser amounts of heat are produced by various physico-chemical means: freezing of liquid iron in the inner core, mineral phase changes, impacts from outer space, friction from Earth tides and more. And a significant amount of heat flows out of the Earth simply because the planet is cooling, as it has since its birth 4.6 billion years ago.

The exact numbers for all these factors are highly uncertain because the Earth's heat budget relies on details of the planet's structure, which is still being discovered. Also, Earth has evolved, and we cannot assume what its structure was during the deep past. Finally, plate-tectonic motions of the crust have been rearranging that electric blanket for eons. The Earth's heat budget is a contentious topic among specialists. Thankfully, we can exploit geothermal energy without that knowledge.

Re:A new kind of space ship?

[softWare3ngineer]

i shed a tear as i read and understood the reference :P

Re:A new kind of space ship?

[onepoint]

if we can fly to one of these places, there is no doubt ( due to it's size ) that there is a way to dig way deep into it's mantel to get stored heat energy or tap into some sort of gravity effect to produce energy.

Re:A new kind of space ship?

[sjames]

It sounds like the Puppeteer home worlds in Niven's Known Space.

Re:A new kind of space ship?

[RespekMyAthorati]

It wouldn't be a terraformed planet, or similar, more like a moon...

That's no moon!

The year 1994....

[kungfugleek]

Ruby Spears Productions was only wrong about the year:

The year 1994: From out of space comes a runaway planet, hurtling between the Earth and the Moon...

Thundarr Intro

Re:The year 1994....

[Chris Mattern]

Lords of Light!

Re:The year 1994....

[ginbot462]

Demon dogs!

Re:The year 1994....

[Anonymous Coward]

That might be how we got a moon in the first place

Not really planets

[Xtifr]

Tch, they're not really planets, right? I mean, if they're not orbiting a star, then they can't have "cleared the neighborhood of their orbit". Yet one more reason the IAU's current definition is so idiotic. (Besides the fact that it suggests that Mercury is more like Jupiter than it is like Ceres.)

Re:Not really planets

[Anonymous Coward]

Well, you are right. They are actually substars, sub-brown dwarfs, failed brown dwarfs, rogue planets or planetars.

I really don't understand what your confusion is all about, it's all well-defined.

Re:Not really planets

[gQuigs]

Depends on your definition of cleared.

I assume they meant: to remove people or objects from
Alternatively: so as not to be in contact with or near

[http://dictionary.reference.com/browse/clear]

Re:Not really planets

[hogghogg]

Tch, they're not really planets, right? I mean, if they're not orbiting a star, then they can't have "cleared the neighborhood of their orbit". Yet one more reason the IAU's current definition is so idiotic. (Besides the fact that it suggests that Mercury is more like Jupiter than it is like Ceres.)

Yes, they are planets most likely, because they probably formed around a star and then got kicked out dynamically. This is expected generically in models of how solar systems form and evolve (in particular we think it happened multiple times in our own Solar System).

Re:Not really planets

[Turnpike Lad]

Have we ever seen an object pass through our solar system in a hyperbolic orbit? If there are so many objects in interstellar space you'd think we'd see a few of them slingshotting around the sun now and then,

Re:Not really planets

[mcmonkey]

Tch, they're not really planets, right? I mean, if they're not orbiting a star, then they can't have "cleared the neighborhood of their orbit". Yet one more reason the IAU's current definition is so idiotic. (Besides the fact that it suggests that Mercury is more like Jupiter than it is like Ceres.)

My first thought was also, these are not planets. But I don't know if that's an issue with the IAU definition.

First, obviously not a planet--doesn't orbit a star. But I'd say that's a feature, not a bug, of the definition.

Status as a 'Planet' tells you not only something of the objects origins but also it's current state. These objects share the origins of planets, but have a different current state. We just need a different term to capture that distinction.

I suggest, 'objects formerly known as planets'.

Re:Not really planets

[LongearedBat]

I suggest, 'objects formerly known as planets'.

Yes, and we can use an unpronouncable symbol instead of a proper name, commonly known as "planet symbol". ;)

Re:Not really planets

[Anonymous Coward]

That reminds me of all those people who still say "We have 8 planets in our solar system, or 9 if you still count Pluto"

A more correct version of that would be "We have 8 planets in our solar system, or tens of thousands if you still count Pluto"

Personally I think your claim that our solar system Does have tens of thousands of planets is much more 'idiotic' than the current definition is.

