The Earth’s origin dates back 4.54 billion years, during which the lithosphere, atmosphere, and hydrosphere were formed. This process also gave rise to life on Earth around 3.5 billion years ago. The widely accepted theory for the formation of Earth is the nebular hypothesis, which suggests that the planet formed from a massive cloud primarily composed of hydrogen and helium. As the cloud contracted, rotated, and cooled, it gave rise to small particles that gradually clumped together over millions of years to form the Earth about 4.5 billion years ago. Understanding the origin of the Earth is a crucial concept in Geomorphology, which forms a significant part of the Geography Optional for UPSC exams.

Topic NoTopic Name
Topic 1Gaseous hypothesis of Kant
Topic 2Nebular hypothesis of Laplace
Topic 3Planetesimal hypothesis of Chamberlin
Topic 4Jean and Jeffery’s tidal theory
Topic 5Russel’s binary Star Hypothesis
Topic 6Hoyle’s supernova hypothesis
Topic 7Schmidt’s interstellar hypothesis
Topic 8Big bang theory