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| WASP-18b orbits its star faster than 1 earth day |
Now they have come up with the disk instability model, This idea is even sillier. It posits the notion that clumps within a disk rapidly condense into a planet. This theory was come up with because of the discovery of hot Jupiters which undermined their first theory. So they made up another theory.
Observations in IC348 helped lead to this newer accretion model since the dust depletion in 9 of the disks was much to rapid. As reported in the magazine New Scientist ---
"Exoplanet systems around other stars are surprisingly flat compared with our own,” reporter Jeff Hecht wrote. “The discovery means that the solar system must have had a far more colourful history than many of its counterparts and is forcing astronomers to rethink their ideas about the way planetary systems form.”
Erik Asphaug explains in the Annual Review how this process works...
"The first stage of planetary accretion is among the most complex studies in astrophysics. As they accumulate, planetesimals are entrained within a disk that undergoes violent shocks and propagates gravitational waves and eddies. Magneto-rotational instabilities might lead to high turbulent viscosities, which lead to radial transport and vertical mixing and viscous spreading. Solid particles settle to the mid-plane, increasing the density so that planetesimals might eventually coagulate. Electric discharge and impact heating take place sporadically. Outside this mid-plane the young sun blasts the gas and sweeps away small material. Drag against the gas disk forces meter-sized boulders to spiral in from the planet-forming region.When it comes to stars & planets...he made the stars also. Genesis 1:16
The chemical environment, too, is grossly out of equilibrium. The disk experiences a wide range of temperatures and pressures and oxidation states, with sharp gradients in time and space. Where the disk is optically thick, it can remain hot for thousands of years; where it is thin, it can cool in days or even minutes. Thermodynamic energy is available from solar heating, shock heating (by impacting globules striking the disk, by disk planetesimals colliding with one another, and by shocks in the gas), compression heating (adiabatic work), and radionuclide decay. This energy is transported radiatively and convectively. "
A Rebuttle to Aspaugh".. primary accretion: that’s the heart of the matter. In the primary stage of planet building, the tiny dust grains need to accrete, or stick to one another. Only when a planetesimal gets up to kilometer size or more in diameter will its self-gravity pull more material in. Little particles lack the gravitational potential to grow on their own. They’ve got to link up by other mechanisms while in the shooting gallery, with all that turbulence, wind, heating, cooling, colliding and electrical activity tending to disrupt them. Can this work? "