Video · Tides: Crash Course Astronomy #8 TwitterShare on Facebook643 967 875 views Crash Course - March 5, 2015 Science Crash Course Gravity More Videos Where do rocks come from?: Crash Course Geology #6 Science · 9 hours ago How Do Minerals Form?: Crash Course Geology #5 Science · 1 week ago How Do Minerals Form?: Crash Course Geology #5 Science · 1 week ago What’s at the center of the earth?: Crash Course Geology #4 Science · 2 weeks ago Earth’s Crust and Mantle Explained: Crash Course Geology #3 Science · April 23, 2026 Earth’s Crust and Mantle Explained: Crash Course Geology #3 Science · April 23, 2026 How did Earth form?: Crash Course Geology #2 Science · April 16, 2026 Intro to Geology: Crash Course Geology #1 Science · April 9, 2026