Re:Not really planets

[Anonymous Coward]

=> I suggest, 'objects formerly known as planets'.

You mean like: "The artist formerly known as Prince"?

Re:Not really planets

[TemporalBeing]

Tch, they're not really planets, right? I mean, if they're not orbiting a star, then they can't have "cleared the neighborhood of their orbit". Yet one more reason the IAU's current definition is so idiotic. (Besides the fact that it suggests that Mercury is more like Jupiter than it is like Ceres.)

My first thought was also, these are not planets. But I don't know if that's an issue with the IAU definition.

First, obviously not a planet--doesn't orbit a star. But I'd say that's a feature, not a bug, of the definition.

Status as a 'Planet' tells you not only something of the objects origins but also it's current state. These objects share the origins of planets, but have a different current state. We just need a different term to capture that distinction.

I suggest, 'objects formerly known as planets'.

Well yes and no - they could be a result of dieing stars that loss enough gravitational force to carry them on, or they could be far enough away from the star they are orbiting that we just don't know which star(s) it is yet. Numerous reasons why they could be there and yet still be officially called planets.

My first thought was, wonder if this accounts for the whole "Dark Matter" issue.

Re:Not really planets

[element-o.p.]

Except that, to quote Douglas Adams, "Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is..." Couple that with the fact that in galactic timescales, we've only been around to notice such things for a tiny blip of time, and we've only been able to understand what we see in the heavens for an even tinier fraction of that time, and I would think that odds of us seeing and recognizing such interstellar objects would be vanishingly small.

But, not being a professional (or even reasonably competent amateur) astronomer, I could be completely wrong here. <shrug>

Re:Not really planets

[Anonymous Coward]

I suggest, 'objects formerly known as planets'.

Hmm, Ofkap ... not a terrible sounding initialism... Time to write a new sci-fi!

Re:Not really planets

[Xtifr]

Thinking the current definition of planet is stupid is not the same thing as being confused about it. I agree that Pluto and Eris are a different class of object from the traditional planets (you notice I didn't mention Pluto in my complaint), but we already have two very different classes of object covered by the classical term (gas giants and rocky planets). The insistence that dwarf planets aren't "really" planets makes about as much sense to me as adding "has hair" to the definition of mammal, and then insisting that naked mole rats aren't "really" mammals, but instead fall into a separate category of "hairless mammals", which is not (for some unfathomable reason) a subset of mammal.

The IAU went to all the trouble of reclassifying Ceres (long overdue in my opinion), but they didn't take the sensible approach of putting it in the same category as Mercury, which it strongly resembles. Instead, they left Mercury lumped in with the very different Jupiter, and put Ceres in the same class as the very different Pluto and Eris. That's just stupid!

Note that we still haven't (technically) discovered any planets that we know of outside of our own system, because the ridiculous current definition of planet makes it impossible to determine for sure whether an exoplanet (even a Jovian one) has cleaned its neighborhood. Its entirely possible that there are Jovian objects or even sub-brown dwarves that will have to be classified as "dwarf planets". Again, insanely stupid, IMO.

I won't even get into the question of why Luna and Ganymede shouldn't be classified as planets (while still being classified as moons), though I think they should be.

Bottom line, the IAU hijacked a common English term and gave it a bizarre, counter-intuitive, and illogical definition for obscure reasons that smell strongly of internal politics. I mean, I understand that the IAU may have been sick and tired of arguing about nomenclature, and were actively looking for a compromise position, but the compromise they (or at least, some subset large enough to form a quorum) chose sounds more like a joke proposal someone came up with after too many post-session drinks, rather than anything anyone should have ever taken seriously.

Re:Not really planets

[Xtifr]

Did I say anything about Pluto? Did I even begin to suggest that Pluto or other Kuiper belt objects should be a planet? No, I mentioned Mercury, Jupiter and Ceres. Period!

Saying "we have eight" is stupid no matter how you view Pluto, because it ignores Ceres. The only correct thing the IAU did was reclassify Ceres, but they did a half-assed job of that! Is there really any sensible reason to classify Ceres with those tens of thousands of Kuiper belt objects, rather than putting it in the same category as its close cousin Mercury?

