Planets Without Stars or Mini-Solar Systems? 149
iamlucky13 writes "An article today on space.com discusses the discovery of 6 objects by the European Southern Observatory in Chile that are smaller than typical brown dwarfs, larger than Jupiter, and not orbiting any stars. The objects are surrounded by disks of gas and dust possibly similar to the early solar system. In addition to presenting astronomers with a new group of objects to study, the finding also deepens the debate over what makes a planet. The scientists responsible for the discovery sidestep the question by calling them 'Planetary Mass Objects,' or planemos."
Planimals? Planetimals? (Score:3, Funny)
Ok, it doesn't really mesh with the whole 'Mass Object' extension but I'm fairly certain the general public could deal with it much better this way. Besides, if you throw something like 'planemos' out to Jack & Jenny Sixpack, Planimals is the innevitable result.
-xski
Re:Planimals? Planetimals? (Score:2)
From the "experts" @ About.com
Planetesimals refers to a phase in the build-up process toward planet formation in a young solar system. Generally, the term is equated to "asteroid sized bodies" (0.5- 25 miles across) that coalesce or "accrete" to larger sized bodies, on the way to planetary objects. This definition, of course, means that one would only find "planetesimals" in a young solar system still in the process of formation. One would not fi
Re:Planimals? Planetimals? (Score:2)
True 'planets' then (Score:5, Interesting)
Comment removed (Score:5, Interesting)
Re:True 'planets' then (Score:4, Interesting)
Not knowing the time scales involved, I'm just going to throw this out as a possibility: if the orbital period of these odd planets around the galaxy is large enough, then the gravitational landscape on each revolution will be so different that the odd planet will hardly have a regular orbit. Alternatively, could it not eventually be trapped by a star? If so, one could hardly call its journey from wherever it started to the capturing star an orderly orbit.
Re:True 'planets' then (Score:1)
There is a theory that this is what happened to Pluto [wikipedia.org]. Recall that Pluto has a completely different composition to any other planet in our solar system and many argue it to be a comet or other such body. It's orbit is inclined to the plane upon which the rest of the solar system is found, and during a short period of it's orbit it is closer
Pluto is not extra-solar (Score:2)
Formation? (was: Re:True 'planets' then) (Score:2)
To any Pierson's Puppeteer: I'm over here! (though, I do not know how much pure luck was involved in my birth...)
(for those, who still don't get it:
http://en.wikipedia.org/wiki/Ringworld [wikipedia.org]
)
Re:True 'planets' then (Score:3, Informative)
The problem with that definition is that the sun was initially included as a planet because it looked like moving around the stars.
So when the initial definition of a word is based on false assumptions, it is probably hard to save the ass of that word with further discoveries 3000 y
Re:True 'planets' then (Score:1)
So they're angsty "teenage" planets wandering through dark places for no particular reason...
Re:True 'planets' then (Score:2)
actually? (Score:1, Informative)
Dark Matter (Score:5, Interesting)
I guess the question is how many of these would it take fill up the "dark matter" quotient we think exists.
Re:Dark Matter (Score:5, Informative)
Re:Dark Matter (Score:5, Informative)
Re:Dark Matter (Score:2)
It's all Dyson Spheres [wikipedia.org]
Re:Dark Matter (Score:1)
If they did, it would be great, because it would mean that would be lots of planets between here and nearby stars. That would make interstellar travel considerably easier because humanity could move outwards very gradually.
Re:Dark Matter (Score:2)
Incidentally, huge mass isn't necessarily an obstacle to life or even colonization; there are potentially regions around big planets where the gravity and pressure are tolerable and where one could "float".
Re:Dark Matter (Score:1)
Is the dark matter quotient half full or half empty?
Re:Dark Matter (Score:4, Informative)
Re:Dark Matter (Score:1)
Re:Dark Matter (Score:2)
One of my minor crusades on
The discovery of these small objects s
Re:Dark Matter (Score:2)
Why haven't I heard about this before? (Score:3, Funny)
Re:Why haven't I heard about this before? (Score:2)
You watched *every* episode? Including the Enterprise episode "Rogue Planet"?
