What is the Sun
The sun is the warm heart of our solar system. This star is the source of light and heat of our solar system. This important part of our solar system is the reason why life on earth exists.
Orbit and Rotation
Our solar system exists in a galaxy called the Milky Way, and the sun is in the middle of it. The star orbits around the galaxy and it also pulls in other objects, such as asteroids and planets, along with it. This makes up our solar system. The solar system moves along this orbit at 720,000 kilometres per hour. The gas giant also spins at an angle with a tilt of 7.25 degrees. Since the sun is not a solid body, it spins differently at different locations of the earth, because at the equator, the sun spins once every 25 earth days. However, at the poles, the sun spins around once every 36 days.
Our sun was hypothesized to be created by a phenomenon called the solar nebula. This prediction states that the sun was formed by a giant ball of gas and dust. As the nebula collapsed throughout time, the material was pulled towards the centre of the star and that formed our sun. The prediction is better known as the "Big Bang." Since it pulled in other rock, it also formed our planets, including earth! Therefore, when the sun is formed, it also formed our solar system.
The Future of the Sun
The sun is constantly changing and it will become different. It is not forever as well, so what will happen with our sun in the future?
Life on the Sun
Life can not exist in the sun due to its high heat. Its solar flares also make life on the sun dangerous. However, the sun is a crucial part of life on earth and has provided resources like heat and energy for living organisms.
The Eventual End of the Sun
The sun will one day run out of energy, just like any other star. This event is said to happen in 6.5 billion years. When this process starts, the sun will start to lose hydrogen, resulting in the dimming of the star. It will also start swelling to the point where mercury, venus, and maybe even the earth will be engulfed by the sun. Theorists say that this will cause all life on earth to die. After that, the sun will become a white dwarf star.
Size and Distance
The sun has a radius of about 696 kilometres. Even though this may seem like a big number, the sun is not that big because there many stars that are several times bigger than our sun. But, the sun is far more massive than earth; we need 332,946 earths to match the mass of the sun and 1.3 million earths to fill the volume of the sun. The sun is also 150 million kilometres from earth and it will take about 19 years to fly there at a speed of 885 kilometres per hour (which is the average speed of a passenger plane).
The surface of the sun is called the photosphere. The photosphere is a 500-kilometre thick surface where most of the sun’s radiation escapes from. Again, the sun is not a solid body. As a result, the surface is not exactly like most surfaces on planets, but an outer layer of a gassy star. The temperature of the surface reaches 5500 degrees. The radiation from the surface then reaches the earth about eight minutes after the radiation is initially emitted from the sun.
On top of the surface of the sun, the atmosphere houses the chromosphere and the corona. Originating from the Latin word that means “the sphere of colour,” the chromosphere is the red gassy layer seen in most online pictures of the sun. It is the second of the three layers of the sun and it is about 3000 to 5000 kilometres in depth. The chromosphere hovers around a temperature of 4320 degrees celsius. This layer also gives off the rosy red colour in eclipses as the high levels of hydrogen in the sun. The corona is the outermost layer of the sun as it provides a plasma barrier between the sun and space. It also extends very far out and it can be seen during eclipses as well. It is also warmer than the chromosphere and it is less stable as the temperature can fluctuate from 1 million to 10 million degrees celsius. The atmosphere can also house phenomenons such as solar winds, coronal loops, and occasional solar flares.
Solar winds, which are better known as the Northern and Southern Lights, are the auroras that can be seen around the magnetic poles of the earth. The phenomenon can be seen in places near the poles, such as the Arctic, Antarctic, Alaskan, and Scandinavian regions. They also last about 10-20 minutes and can generate light at 1 and 10 million megawatts. Which is equivalent to the energy produced by 1000 to 10,000 power plants. This reaction occurs from electrons that collide with molecules that in turn generate colourful light. These long waves of light can also as long as 1000 kilometres, which makes them easily seen, especially near areas near the poles.
Another reaction in the sun are Coronal loops are irregular magnetic fields in the photosphere. In this reaction, a constant fusion of hydrogen atoms filters through the sun’s core. Through the process of fusion, the hydrogen becomes helium and the fusion reaction releases a lot of energy. The energy heats the gas and they become plasma. The plasma is ejected outwards, specifically towards the corona. But then the matter will curve back inside. These bright curling loops are what we know are coronal loops. One interesting fact about these loops is that the energy is similar to a gamma-ray burst. Then these loops go back towards their source (the photosphere) and the process happens again.
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