This sounds reasonable. If the gas prevents the agglomeration of dust (I am not sure about this, though), it would be a great explanation of why rocky planets can only form in protoplanetary discs around stars.
I do not understand how this gaseous envelope is formed around the dust...
So the density of dust is too low if there is not strong attractor like a star to have a sufficiently large number of collisions of dust particles to form a planet?
Sorry for my maybe stupid questions: do we know anything about the density of interstellar dust clouds?
Dust originates from...
After googling for many hours I am still not understanding why the formation of rocky planets shall be restricted to protoplanetary discs.
Why can't they form from dustclouds far away from any star? Agglomeration should still happen over time. Jeans criterium should not play a role since it is...