Actually, probably best not to admit it if you did.
Re:Why haven't I heard about this before? (Score:1)
And for the geek record, I haven't seen EVERY episode... There are about 5 episodes of TOS, 50% of Voyager, and 80% of DS9 I haven't seen. I have seen every Enterprise and TNG, however. I've only seen 2 epidosdes
Re:Why haven't I heard about this before? (Score:1)
Re:Why haven't I heard about this before? (Score:1)
Re:Why haven't I heard about this before? (Score:1)
Re:Why haven't I heard about this before? (Score:2)
Re:Why haven't I heard about this before? (Score:2)
Re:Why haven't I heard about this before? (Score:2)
Re:Why haven't I heard about this before? (Score:2)
Re:Why haven't I heard about this before? (Score:2)
Re:Why haven't I heard about this before? (Score:2)
http://www.startrek.com/startrek/view/series/TOS/
Until they come up with a better definition of planet, I say that was a great reference.
in Chile? (Score:2, Funny)
Why is this not the norm? (Score:3, Interesting)
For example, really how large a whack from a body with the right vectors is needed to send pluto escaping off in some mad direction? Anyone care to calculate how much force is needed to do it?
Re:Why is this not the norm? (Score:2)
A whole bunch. In round figures.
Re:Why is this not the norm? (Score:1)
Since you stipulated that the body would have the right vectors (relative speed and direction) the whack need only be calculated in terms of mass. According to my careful and precise calculations it would take a whack with the mass of exactly 733433 Volkswagens per Pluto. This is to send Pluto escaping off in some direction. Further calculation is needed to determine if said
Re:Why is this not the norm? (Score:1)
Re:Why is this not the norm? (Score:2)
Re:Why is this not the norm? (Score:2)
That's assuming an impact (Score:2)
mod parent up! (Score:2)
just what I was about to say, more or less. Pluto is really light and far from the Sun, I guess (without basing this guess on any fact) with a Neptune sized object on a pretty excentric orbit getting close to Pluto might do it, but idk what it would take to achieve such a thing tho.
However for achieving that on an object such as a kind of brown dwarf, I'm not sure but I think it would have to be from a binary system to have been slashdotted away like this.
Planet or moon? (Score:4, Funny)
Re:Planet or moon? (Score:2)
Solar system (Score:2, Insightful)
Solar system [wikipedia.org] refers to the Sun and its planets.
Re:Network of wormholes (Score:2)
Maybe an alien ship (Score:1)
Re:Maybe an alien ship (Score:1)
Re:Maybe an alien ship (Score:2)
Re:Maybe an alien ship (Score:2)
" The objects are surrounded by disks of gas and dust"
Has everyone forgotten Star Trek the Motion Picture? That sounds like V ger to me.
the finding also deepens the debate over what make (Score:5, Insightful)
There is nothing deep about what to call by the name 'planet'. Once there was a clear delineation between planets and non-planets. Now there isn't because we've seen objects that straddle the divide set by the old definition. Just define some new words. If astronomers can solve the solar neutrino problem then surely they can solve the 'define planet' problem. Reminds me of Wadler's Law [blogspot.com].
Re:the finding also deepens the debate over what m (Score:1, Insightful)
Well, we could announce some proclamation from the balcony of the IAU's [iau.org] Mobile Oppression Palace, but since it's such a complete astronomical non-issue (what something's called makes no difference to how you study it) don't you think it's nice to let the people who care enough to debate it decide?
So, over to you!
No need. (Score:5, Interesting)
The Periodic Table of the Elements makes a lot of sense, because you can make a lot of predictions about the properties of an element based on where it is in the table. There are some oddities, sure, but by and large it is an extremely intuitive system. By comparison, knowing that a star is K or G tells you very little. You can make some inferences, by factoring in the abundances of the elements, the diameter of the star, the overall distribution of the electromagnetic radiation, etc, but if you're going to have to add in vast amounts of additional information to get anywhere, you might as well use that information in the name and have done with it.
