So stoney and metalic asteroids formed from dust and gas condensed from plasma. You would think they would be fluffy, dust piles, unless they had been part of a body large enough for its own gravity to melt it--large enough to form a sphere? Yet we're told that Sol's asteroid belt was never part of a larger body, whether torn apart by Jupiter's gravity or smashed to bits by an impact. But aren't many of them quite dense, even solid metals? How does that happen in vacuum, without enough mass in one place to at least melt a core?