How much of the solar system had to be formed in order for a planet like the earth to establish a stable orbit around the sun? Could something like the earth have an orbit around the sun if the solar system had no other planets and moons to counter the sun’s gravitational attraction? Would the earth crash into the sun or fly off into space if it was by itself?
Also, if the planets were formed by space dust from the Big Bang accumulating together by gravity, what caused the original gravitational attraction that was needed to form each planet’s core? What kept the dust from being siphoned off by larger objects that already existed?