The Sun is an ordinary star that is the primary source of heat and light for all the planets in our solar system. This heat and light is the cause of the continuous existence of life on Earth. Without these two crucial elements, we would have never existed when the planet was created.
1) The Distance of the Sun and Earth
How close is the Sun to the Earth?
There is a difference in the distance between the Earth and the Sun in its orbit throughout the year. The Sun is closest to the Earth in the beginning of January with a distance of around 91.3 million miles while in July, the Sun is furthest from the Earth with a distance of 94.4 million miles.
You must be wondering why the northern hemisphere is hotter during the summer when the Earth is more distant to the Sun while the winters are colder with the Sun closer to the planet. The reason why is because the Earth’s axis is tilted. Many people believe that the difference in the seasons is caused by how far the sun is from Earth throughout the year. People think that that the Earth is closer to the Sun in summer which results in high temperatures while it is more distant in the winter resulting in colder climates. However, in fact it is the complete opposite.
During the summer, the sun’s rays hits the Earth in a steep angle with the light being unable to spread out, this helps light focus on different parts of the hemisphere. With longer duration of daylight, it is no wonder why the Earth can warm up quickly. In winter, the sun’s rays hits the planet at a shallower angle with more light spread out. The shorter duration of daylight causes the Earth to lose any heat it collects and eventually cools the climate. This is why temperatures during the long hours of the night fall several degrees below freezing.
2) The Age of the Sun
How old is the sun?
At the moment, the Sun is middle-aged with a span of four and a half billion years. We expect that the Sun will live for another 4-5 billion years until it dies away.
The life cycle of the Sun depends on its own mass. Stars like the Sun spend their life eating up the hydrogen that is located in the centre. This process continues for billions of years with very small changes if not any.
How will the Sun Die?
After the sun reaches near 7 billion old, it will have consumed all of its hydrogen fuel in the core, leaving it with no choice but to expand into a red giant and grow closer to Earth. Soon enough it will first envelop Mercury and Venus which are the closest planets to the Sun and will eventually envelop Earth, ending all life.
During the process of growing into a red giant, the Sun will lose most of its mass and lose all of the outer planets out of their orbits, leaving them flying around in space. Earth and the other inner planets won’t have a chance to do so because they will have been destroyed by the sun’s surface while it continues to grow.
After it puffs out the outer atmosphere to such an extent, the Sun will go through a gentle explosion and will end up being at the centre of a planetary nebula.
What is a planetary nebula?
A planetary nebula is created when a giant star explodes because of a shortage of fuel to help it continue burning. The outer layers of gas expand into space forming a shape of a ring or flower. Their lifetime is very short with spans not exceeding thousands of years. It is at this point when the star is near the final stage of life.
3) The Temperature of the Sun
The temperature of the sun and its outer atmosphere is different. At the centre of the Sun, the temperature rises to a staggering 15,000,000 degrees Celsius. Near to the surface of the Sun is the chromosphere where bright clouds of hydrogen rise above areas where sunspots are about to form. This area of the Sun has a temperature of 6,000 Celsius. Now as we head out of the Sun towards the corona, the temperature suddenly boosts to 1,000,000 Celsius. Immense clouds of gas erupt from the upper chromosphere and appear in the corona. The upper part of the corona stretches far out into space. It can only be seen when total solar eclipses occur.
In all, the Sun is the biggest icon in our solar system. It has enough fuel to last another 5 billion years. You don’t need to worry if the Sun will die off anytime soon. Just enjoy the facts that you learn along the way.
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