Had Venus developed life, it might have evolved to a life-friendly planet. Most of the planets revolve around the sun in a orbit with an axis parallel to each other, as do their rotations. The Moon was formed by a large impactor Meteorites and asteroids are from the asteroid belt, between the Earth and Jupiter. Perturbations cause them to fall into an Earth-crossing orbit. Apollo objects are large meteorites.
Comets are early-formed 'ice balls', with eccentric orbits.
Coalescence of silicate material. During the gravitational compression, there was heating. The heating caused the segregation of the Earth s core, which concentrated iron. Caused melting or iron-nickel and formation of core. The falling of this iron core would cause a heating increase of over 2000 C. Planetary differentiation is the most significant event in the history of the Earth.