martes, 6 de diciembre de 2011

THE SUN IN THE MIDDLE

Everything in the Solar System orbits around the Sun. It's mass is greater than all of the other planets combined. Even though the Sun is huge, it is small when compared to other stars in the galaxy. Even though it is smaller, the Sun provides all of the light for the Solar System. As far as astronomers are concerned, our Sun is named Sol. The entire group of Sun and planets is called the Solar System. If another star were named Andros, that system would be named the Androsian System.


THE SUN'S CORE

There is a core to the Sun as there are in planets. Stars are different because most of that central mass is made of tons and tons of hydrogen (H) and helium (He). The hydrogen is constantly involved in the fusion reactions, which produce extreme amounts of energy (light, heat, radio waves). Did you know that our Sun used to be hotter? Astronomers now classify it as a G2 star. It is middle-aged and starting to cool and die. Don't worry. It's going to take millions of years for it to burn out. For example, a G5 star is very old and close to death.

LAYERS OF MATERIALS

The Sun has different layers in its atmosphere, just like the Earth. Don't get excited, you aren't going to be able to breathe on the Sun. The layers of the atmosphere are huge, swirling masses of plasma at extremely high temperatures. Surrounding the core is a radiative level of plasma. Reactions happen in that layer and churn/stir the next layer, the convective layer. Large amounts of interaction occur in the convective layer. It's constantly spinning the way storms spin on Earth. The outer layer of the Sun's atmosphere is the photosphere. When scientists use special telescopes to look at the Sun, this is the layer they can see.

THE SUN'S INFLUENCE

Everything on Earth is affected by the Sun. The Earth's orientation to the Sun creates the seasons of the year. When your hemisphere of Earth is directed away from the Sun, it is winter. When your hemisphere is pointed closer to the Sun, it is summer. So when you're in the Northern Hemisphere and it's summer, kids in Australia might be skiing. As you learn more about the other planets in the Solar System, you will discover that the same idea works for most of them.

The Sun's energy is spread around the planet, but is focused on or near the equator. That centerline of the planet is where you will find long sunny days, very little seasonal change, and the warmest ocean waters. From the equatorial regions, energy moves north and south as it circulates around the planet. That circulation can happen in the atmosphere or the oceans.

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