This document provides information about the sun in the form of a classroom lesson on earth science. It begins with the day's learning goals which are the characteristics, composition, and phenomena of the sun. Several facts are then listed, such as the sun being 109 times the radius of Earth and having an average surface temperature of 5700°C. The interior and atmospheric layers of the sun are described along with features like sunspots. The document explains that the sun is made primarily of hydrogen and helium created through nuclear fusion, and discusses how spectroscopy is used to determine its composition. It concludes by addressing whether the sun will explode and engulf Earth.