The Sun

Image Courtesy of NASA

 The August 31, 2012 coronal mass ejection of the Sun shown in four different extreme ultraviolet wavelengths

The most important star to Earth is the Sun. Without the Sun’s exact location, mass, and luminosity, life may not have ever evolved on Earth. Astronomers study the Sun to gain an understanding of its role in the Solar System and its interactions with planet Earth. They want to know how the Sun works and why and how it changes over time.

While the Sun is just a medium-sized star, it is by far the most massive body in the entire solar system. Scientists estimate that 99% of the mass of the solar system is made up of the Sun, while the remaining 1% makes up all of the planets, asteroids, moons, and other objects combined.  The Sun is about midway through its life cycle as a star, and it is actively changing. In this topic, you will explore the parts of the Sun, the process by which the Sun produces energy, and the different types of solar activity.

Essential Questions

• What are the different parts of the Sun?
• How and where does nuclear fusion occur?
• What are the characteristics and effects of sunspots, solar flares, solar prominences, and auroras?