Hayat Ashraf

The origin of the Earth is a topic of scientific inquiry and is part of the field of study known as cosmogony. While our understanding of the Earth's origin continues to evolve as new discoveries are made, the prevailing scientific theory is known as the "nebular hypothesis." According to the nebular hypothesis, the Earth and the rest of the solar system formed approximately 4.6 billion years ago from a giant rotating cloud of gas and dust called the solar nebula. This nebula was composed mainly of hydrogen, helium, and small amounts of heavier elements. The nebula began to collapse under its own gravity, leading to the formation of a spinning disk-shaped structure called the protoplanetary disk. Within the protoplanetary disk, particles began to collide and stick together, forming larger and larger objects known as planetesimals. These planetesimals further collided and merged to create protoplanets—large bodies that eventually became the planets in our solar system. The...