Sun
From Wikipedia, a free encyclopedia written in simple English for easy reading.
Our Sun is the source of daylight and holds all the planets, including Earth, in paths which travel around it. It appears as the large bright yellow hot circle seen in the sky during the day.
Astronomy considers it one of many stars in our galaxy, the one the Earth orbits. It is the center of our solar system, because it is the only star in it; it's also the main source of energy for life as we know it.
The Sun lies at the middle of our solar system, with the planets moving around it on all sides. Each planet orbits at its own distance from the sun. The orbits of planets are not exact circles but instead are slightly squashed ones which are called ellipses. The planets nearest the Sun get more heat and are hotter. Those further away get less heat and are colder.
The Sun puts out light, heat and tiny particles called the solar wind.
Solar energy and photosynthesis cause the green color of many leaves and plants, and make order from less ordered molecules by creating more complex molecules, such as sugars, proteins and enzymes.
Nuclear fusion and nuclear fission are used as a human energy source. Other than these, all life relies on the large-scale nuclear fusion that takes place in our Sun.
In the center of the Sun, in its core, great heat and pressure combine hydrogen gas into helium gas which produces large amounts of energy. This is called atomic Fusion.
Darker spots are sometimes seen on the face of the sun these are called Sunspots. The number of sunspots on the Sun changes in a cycle of about 11 years. The number affect the weather on Earth, and can also interfere with electronics.
Scientists called Astrophysicists say our Sun to is a yellow dwarf star in the middle of its life. In about another 4-5 billion years, they think it will get bigger to become a red giant, spread out as far as Earth's orbit. Long before that, all life on Earth would end, as the energy from the sun baked the planet dry.
| The Solar System |
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| Star: The Sun |
| Planets: Mercury • Venus • Earth • Mars • Jupiter • Saturn • Uranus • Neptune |
| Dwarf planets: Ceres • Pluto • Eris |
| Small solar system body: Asteroid belt – Comets – Meteors – Kuiper belt – Scattered disc – Oort cloud |
| Other: Moon |