For planets, asteroids, etc, it's much the same thing. By using too little information to determine the classification, you end up having to add vast amounts more information later on to produce subcategories, exceptions or new names entirely. That makes no sense to me whatsoever. Even a good naming system will need additions made to it, but it should be consistant with what is already there, and it should be easy to understand the relationships.
Since this is about planets, I'll use those as an illustration. Planets form around stars from the debris in the accretion disk, plus captured material from the stellar nursery in which the star formed, minus material "evaporated" from the system by the solar winds accelerating it, and minus material captured by other stars or gravitational sources. The process of condensing planets is slow, though apparently not as slow as once thought, which means that the material in the accretion disk will be sorted. In our own solar system, it seems to be that heavier elements are more common close to the sun and lighter ones are more common further away. (Mercury is unbelievably dense, for example, whereas Pluto seems to be little more than an iceball.)
However, because you need less energy to accelerate a lower mass, and because elemental hydrogen only forms a solid under extreme pressures, these will ALL have abundances of elements that are skewed (possibly by a lot, for inner planets, as the solar winds are much stronger) from the ratios observed on much larger scales (say, in the galaxy or the observable universe). Stars, on the other hand, are mostly composed of the extremely light elements and fit the expected abundances very nicely. As the gravitational field is reduced, the skew should increase, as it would require that much less energy for something to be ripped away, if it's free. (Obviously, hydrogen that has reacted with oxygen to form water is going to require much more energy than elemental hydrogen alone.) So, the composition tells us a lot about where something forms, how quickly it accumulated mass and how long it took. It would seem obvious, then, that composition should bear a major role in deciding what to call something.
The other "obvious" one would be structure. The "asteroid" recently observed to be 45% empty space (sand is 25%) would probably merit a new classification. Most asteroids probably have multiple "centers" around which they have congealed/collided. Certainly, the two comets that have broken up have had multiple centers, not a single rocky core. By comparison, the gas giants have a single center (duh!), as does the Earth and Venus, probably Mars as well, not sure if there's enough data on the others. But even with that, we can clearly see a logical distinction (as opposed to an arbitrary one) that can clearly distinguish between two very
Re:the finding also deepens the debate over what m (Score:2)
This applies to every endeavor of human thought, not just science.
This new slashdot.org template sucks!!!!!! (Score:1)
Re:This new slashdot.org template sucks!!!!!! (Score:1)
Have you forgotten http://shit.slashdot.org/ [slashdot.org] already?
Re:This new slashdot.org template sucks!!!!!! (Score:1)
yeah, it looks very GNOME-ish (not that I don't like GNOME) plus it's big, I mean eveyrthing takes more place on the screen.
If only the new layout was an option (although one by default)
Star systems without a star (Score:3, Interesting)
but lack the mass to ignite a sustained fusion reaction in the core of the system.
How many others could be out there that we can't see?
Re:Star systems without a star (Score:2)
Interesting question. Perhaps enough to account for the missing mass?
Hmmm... (Score:3, Insightful)
Re:Hmmm... (Score:2)
Re:Hmmm... (Score:2)
Re:Hmmm... (Score:2)
My favorite answer ... (Score:2)
This would settle the question forever, since it would immediately follow from the definition that there can't be any more planets anywhere in the universe.
Those troube-making astronomers would just have to invent a new term for similar objects elsewhere in the universe. Or in our solar system, for that matter. It's about time they di
Re:My favorite answer ... (Score:2)
The taxonomy of celestrial objects are not exactly scientifically done in astronomy,IMHO. But the bottom line? The key parameters for these objects are: mass, density and temperature. These three parameters would *fairly uniquely* identify the object (and more descriptive), no matter what scientific language you speak of.
