The Sun
by Fahad.Ahmad 3t
The Sun's Name Means:
The Romans called the sun Sol, which in English means sun. In ancient Greece, the sun was called Helios.
Our Sun is not unique in the universe. It is a common middle-sized yellow star which scientists have named Sol, after the ancient Roman name. This is why our system of planets is called the Solar System. There are trillions of other stars in the universe just like it. Many of these stars have their own systems of planets, moons, asteroids, and comets.
What is the sun?
- The Sun gives life to the Earth and the Earth would have no life at all without the energy it receives from the Sun.
- The Sun is only one of millions and millions of stars in the Galaxy.
- We see it as a large round red ball only because we are much closer to the Sun than to any of the other stars.
- Other stars may be larger, brighter, smaller or fainter than our Sun but they are so very far away that we only see them as points of light in the night sky.
- The Earth is one of nine planets that orbit round the Sun in what we call the Solar System.
- Solar is the adjective from Sun and comes from the Latin word for Sun – sol, which also gives us the French soleil. (and the word for Sun in several mother European languages).
- The Sun measures 2,715,395 miles (4.730,005 kilometres) right round (circumference).
- The Sun is 92.96 million miles or 149.6 million kilometres from the Earth.
- The Sun is bigger than can really be imagined, over one million times bigger than the Earth.
- This measurement is taken as one Astronomical Unit and is how we measure distances in our Solar System
- Like all stars, the Sun is composed of a great burning ball of gases. It is made of 92.1% hydrogen and 7.8% helium (helium is from the ancient Greek word helios, which means Sun).
sunspot
We don't often think of the Sun as having cooler areas on its surface. The Sun is far too hot for an astronaut to ever visit, but there are areas which are slightly cooler than others. These areas are known as sun spots. Sun spots are still very hot. However, because they are slightly cooler than the rest of the surface of the Sun, they appear slightly darker in color. The gravitational forces in Sun spots are also stronger than the other hotter areas. Of course, you cannot look directly at the Sun to see these spots because you would damage your eyes. Astronomers have to use special telescopes with filters and other instruments to be able to see the cooler spots on the surface of the Sun.
what is a Thermonuclear fusion
Thermonuclear fusion is the process in which a star produce its light, heat, and energy. This happens at the core of the star. The core is superheated to millions of degrees. This heat travels towards the surface and radiates out into the universe. Through this thermonuclear process, stars "burn" a fuel known as hydrogen. The result is that they create another type of fuel known as helium. However, stars do not burn in the same way that a fire does, because stars are not on fire.
Convection
Heat rises, while cooler gas falls. Have you ever noticed that your basement is always much cooler than upstairs. The same laws of physics apply within stars. Because heat rises while cooler gases fall, the gas within a star is constantly rising and falling. This creates massive streams of circular motion within the star. This is called convection.
solar system
Our Sun is not unique in the universe. It is a common middle-sized yellow star which scientists have named Sol, after the ancient Roman name. This is why our system of planets is called the Solar System. There are trillions of other stars in the universe just like it. Many of these stars have their own systems of planets, moons, asteroids, and comets.
helios
The Romans called the sun Sol, which in English means sun. In ancient Greece, the sun was called Helios.
nuclear fusion
At the center, an ever growing body of mass was forming. As the matter fell inward, it generated a tremendous amount of heat and pressure. As it grew, the baby Sun became hotter and hotter. Eventually, when it reached a temperature of around 1 million degrees, its core ignited, causing it to begin nuclear fusion.