"The Geologic Time Scale"

The Geologic Time Scale is a way scientists organize Earth's history into blocks based on major events like the appearance of new species, mass extinctions, and changes in Earth's environment. It divides Earth's 4.6-billion-year history into eons, eras, periods, epochs, and ages, with each representing significant geological or biological milestones. This timeline helps us understand how life and the planet have evolved over time. It’s built from studying rocks, fossils, and the Earth's physical features, providing a structured way to track the planet's dynamic history across billions of years.