Cookie Policy

Our website uses cookies to understand content and feature usage to drive site improvements over time. To learn more, review our Terms of Use and Privacy Policy.

Threshold 4: Earth & the Solar System (2:49)

Key Ideas

As this video progresses, key ideas will be introduced to invoke discussion.

Key Ideas

Think about the following questions as you watch the video


  1. 01:28 What enabled planets to form?
  2. 02:15 When did the Earth form?