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Are Small Rocky Worlds Naked Gas Giants?
astroengine writes "The 'core accretion' model for planetary creation has been challenged (or, at least, modified) by a new theory from University of Leicester astrophysicists Seung-Hoon Cha and Sergei Nayakshin (abstract). Rather than small rocky worlds being built 'bottom-up' (i.e. the size of a planet depends on the amount of material available), perhaps they were once the cores of massive gas giant planets that had their thick atmospheres stripped after drifting too close to their parent stars? This 'top-down' mechanism may also help explain how smaller worlds were formed far from their stars only to drift inward toward the habitable zone."
I imagine this excludes Earth, but if not it would explain a lot of the smells.
I should have been a girl, with the way I can dance... my moves are amazing!
I've had this idea before. Thought that's what happened to Pluto, when I was was in 3rd grade. I don't see anyone nominating me for a Nobel prize!
For a long time the only planets we found were 'hot Jupiters'. Jupiter sized planets very close to their star (inside Mercury's orbit).
Why weren't these planets stripped of their atmosphere?
Your crust is showing. Slut.
How does this square with the idea that gas giants have materials like metallic hydrogen at their cores? I can see how accretion can occur without the necessity for a rocky core, and I can see how it would occur with one.
There isn't necessarily a dilemma here as the theory still can be consistent for both results, in terms of rocky "terrestrial" bodies being naked gas giants and "traditional" gas giants still having a metallic hydrogen core.
Planets like Jupiter and Saturn, while certainly the bulk of their current mass is Hydrogen and Helium, they do have other elements that comprise their structure and more than likely you would find at the core of these planets a "rocky" core that would include Iron, Nickle, and other elements that would be more identifiable with what we have here on the Earth. The question would be how large would that tiny "rocky" core would be if you stripped off the outer gaseous layers.
The problem with this theory is mainly how you go about stripping off that outer layer. The presumption here is that objects close in to a star like the Earth, Mars, and Venus are at the moment would have had this outer "shell" being stripped off at some point in the distant past as the Solar System was being formed.
As this calculation for CoRoT-2b indicates, at 6M tons per second, a hot super-Jupiter would need more than 39B years (~3x the age of the universes) to be "blown/boiled away". Jupiter is ~1/3 the mass of CoRoT-2b, so at 6MT/s, it would last 13B years. The rate of loss of atmosphere would have to be at least a factor of 10 greater than on CoRoT-2b, or greater than 60MT/s just for a Jupiter mass planet to to reach an Earth mass core in 1.3B years. Our solar system is estimated to be ~5B years old and that Earth and Mars both appear to have been rocky for more than 2B years, so 1.3B years to blow off an atmosphere seems to be a generous estimate of quickly it must have happened.
Given that our sun is only converting ~600M tons/sec of hydrogen into ~594M tons of helium, a net loss of 6MT/s, therefore a Jupiter mass planet would need to be receiving a enough of the solar radiation to blow off 60MT/s. Yes, E=mc^2, and c^2 is large, but you're still talking about a lot of mass to move out of notable gravity well (first out of the Sun's gravity well, then move more mass out of Jupiter's gravity well). If jupiter were in earth's orbit, would it receive enough solar radiation to lose 60MT/s? Not from solar wind, the total solar wind mass is ~1.85MT/s. even if all 1.8MT were directed at Jupiter and Jupiter had no magnetopause to protect it from the solar wind, 1.8MT/s would not strip 60MT/s of atmosphere. So you have to come up with a theory where the EM radiation causes the the planet to eject it's own atmosphere, which is still going to be virtually impossible.
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Gas giants are wannabe stars. They are Pauly Shores of the night skies.
You can't handle the truth.
They can't really prove there is a distant planet revolving around a distant world.
You seem to have bought the 'distant world' theory, you're this close in believing the earth isn't flat. Do your parents know this?
"I'm not much interested in interoperability. I want substitutability. I want to be able to throw your software out."
The Earth surrounded by Oxygen gas (and other gases) in the atmosphere, the only difference to us is that our eyes have evolved to see through the wavelength of oxygen making it appear 'invisible', but from the hypothetical alien point of view, an alien looking at earth might not have the eyes to see through the Oxygen and it would look like any other gassy planet from their perspective.
Maybe the technology can be developed to look through the gasses of other planets to see inside in the same way we can see though oxygen.
Sorry if there are any scientific errors in my theory, I'm not an expert, but unlike most the other posters on Slashdot, I don't even pretend to be one.
Eureka moment....here is what I believe, if the clouds are like the cocoon of a moth, helping keep it safe until it transforms, then you could almost say that the cloud is there for a reason, and that the planet is now morphing into a solid planet ready for life. This would imply that the gas is great vs. anything damaging to a planet while forming....such as cosmic or gamma rays, solar winds, UV rays etc...whatever that might be ....we can also deduce that if the gas planets are the precursors to
formed planets...then we can assume there is an evolutionary path that forces the gas inside to condense while the gas outside stays there for protection...leading to believe that there are 2 types of gas...one for creation of , and one for defense....
Now that we know this, I think if we were to use that same information and look into the defense properties of that second gas, in order to define what it is made up of, and maybe replicate that someway for our development of mars, in essence helping the mars rock to become habitable (again or for the first time?) ...
it might help us create a second rock that can hold human life.