The Sun

#1 The sun is actually the closest star to the Earth. Compared to other stars, the sun is a Small to below average sized star.

#2 All stars get their energy by the fusion process. Fusion is the combining of smaller elements to form heavier elements. In the case of the sun and most other stars, the fusion process involves the combining of atoms of hydrogen to form helium and in the process huge amounts of energy are given off.

Fusion of H to make He

#3 E is energy M is mass C2 is the speed of light squared A lot of this process was explained by Albert Einstein in his famous equation: E = MC2, E is energy M is mass C2 is the speed of light squared Speed of light is 300,000 km/sec

#4 Astronomers have never actually seen the interior of the sun for obvious reasons, but there are theories as to how the sun is structured First astronomers estimate that the temperatures in the sun’s core may approach 15,600,000 degrees C

More #4 The visible surface of the sun is called the photosphere and it is estimated to be about 6,000 degrees C The inner layer of the sun’s atmosphere is called the chromosphere and it is about 20,000 degrees C

#5 The very thin outermost layer of the sun’s atmosphere is called the corona. Even though the corona is much less bright than the photosphere, it’s temperature is estimated to be about 1-3 million degrees C.

#6 The sun is about 150,000,000 km from the Earth. This varies from season to season a little. For convenience sake, this average distance is called an astronomical unit (AU)

#7 Dark spots on the sun’s photosphere are called sunspots. These sunspots are like storms on the surface of the sun. Another feature of the sun is the solar wind. The solar wind is actually a steady stream of protons and electrons and stream out of the sun in all directions.

More #7 Solar wind can be deflected by the Earth’s magnetic field. We can view this solar wind on the Earth but we call it an aurora, or the Northern Lights (aurora borealis) In the southern hemisphere the same phenomenon is called aurora australis

#8 The Solar System is heliocentric. That means that it is sun centered. The 9 planets of our solar system orbit the sun in a counter clockwise direction. ( If viewed from above)

More #8 Hundreds of years ago, however, it was widely accepted that the Earth was at the center of the rotation of the sun, stars and planets. (INCORRECT!!!) This is referred to as the “geocentric” model. (Earth centered) And it is 100% incorrect. My how times have changed. An astronomer by the name of Copernicus was the first to propose the heliocentric model.

#9 The model of the solar system really changed with the observation of “wandering stars” These “wandering stars” actually turned out to be the planets. And of course the Earth was one of these.

#10 One of the hang-ups to the heliocentric model was the lack of a theory as to why the planets stayed in orbit. Why didn’t they fly off into space?

More #10 Enter Sir Isaac Newton. He explained the Law of Universal Gravitation. (The Law of Gravity) In a nutshell, Newton explained that anything that has mass has gravity.

More #10 The force of gravity between any 2 objects depends upon 2 things: The mass of each object and the distance between the objects. The more mass an object has, the more gravity is has, And the closer 2 objects are, the stronger the force of gravity is between them.

The End!!!