On the other hand, I have no idea why you think "the solar system has tens of thousands of planets" is idiotic if it falls out from a more sensible definition of planet, even though that's not the position I'm arguing. Would you call classifying birds (Aves) in the category-formerly-known-as-lizards idiotic? Classifying quarks as elementary objects, even though it means the proton and neutron no longer meet that definition? Science marches on, dude!

Re:Not really planets

[Anonymous Coward]

since planets all have cool symbols, i guess these would have a symbol too...maybe a cool new glyph for each one, which means "the object formerly known as prince centauri" (thats the dead star near alpha centauri which the object used to orbit around)

Re:Not really planets

[gr8dude]

It is interesting that 'planet' comes from 'wanderer' in Greek - that refers to bodies that move in a weird way in the sky (from their perspective back then, the trajectories didn't make sense).

Now we discovered wandering planets, which makes them more of a planet than actual planets...

disaster

[Anonymous Coward]

And what happens when one the size of Jupiter passes through a solar system such as ours?

Re:disaster

[TheOldFart]

I don't know about you but that's when the Christian right would scream "Rapture"...

Re:disaster

[rubycodez]

it would be more like a "rupture"

Space 1999

[Altesse]

Obligatory reference : Space 1999. Greatest show ever.

Re:Space 1999

[TempestRose]

All we have to do is put all the leftover radioactive crap on the moon. What could possibly go wrong?

That's no homeless planet.

[Coldfinger]

It's a space station!

Halo Worlds

[Lebrun]

This reminds me of the Halo Worlds depicted in Charles Stross's Permanence. In the novel, those systems, usually orbiting a brown dwarf, accounted for the missing mass in the universe, so it turned out there was no 'dark matter'. The halo worlds were also the way for humanity to first venture into interstellar travel.

I know what's out there

[Anonymous Coward]

The missing Dreadnaught fleet.

Obviously...

[BenSchuarmer]

The Scientists are getting us ready to tell us the truth about Nibiru

Classic movie reference

[DaveV1.0]

So, this means that "When Worlds Collide" will be lived out, right? In 2012, right?

Homeless planets

[Anonymous Coward]

So, there are planets out there that live under overpasses with signs that say "Will work for sun"?

generically expected; great if found

[hogghogg]

Free-floating planets are generically expected: Essentially all models for how solar systems like ours (and the others we now know) involve dynamical interactions that would kick out planets at high velocity, leaving them unbound. Astronomers have expected to find these for decades, but have been unable to do so because a planet not warmed by a nearby star gets cold fast (hundreds of thousands to millions of years) and therefore invisible even in the infrared. This result is very important if correct, because gravitational lensing is an emission-insensitive way to find the planets. And yes, IAAA! (ps As for whether they are "spacecraft": I love that idea, but the "people" onboard probably wouldn't give the planet an impulse themselves (way, way, espensivo), they would make use of a free-floater passing by and hitch the ride.)

Re:generically expected; great if found

[drooling-dog]

Absolutely. If you play with N-body gravitational simulations, you see stuff getting flung out of orbital systems all the time, and usually at very high velocities. It generally happens before a system stabilizes, or when something new enters from outside and disrupts established orbits. I've personally messed up quite a few "solar systems" just by plopping a fairly massive foreign object in the general neighborhood. The screams are silenced by the vacuum of space. There's no reason it couldn't happen to us, either, if you need yet another calamity to worry about...

Re:generically expected; great if found

[Anonymous Coward]

um great? what if one comes into collision course with earth?

Re:generically expected; great if found

[wierd_w]

As a matter of curiosity, how could astronomers tell the difference between a distant spaceship equipped with an alcubierre warp drive and a rouge planetoid?

Both would exhibit localized micro-lensing, and depending on the tradjectory of the objects (in both cases), might appear to be standing still, or moving at sub-luminal speeds. (Since they are not emitting light that would red or blue shift if the object was moving toward or away.) The spaceship equipped with such a device would have to create a very strong dimple in spacetime to create a fast moving bubble, which would be mathematically identical to a gravity well, and would bend light in exactly the same ways.

I realize that such devices are de-facto science fictional, but this is a hypothetical question.

