ive read on wikipedia that mercury has an iron core. I also read (in a different article) that certain kind of small stars (red dwarfs i think) will eventually cool down as they start fusing the heavier elements upto iron and the end up with iron cores. Is there a connection here? Stars are supposed to come from large gas clouds (right?) where did the gas cloud originate? DId the cloud simply form from a 'burnt out' star? SO then other materials just happening to pass by contributed to the cloud? WHen or why did planets form then? Wouldnt a ball of gas prefer to stay in its state rather than solidify into a terrestrial planet like earth or venus?