By Jessica Pestka
The sun enables life on Earth as we know it to exist. The sun provides warmth and energy to Earth and keeps it from being just another cold, lifeless planet in the universe. Our sun, as important as it is to us, is actually very common in the universe–it is simply Earth’s closest star. In the known universe, the sun is one of about a billion of similar types of stars.
Historically the sun has been of importance to many societies, so important it even has a day named after it: Sunday. Many cultures believed the sun to be a god and worshiped it as such. Cultures such as the Aztecs and Incas built monuments, offered prayers and made sacrifices to the sun.
The sun is made of hot gases, mostly hydrogen with some helium and other trace elements. The sun’s center is as hot as 28 million degrees Fahrenheit and the surface of the sun averages 10,000 degrees Fahrenheit. These incredibly high temperatures are generated by the nuclear reactions that occur constantly within the sun.
The sun is huge in comparison to Earth. In fact, if the sun were the size of a basketball, Earth would be a tiny dot the size of a pin head, in comparison. Not only is the sun larger than Earth, it is also 300,000 times heavier. The sun is so massive, it burns off 4 million tons of gases every second.
Estimated to be about 4.5 billion years old, the sun is currently in the middle of its lifespan. It is expected to last in the present form for at least 5 billion more years. After 5 billion years, the sun will become a significantly hotter, larger star called a red giant. A red giant is a star that has used up its supply of hydrogen and switches to burning helium for fuel.
Although the sun is vital to life on Earth, it can also be dangerous to humans. The sun is so bright that staring directly into it for any length of time could burn your eyes and result in blindness. Additionally, the ultraviolet rays emitted by the sun cause skin damage, or as we more commonly call it, a tan.