Final answer:
Earth was formed about 4.5 to 4.6 billion years ago from a stardust cloud. As it cooled, Earth's atmosphere and oceans were created from volcanic activity and comet impacts. We are fundamentally made of stardust, with elements originating from stars and supernovae.
Step-by-step explanation:
Overview of Earth's Formation
Earth formed approximately 4.5 to 4.6 billion years ago from a rotating cloud of stardust, consisting primarily of hydrogen and helium. Through the processes driven by the laws of physics, particles within the dust cloud began to clump together, forming a larger mass that became hot and molten due to collisions and gravitational compression.
Over time, the Earth cooled, developing a solid crust, and through a combination of volcanic outgassing and impacts from comets and asteroids, Earth's atmosphere and oceans formed.
Formation of Earth's Atmosphere and Oceans
The Earth's early atmosphere likely formed through volcanic activity, releasing gases from the planet's interior, and through the contributions from impacts by comets and asteroids. These events eventually allowed for the accumulation of water vapor, which cooled and condensed to form the oceans. This period was pivotal for the development of conditions suitable for the emergence of life.
Earth's Place in the Cosmos
Looking at the larger cosmic picture, Earth and all life are comprised of elements that were forged in the hearts of stars and spread throughout the galaxy by supernovae. This realization connects us to the universe in a profound way, as we are made of the very stardust that comprises the cosmos.