Re:generically expected; great if found

[DanielRavenNest]

Number of bullets (rogue planets): roughly 1 per 8 square light years
Size of target (the Earth): 0.02 light seconds x 0.02 light seconds
Number of seconds in a year: 31,556,925
Impact probablility: 19,916,790,309,112,500,000 to 1

Assume rogue planets have random velocities of 100 km/s (probably too high a number)
Then bullet frequency will be around one per 10,000 years.
So impact probability per year is that very large number above times 10,000.
Stop worrying.

Re:generically expected; great if found

[Anonymous Coward]

Only 100km/s as the velocity of a planet? Our planet moves through space much faster than that, and we're stuck in the gravitational pull of a solar system. A planet that had a velocity high enough to escape a solar system, then it's probably moving considerably fast. I am assuming that planets are formed during the creation of a solar system through one of those "star factory" structures as the remnants that didn't compress into the star. I honestly have no idea how planets are formed so please correct any of my ignorant mistakes.

Re:generically expected; great if found

[Anonymous Coward]

Nevermind, I was thinking km/h. I retract the previous post.

Warp Drive

[TheOldFart]

That would put a hamper on a warp speed jaunt... Is that a super nova? No, it was Billy Joe smashing into a free floater...

All our energy is NUCLEAR

[mangu]

In our own cases, that's easy: 99% of the energy we use traces back to the sun in some way or another (geothermal is about the only naturally harnessable source that isn't solar - nuclear fission is available to societies that can harness it).

In the end, all this energy comes from nuclear reactions, either fusion in the sun of fission in the interior of the earth or nuclear reactors.

Assuming an advanced enough technology, it's possible to extract nuclear energy from any atom except iron. It's reasonable to assume that a civilization advanced enough to reach an extra-solar planet would have no problem in extracting energy from it.

Kind of sad, but...

[HeyBob!]

At first I was kind of sad thinking about all those billions of frozen planets floating around out there, with no chance of the kind of life that could explore the universe (there may be life on a hot Jupiter type planet, but I doubt they could build telescopes and space ships)

But then I thought about advanced civilizations - really advanced. They could use these wandering planets for their resources - it could be a good series of sci-fi books
"The Planet Miners"

Re:Kind of sad, but...

[regular_guy]

Have you read "The Wanderer" by Fritz Leiber? Might be a good start.

Re:Kind of sad, but...

[HeyBob!]

Thanks - I'll check it out

Re:Kind of sad, but...

[Anonymous Coward]

Jupiter type planet, but I doubt they could build telescopes and space ships

Read The Algebraist by Ian M Banks. It explores this concept in a really interesting, debaucherous way.

captcha: orbiter :)

Re:Kind of sad, but...

[HeyBob!]

Thanks - another great find!

Free-floaters?

[GodfatherofSoul]

What a crappy name. I say we call them hippie planets. Aimless, shiftless, wandering space with no rhyme or reason and expecting a hard-working star to just show up and carry their dead weight. I bet they're devoid of water (and soap) as well.

Suits me - "planet" means "wanderer"

[Anonymous Coward]

It's from the Greek word "planasthai, to wander."

new space ship moon of wandering gas giant.

[rubycodez]

suppose "planet" is large moon of homeless gas giant that is being mined for He3

Ringworld anyone?

[Anonymous Coward]

Anyone read that book? Kinda covers this.

Could these be the 'Dark Matter'

[Agent0013]

Scientists talk about there needing to be more matter in the galaxies than they can calculate from observations. Now we are hearing there may be even more free wandering planets than there are stars. Is it possible that all this extra matter that does not give off light could account for the 'Dark Matter'?

Star Seeds

[badass fish]

I have always believed that there were "rogue" planets that if they wandered into a different gas cloud or system than their nursery would act as a seed for stars. also if we have learned anything is that jupiter and plus sized planets usually have many moons associated with them. lets say a large rocky planet passes thru a gas cloud, it could easily attract enough matter to become a jupiter class planet.

Could one enter our solar system?

[GayBliss]

I wonder if these homeless planets are at least locked into position in the Milky Way, or if they are truly wandering around. Could one suddenly show up in our neighborhood and maybe enter our solar system? I can't image that would end well.

Re:Could one enter our solar system?

[Sperbels]

Sure it could. But not even the stars are locked in position in the Milky Way. The stars wander around a bit too and have near misses and collisions. It's just that space is so big, and they're not moving very quickly relative to each other that it happens infrequently. And since it's so big, the odds of even two stars colliding are very unlikely. It's like throwing two bottles into separate sides of the Atlantic and waiting for them to collide.

