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4. Our Solar System & Earth
Billowing clouds of matter spun around and around our young Sun, gradually forming just about everything in our Solar System – from meteors and asteroids to all the planets and moons. One planet in particular would enable the creation of even more remarkable complexity.
All content in “4. Our Solar System & Earth”

4.0 Earth and the solar system

Earth formed from the leftovers of the Sun accumulating over time. Despite its violent and unstable beginning, Earth slowly (very, very slowly) became the world we know today.

4.1 How our solar system formed

Chemically rich clouds of tasty leftover matter orbited our newly formed Sun. Chunks of debris collided and smashed into each other, eventually creating our Earth and Solar System.

4.2 What was the young earth like?

As giant hunks of rock, metal, and ice slammed into the Earth’s surface, it became a planet with three layers. The interplay between the layers resulted in the Earth as we know it.

4.3 Why is plate tectonics important?

Towering mountains and trembling earthquakes, the surface of our Earth is constantly in motion. Plate tectonics is responsible for the shape and position of our land.

4.4 Ways of knowing: Our solar system

The history of our planet – along with clues about its future – is written in rock record. Rock detectives (geologists) study these clues and often observe Earth's changes firsthand.

Practice and feedback

Test your Unit 4 knowledge and skills! Investigate when and why people accept a theory, and take the Unit 4 quiz and glossary challenge.