Write a report on the physics and nature of the Sun with a total length of 3 pages. Please use as font "Times New Roman." Start with a single-spaced Abstract, about 3-5 lines long, which summarizes the key points of the report. Include information on the Sun's composition, structure, and energy production. Discuss its role in the solar system and its impact on Earth. Provide examples of solar phenomena and their effects. Use scientific evidence and references to support your claims.