Sometimes I just hope that astronomers just quit being catalogue makers and act more
When Worlds Collide (Score:2)
In Related News . . . (Score:4, Funny)
Wait, I saw this episode... (Score:4, Funny)
Fun for the kids~! (Score:2, Interesting)
At the risk of being modded OT, this article reminded me of an awesome little trick an old physics teacher did to help us visualize how we got from the big bang to planet earth.
Take a small bowl, fill it with water. Then, add a handfull of dark sand. Let the sand sort of float in "space" for a bit, moving the water enough to keep everything floating.
Now, to "play God", simply twirl the water counter-clockwise (or vice versa if you live under the equator) and remove your hand. Behold: your universe of sa
Re:Fun for the kids~! (Score:2)
Re:Fun for the kids~! (Score:1)
hehe (Score:1)
The Planemo Effect (Score:2, Informative)
Planet? Star? Planetoid? ... Junk? (Score:1)
Or maybe I'm just a jerk today.
Planemos? (Score:2, Funny)
Must not have been any Spaniards at that observatory... at least none with any clout.
Unless there are and they're planning [wordreference.com] to name it something else later.
Planemos as a word (Score:2)
There's no word planemos in Spanish. A similar one could be planeamos, meaning "we plan" or "we planned".
--
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It has to be asked? (Score:2, Offtopic)
Re:It has to be asked? (Score:2)
try two at my sig... www.mymegastores.com -- your solution for getting out of your parent's basement
Re:It has to be asked? (Score:2)
That's why there aren't any trinary stars (where all three are of similar mass) - AFAIK.
duh (Score:2)
Stuff coalesces. Some is dense, some is not. that which is suficiently dense makes stellar systems. That which is mot does not. Pretty simple, I think.
(IAAA - 'I am an astronomer')
wrong debate? (Score:1)
Hmm, and I was wondering if the finding should start debate on what makes a star or stellar object, silly me
Oblig. MIB quote (Score:2)
In addition to presenting astronomers with a new group of objects to study, the finding also deepens the debate over what makes a planet.
"You humans, when're you gonna learn that size doesn't matter? Just 'cause something's important doesn't mean it's not very, very small."
They are planets. (Score:2)
Subject (Score:2)
Important question (Score:2)
Re:vomits at lovely new slashdot layout (Score:1, Informative)
Crap is defined as:
1. fonts way too small
2. words overlapping each other
Re:vomits at lovely new slashdot layout (Score:1, Offtopic)
Safari (latest) on 10.4 (latest) is fine.
Words overlapping each other does sound like a Firefox rendering problem.
Not sold completely on the
Are you reading this random comment, Steve?
Re:vomits at lovely new slashdot layout (Score:1, Flamebait)
Re:vomits at lovely new slashdot layout (Score:1, Offtopic)
The only problem I've had is that the story got bumped down about half a page length once, but didn't cause overlapping.
Re:vomits at lovely new slashdot layout (Score:1, Offtopic)
Looks much better on Linux (Score:1, Offtopic)
It looks better with Firefox under Linux then Windows. I wonder if I can adjust firefox's fonts with just one domain?
Re:vomits at lovely new slashdot layout (Score:1, Offtopic)
Re:vomits at lovely new slashdot layout (Score:1)
Re:slashdot-shinyfix.css v.001 (5 Jun 2006) (Score:1)
PWNED
Re:space.com is the Fox News of the Internet (Score:2)
The rule of thumb I give anyone who comments on news channels they hate is this:
If 50%
Re:space.com is the Fox News of the Internet (Score:2)
> it unless you aren't liberal.
Liberals will argue that liberal news is not liberal and conservatives will argue that conservative news is not conservative. Both are wrong. Meanwhile, both miss the fact that both liberal and conservative news often just get the facts wrong.
> If 50% of what you hear doesn't fit into "I don't care" or "that pisses me off", you're
> watching a news channel biased to your own op
Re:space.com is the Fox News of the Internet (Score:2)
When a media source (liberal or conservative) tries to cram "news" down your throat, you only get the newscaster's POV.