This is the start of a series that introduces different tools in Adobe Illustrator. If you like to create the illustration in How did the World Come About, you will be using these tools!
1. Rectangle and Ellipse tools
2. Stroke and Fill
3. Color swatch, Gradient swatch (Radial), including the gradient sliders (use yellow and orange for the sun and only orange for the moon; adjust the gradient slider for the effect you want)
4. Pencil tool for the continents
Most Talked About Clues (blog posts)