Stars & Galaxies
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Stars are huge balls of hydrogen and helium that are formed in galaxies from great big clouds of gas and dust over billions and billions of years. All Stars are suns, just like our sun. Stars are just like people, they have a lifecycle and eventually will die out. Stars begin as cloud clusters of dust and gas. As more dust and gas stick together gravity pulls them together and hold them like glue. Stars twinkle in the in the night sky because of the Earth's atmosphere. The core of the star is extremely hot and produces energy. Some of this energy is released as visible light which makes the star glow.
Planets in our solar system circle around the sun. There are eight planets in our solar system. Smaller planets with solid ground include Mercury, Venus, Earth and Mars. There are four larger gas giants including Jupiter, Saturn, Uranus and Neptune. We are learning new things about our neighboring planets all the time. We send astronauts to space to take pictures, gather information and find out more about them. Their are eight planets inside of our own solar system and thousands of planets outside of our solar system.
The sun is a star at the center of the solar system. It is nearly a perfect sphere of hot plasma and generates a magnetic field. It is the most important source of energy for life on earth. Over the course of history it has been worshiped and feared. The sun provides a vital ingredient for life on earth: sunlight. Vegetation cannot grow without sunlight. The sun is star and is composed primarily of hydrogen and helium. The Sun contains 99.8% of the total mass of the solar system. The sun is 110 times the diameter of Earth which means that 1 million planet Earth's could fit inside the sun.