Interesting facts about the Sun
May 28, 2009 | In: Space Facts
The Sun is the nearest star to Earth and is the center of our solar system. Sun is also an operative star that manifests sunspots, solar flares, erupting prominences, and coronal mass ejections.
The Sun is some 30,000 light years from the center of the Milky Way galaxy. At this distance, it takes about 250 million years to complete an orbit around the galaxy.
The Sun has a diameter of 1.4 million km (870,000 miles), mass of 330,000 x Earth, density of 1.41 (water=1), distance to nearest star of 4.3 light years.
The Sun is so big that it could hold 109 planet Earths across its surface.
About 75% of the Sun is hydrogen, the rest is mostly helium.
Solar energy can be collected and stored in batteries, absorbed and transmitted.
The Sun is around 4.5 billion years old.
The sun isn’t on fire in the same way that a piece of paper is on fire. When a piece of paper is set on fire with a match, the atoms (mostly carbon, hydrogen, and oxygen) in the chemical compounds in the paper combine with the molecules of oxygen in the atmosphere to produce the chemical compounds carbon dioxide and water and to release heat and light. This is a chemical reaction that we call combustion. The sun is carrying out a much different process called nuclear fusion. Each second the sun converts 700,000,000 tons of the element hydrogen into 695,000,000 tons of the element helium. This releases energy in the form of gamma rays. The gamma rays are mostly converted to light eventually. This process does not require oxygen. It does require incredibly high temperatures and pressures. The temperature at the core of the sun is about 15,600,000 degrees on the Kelvin temperature scale. The sun is 4.5 billion years old and has used up about one half of its hydrogen fuel supply.
How the Sun Works
The Sun is like a vast hydrogen bomb, continuously exploding.
At the very center is the hottest part of the Sun, the place where hydrogen is fused into helium. Just as in the hydrogen bomb, this creates energy. This is what powers the Sun.
Next, this heat, in the form of gamma-rays (extremely energetic electromagnetic waves), slowly leaks through the thick layer of the hydrogen gas surrounding the core, passing through layers of boiling gas, until it finally reaches the visible surface: the photosphere.
From a temperature of 15 million degrees Celsius (27 million Fahrenheit), it has fallen to a temperature of only 6,000 degrees Celsius (10,000 Fahrenheit) at the visible surface. The struggle to reach the surface has cooled the sunlight and shifted the energy from gamma-rays down to the longer wavelengths of yellow light.
Even so, this temperature is hot enough to vaporize any substance we have on Earth. It is also too hot for hydrogen atoms to exist. The atoms are shattered into their protons and electrons. And it’s at the surface that we see the solar storms forming, often around sunspots — slightly cooler, darker areas of the Sun.
Then, beyond the visible surface, comes the outer atmosphere of the Sun where electrons and protons stream away from the Sun, forming the solar wind that flows throughout the solar system.