by Mark Dykeman

Created on: July 30, 2007   Last Updated: March 10, 2010

Our Sun, the star that is closest to our planet, is the major source of light and life in our solar system. The Sun, or Sol as it is sometimes called, warms the Earth's surface and keeps the planets, asteroids, and comets in orbit. The Earth would be a frozen ball of ice and rock without the Sun's radiant power. Here are ten facts about our Sun for your education and entertainment - plus one bonus fact!

1. The Sun's mass represents 99.8% of the mass of our entire solar system, including all planets, moons, asteroids, comets, and other matter.

2. The Sun has a diameter of 1.39 million kilometers. You could fit 1.3 million Earths inside the Sun!

3. The Sun orbits the Milky Way at a distance of approximately 26,000 light-years from the center of the galaxy.

4. The Sun revolves around the Milky Way galaxy every 225 to 250 million years.

5. The Sun is believed to be in the top 10% of mass compared to all of the stars in the Milky Way galaxy, larger than 90% of the other stars. It's also brighter than 85% of the stars in our galaxy.

6. The Sun actually emits white light, not yellow. Earth's atmosphere makes the Sun seem yellow as the light rays are filtered through the layers of the atmosphere.

7. Our Sun is entering its middle age, in human terms. Scientists estimate that the Sun is about 4.5 billion years old. The Sun is expected to stay active (i.e. continue to undergo fusion at its core) for at least another 4.5 billion years. It could last a total of 10 billion years before it expends all of its fuel and swells into a red giant star. Eventually, the Sun will convert into a planetary nebula and finally a white dwarf star.

8. Portions of the Sun's atmosphere and outer layers are actually much hotter than its surface, but not as hot as the core of the Sun. Scientists haven't been able to successfully explain these variations in temperature.

9. Our Sun actually has its own name, or names! One of the most common names, used in many languages and derived from Latin, is Sol. This is the origin of terms like "solar" and "Solar System".

10. You can get sunburns or suntans when exposed to the Sun's rays. However, the rays that have this effect on skin are not the visible rays; it's the ultraviolet rays that do this work. That's why you can still get sunburn on a cloudy day, as the clouds only block the sun's visible light.

BONUS FACT:

Earth's yellow sun is the primary source of power of the legendary super-hero Superman. As you may know, the comic books tell us that Superman was born on the planet Krypton, a large world that orbited a red giant sun before it was destroyed. Superman's body is able to efficiently process and use solar radiation to give him strength, speed, invulnerability, X-Ray and heat vision, and power senses. Without the yellow sun, though, he'd just be a big guy who's stronger than average, but would lack any of these other amazing powers.

Sources:

Wikipediawww.nineplanets.org

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