Tau.Neutrino said:
Planetary formation
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Witty Rejoinder said:
Researchers Revise Recipe for Building a Rocky Planet Like Earth
Over the past decade, researchers have completely rewritten the story of how gas giants such as Jupiter and Saturn form. They’re now debating whether the same process might hold for Earth.
https://www.quantamagazine.org/scientists-debate-if-cosmic-pebbles-create-rocky-planets-like-earth-20211103
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How does this sound?
Hydrogen gas cloud along with rocks, pebbles and other elements collapses millions of years after a large star explosion.
The collapse will form an accretion disk with a core.
The core of the hydrogen gas cloud collapse is the sun, further out in the spinning gas cloud is where the planets slowly form as the gas cloud starts to collapse forming an accretion disk.
This is a flat disk where the star and planets will form after the gas cloud starts to spiral around the core sweeping most of the mass of gas and rocks into bands, containing either a developing planet collecting mass or creating empty space between the planets.
The spiralling bands develop into spherical shapes that move around a central core are the birth of planets developing over billions of years, they move around a central core which will become a star.
The gas, pebbles and rocks containing metals and other elements created from a previous star explosion would have had a cool start in the beginning of the hydrogen gas cloud collapse, then would be slowly heated up as the cloud collapses further becoming an accretion disk, with everything being heated up within a fast rotating spiral creating bands of hot material, making the rocks and pebbles sticky and oily like, attracting dust and gas while gravity pulls them all into a spherical shape. All this starts beginning in the infra red, then heats up further creating a black body radiation accretion disk, before becoming brighter. The accretion disk eventually develops into the spiralling bands each going on to become a spherical planet giving off black body radiation which cools down again over billions of years as they orbit around their star.
Does that sound right?
> Over the past decade, researchers have completely rewritten the story of how gas giants such as Jupiter and Saturn form
What!? No they haven’t, so far as I know. Neptune perhaps, but not Jupiter or Saturn.
> Hydrogen gas cloud along with rocks, pebbles and other elements collapses millions of years after a large star explosion.
Yes. The shock wave causes collapse due to gravitational instability.
> The collapse will form an accretion disk with a core.
Yes.
> The core of the hydrogen gas cloud collapse is the sun, further out in the spinning gas cloud is where the planets slowly form as the gas cloud starts to collapse forming an accretion disk.
Yes.
> This is a flat disk where the star and planets will form after the gas cloud starts to spiral around the core sweeping most of the mass of gas and rocks into bands, containing either a developing planet collecting mass or creating empty space between the planets.
Actually, that one I’ve never heard of, but it makes more sense than the other mechanisms I have heard of.
> The spiralling bands develop into spherical shapes that move around a central core are the birth of planets developing over billions of years, they move around a central core which will become a star.
Yes.
> The gas, pebbles and rocks containing metals and other elements created from a previous star explosion would have had a cool start in the beginning of the hydrogen gas cloud collapse, then would be slowly heated up as the cloud collapses further becoming an accretion disk, with everything being heated up within a fast rotating spiral creating bands of hot material, making the rocks and pebbles sticky and oily like, attracting dust and gas while gravity pulls them all into a spherical shape. All this starts beginning in the infra red, then heats up further creating a black body radiation accretion disk, before becoming brighter. The accretion disk eventually develops into the spiralling bands each going on to become a spherical planet giving off black body radiation which cools down again over billions of years as they orbit around their star.
Basically yes. I particularly like your “making the rocks and pebbles sticky and oily like” which is one I hadn’t heard of before. And if true would solve a long-standing problem of how impacts resulted in growth rather than fragmentation. If the rocks and pubbles weren’t sticky then collisions would cause fragmentation rather than coalescence. Chondrules did have a liquid-like outer layer which resulted in what are known as “Wark-Lovering” bands.
The hydrogen gas between the particles slows the particles down so that they hit one another relatively slowly, which is necessary in early stages of rocky planet formation. This hydrogen gas is ejected from the solar system by UV light from the newly formed Sun. That loss of hydrogen gas happened before the planets were their final size, eg. before the collision that formed the Moon.