*Rogue*

[adavies42]

The correct term is rogue planet. Almost anyone who's interested in this is going to have read enough science fiction to know what a rogue planet is, so why make up a new name?

homeless?

[slick7]

I guess the homeless planets live under bridges in cardboard boxes... or like a wandering Nibiru.

Such planets may be safer places to live...

[Paul Fernhout]

A planet far away from a sun, perhaps wandering hundreds of millions of light years from a galactic core, may be less susceptible to things like supernovas or galactic superwaves.
http://www.etheric.com/LaViolette/Predict.html
" Galactic Core Explosions - prevailing concept (1980): At the time of this prediction, astronomers believed that the cores of galaxies, including our own, become active ("explode") about every 10 to 100 million years and stay active for about a million years. Since our own Galactic core presently appears quiescent, they believed it would likely remain inactive for many tens of millions of years. Although, in 1977, astronomer Jan Oort cited evidence that our Galactic core has been active within the past 10,000 years."

Our own solar system is far to the edge of a galaxy.

Ecosystems on such planets might be sustained by heat produced at the boundary of the planets nickel-iron core, or for gas giants, in moons circling the larger primary that are heated by tidal forces.

It would not suprise me to learn that most life only exists on those kind of remote planets. On Earth, there is much life on the distant ocean floor, and much variety, because it is such a relatively stable place. Those rogue planets might be wonderful stable homes for life in that sense.

Wrong article!

[Anonymous Coward]

Both the summary and the news piece it links to cite the wrong nature article. That's about planets with retrograde orbits (like Pluto). The one about exoplanets is here:

http://www.nature.com/nature/journal/v473/n7347/full/nature10092.html

fer cryin out loud.

Re:Wrong article!

[Anonymous Coward]

Damn it. It seems to be a rule that posting corrections leads to more mistakes. I didn't mean to say Pluto had a retrograde orbit. That should have read ...retrograde orbits (highly disrupted orbits like that of Pluto)...

anyway go read the paper.

Rouge Planets?

[Anonymous Coward]

They're talking about "Rouge Planets" right? I though it was already pretty accepted that they're were a lot of them out there. Its even possible that they resulted in the current state of our solar system. Earth suffered a massive impact early in its history that created the moon, and I don't believe Jupiter's gravity fully explains why the asteroid belt didn't form into a planet. Pluto might even bee one given its very eccentric orbit, Its not likely but possible.

Creation theories on hold, could we observe it?

[Ungrounded Lightning]

[baryon shortage on helium density evidence], [insufficient fragmentation in molecular clouds], ... it would require an insanely HUGE number of [free roaming planets] to explain dark matter observations.

Thought experiment:

Leave aside problems like not having enough baryons and models not predicting 80% of them (by mass) might organize into free roaming planets.

If there WERE that many free roaming planets would there be an appropriate size and arrangement of them to explain the observations?

And if so, are there observations we could make that would distinguish such a massive fleet of wandering planets from clouds of truly invisible, gravitationally interaction only, dark matter?

Re:Creation theories on hold, could we observe it?

[melikamp]

Looks like planets form out of the collapsing molecular clouds. What if there is more dark matter in galaxies which experienced more star formation? Would that nudge us toward accepting that the invisible mass is carried by planetesimals? Anyway, we can almost see protostars already, so I'll give 100-300 years tops for us to have a really good model for star system formation.

And can you please tell us more about not having enough baryons?

Nope - Not Planets!

[pugugly]

I note for the record that, regardless of the size of the objects, since they are not in an 'orbit' they cannot have 'Cleared their orbital Path' and thus cannot be 'Planets'.

They're "Over-sized Free-roaming gravitationally aggregated Pluto-like Objects"

SUCK ON THAT TYSON!!!!

{G} - Pug

And lo, without the pay wall

[Anonymous Coward]

http://arxiv.org/abs/1011.2501

Dark Matter?

[Anonymous Coward]

Isn't it far more likely that the calculations of the things we Do know about, the things we can see, some things we cant but know are there, are wrong?

Uh, you mean like "ROGUE" Planets?

[DarthVain]

Seriously, where did homeless come from all of a sudden?