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Strange Mini Solar System Found
starexplorer writes "In 1990, Penn State's Alex Wolszczan found the first exoplanets. But he never got much credit from mainstream researchers, because his planets (3
of them, roughly Earth-sized) orbit pulsars and hold no chance for harboring life. Now he's found a 4th object on the outskirts of the system, SPACE.com is reporting. Call it a planet, call it an asteroid, Wolszczan says, but call the setup a dark, eerie twin of the inner half of our solar system. Also in the same story, news of a brown dwarf just 15 times the mass of Jupiter that has a planet-making disk of stuff around it. Together, more problems for astronomers, who still don't have a basic
definition for the word planet or a firm idea of what separates planets from stars."
I think They Might be Giants defined what it was to be a star fairly well.
"The sun is a mass of incandescent gas
a giagantic nuclear furnace..."
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How can this professor not be considered mainstream?
He's on the faculty at Penn State! Sounds like he must have ticked off the wrong people at some point in his career. Maybe he needs to hire a PR person.
I would say that finding a planet orbiting any star would be significant news, regardless of whether said planet might harbor life.
"Lack of technical competence coupled with the arrogance of power, as usual, leads to no good end."
semantics seperates planets from stars from asteroids... Our language, not reality...
Space. Quite a bit of it, I hope.
Oh, you meant what criteria separates planets from stars?
Well, I definitely would much rather live on one than the other. Is that a good definition?
As far as a definition I found this:
"Working Group on Extrasolar Planets
Defintion of a "Planet"
POSITION STATEMENT ON THE DEFINITION OF A "PLANET"
WORKING GROUP ON EXTRASOLAR PLANETS (WGESP) OF THE INTERNATIONAL ASTRONOMICAL UNION
Created: February 28, 2001
Last Modified: February 28, 2003
Rather than try to construct a detailed definition of a planet which is designed to cover all future possibilities, the WGESP has agreed to restrict itself to developing a working definition applicable to the cases where there already are claimed detections, e.g., the radial velocity surveys of companions to (mostly) solar-type stars, and the imaging surveys for free-floating objects in young star clusters. As new claims are made in the future, the WGESP will weigh their individual merits and circumstances, and will try to fit the new objects into the WGESP definition of a "planet", revising this definition as necessary. This is a gradualist approach with an evolving definition, guided by the observations that will decide all in the end.
Emphasizing again that this is only a working definition, subject to change as we learn more about the census of low-mass companions, the WGESP has agreed to the following statements:
1) Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars or stellar remnants are "planets" (no matter how they formed). The minimum mass/size required for an extrasolar object to be considered a planet should be the same as that used in our Solar System.
2) Substellar objects with true masses above the limiting mass for thermonuclear fusion of deuterium are "brown dwarfs", no matter how they formed nor where they are located.
3) Free-floating objects in young star clusters with masses below the limiting mass for thermonuclear fusion of deuterium are not "planets", but are "sub-brown dwarfs" (or whatever name is most appropriate).
These statements are a compromise between definitions based purely on the deuterium-burning mass or on the formation mechanism, and as such do not fully satisfy anyone on the WGESP. However, the WGESP agrees that these statements constitute the basis for a reasonable working definition of a "planet" at this time. We can expect this definition to evolve as our knowledge improves."
It looks like this is as close as we're going to get.
"Lack of technical competence coupled with the arrogance of power, as usual, leads to no good end."
Please, "African American little person with a weight problem" is a little more appropriate and a lot less offensive, don't you think? Sheesh.
Go figure.
Logic, macros, and more
At least according to Wikipedia
Scientifically, stars are defined as self-gravitating spheres of plasma in hydrostatic equilibrium, which generate their own energy through the process of nuclear fusion.
Using this simple definition, it seems to apply to most stars out there? Correct me if I'm wrong or if the definition provided isn't accurate enough.
A planet:
-is a non-fusor
-has sufficient mass to be roughly spherical due to gravity
-orbits a fusor
-isn't already referred to as any other type of object by convention
-isn't associated through orbital composition or other general characteristics with another general group of non-planet objects (i.e. Vesta, though spherical, is associated with other objects known as asteroids, which are not massive enough to be spherical, and are therefore not planets. Vesta also is not a planet, because of the previous rule. It is by convention known as an asteroid, therefore it's not a planet.)
My source for this definition is myself, and I deem it sufficient for sparking a major discussion, and possibly for other things as well.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
"who still don't have a basic definition for the word planet or a firm idea of what separates planets from stars."
One is on fire and one isn't.
Now hand over my research grant.
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insert sig here,here, and here
Acutally there are only two forms of life possible.
According to whom?
The only life we can be certain of is our own. Even then I sometimes wonder if I really exist. I guess I must because I am posting this, or am I?
problems for astronomers, who still don't have a basic definition for the word planet or a firm idea of what separates planets from stars.
It's not as sexy as having a word like "planet", but all this confusion could be eliminated with a basic classification system that took into account distinguishing characteristics besides just it's mass.
As an example, one could define these objects through two primary attributes: The body's mass and the mass of that which it orbits. As I don't have exact mass data at hand, this example will use the following over-simplifications:
S = Solar Mass
G = Gas Giant Mass
R = Rock Planet Mass
M = Minor Mass ( appx Phobos to Pluto )
A = Asteroid Mass
D = Debrit ( 1m or smaller )
Of course, the real system would use exact scientific measurments rather than these crude examples.
Earth = SR ( Rock Planet Mass orbiting a Solar Mass )
Jupiter = SG ( Gas Giant Mass orbiting a Solar Mass )
Pluto = SM ( Minor Mass orbiting a Solar Mass )
Titan = GR ( Rock Planet Mass orbiting a Gas Giant Mass )
etc
etc
You could even create a symbol to represent the galactic center, which could be used in relation to stars and other free roaming bodies. Binary stars can be represented using SS, since they're orbiting each other.
Anyway, the point is that you can not come up with solid definitions of these bodies on mass alone. Take into account other major factors as this example does.
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote.
planet n.
Big lump of stuff, roundish, spinning a bit, usually orbiting a, um, star thingy. Might have aliens on, but probably not. Probably.