18 interesting facts about the Sun

1. Within the core of the Sun, the temperature (15,000,000 K) and pressure (340 billion times Earth's air pressure at sea level) of it is so intense that nuclear reactions actually take place.
2. The Sun revolves around our galaxy (the Milky Way) every 225 – 250 million years (a galactic year).
3. Containing more than 99.8% of the total mass of the Solar System, the Sun is by far the largest object in the Solar System.
4. The Sun orbits the center of the Milky Way galaxy at a distance of approximately 26,000 light-years from the center of the galaxy.
5. 109 Earths would be required to even fit across the Sun's disk, and the Sun's interior could hold over 1.3 million Earths.
6. The Sun is not a solid body, as many people think. It has different regions, which rotate at different speeds. The equator region completes a rotation in about 27 days, but the polar regions take about 30 days.
7. The Sun's energy output, produced by these nuclear fusion reactions, is approximately 3.86e33 ergs/second or 386 billion billion megawatts.
8. The Sun is just another of billions of stars out there. Despite its huge size, it’s tiny: there are many other stars out there that are hundreds of times as large as the Sun.
9. The process that takes this energy to the surface of the sun following complex stages is called convection.
10. As the Sun grows older, it gets brighter and hotter. Over the next few billion years, the Sun will heat up so much that all the heat will burn away life on Earth. But that’s only going to happen after a few billion years.
11. This energy, released as heat as well as light, takes a million years to reach the surface.
12. The Sun is very wide. It has a diameter of about 1.4 million kilometers. To put that in perspective: the Earth has a diameter of about 13 thousand kilometers. It would take more than a 100 Earths to span the entire width of the Sun!
13. The Sun also emits low density streams of particles, also known as the solar wind. These winds blow through the solar system at 450 km/sec and consist mostly of electrons and protons.
14. The Sun is 93 million miles away from the Earth. Light from the Sun takes just over 8 minutes to arrive at Earth. It’s interesting to note, therefore, that if the Sun suddenly stopped shining altogether, it would take us about 8 minutes to realize that.
15. The Sun consists of the core, photosphere, chromosphere and corona, each with differing temperatures and components.
16. Existing for about 4 and a half billion years, it has burnt up about half of the hydrogen in its core. This leaves the Sun's life expectancy to 5 billion more years, at which time, the Sun's elements will "swell" up, swallow Earth, and eventually die off into a small white dwarf.
17. The Sun has structure. It is not simply a huge ball of fire. The surface of the sun is called the photosphere, and is dense with gases. Under the photosphere lies the convective zone, where heat moves to the surface (thus the name : convective), and cooler material falls back down. This layer makes up roughly 70% of the Sun’s radius. Now that’s big. Then comes the radiative zone, where heat is radiated up towards the surface. Then comes the core, where temperatures can easily be around 15,000,000 °C. This is where hydrogen and helium molecules are fused together, to create the light we see.
18. The Sun makes up about 99.8% of the weight of our entire solar system. Its mass is about 2 x 1027 tonnes, and is more than 300,000 times heavier than the Earth.