It divides off the Earth and this colliding rough protoplanet into many different particles and then the evolution of each particle is tracked through the course of the impact.
Scientists call Vesta and Ceres " protoplanets." Mr. Rayman says they were in the process of becoming full-size planets when, in his words, " their growth was terminated."
Third—a period millions of years later, when these primordial particles began to clump together into protoplanets, while others—such as those that formed Aguas Zarcas —lay low in the cold void beyond Jupiter.
Ceres is known as a protoplanet, and that means that scientists believe it was in the process of forming, like a full-pledged planet, and its formation was suddenly halted, likely by the tremendous gravity of Jupiter.