Climb Aboard! Explore how the sun was formed! Investigate spots, flares, and solar wind! Meet early astronomers working to understand the sun! Examine the sun, the moon, Earth, and gravity! Learn about solar observatories! See an infographic showing the sun's layers! Did You Know? fact boxes and a Guidebook of facts about the sun complete your journey. Aligned to Common Core standards and correlated to state standards. Checkerboard Library is an imprint of Abdo Publishing, a division of ABDO.