Solar System
LEARNING OBJECTIVES
- Become familiar with solar system
- Become aware about the various planets in our social system along with their characteristics
- Develop understanding about our planet 'The Earth'
- Explore about the position and characteristics of moon
INTRODUCTION
Sun is the base of our solar system, and the planets of the solar system revolve around it continuously in different speeds. All the planets have their respective moons except Mercury and Venus. Solar system consists of not only planets but also millions of asteroids, rocks, and so on. The gravity of Sun is the foremost power in our solar system.
The formation of planets and other things available in our solar system are constructed during the formation of Sun. Initially, there were gases and dust particles that formed the Sun, and later, it spread all over. Then, gradually, it became the cause of the formation of various planets. The age of our solar system is approximately four to six billion years.
Scientists believe that our solar system is formed with gas, dust and such other particles (solar nebula). Because of the collapsing of nebula due to gravity, it started spinning faster and compressed into a disc. Whatsoever was spread around was pulled inside and Sun was formed. Rest of the particles collided together and formed planets, moons, and so on. The wind of Sun pushed the lighter objects away and the heavier ones remained in innermost level, and those were small and hard.
It is important to understand that there are no boundaries in space. In our solar system, the entire planets orbit around the Sun. Neptune is the outermost planet that orbits and revolves around 30 astronomical units from the sun. Astronomical unit is calculated as follows:
One astronomical unit = Distance between Sun and Earth (149 million km) As discussed earlier, we have one star, that is, the sun and eight planets in our solar system. However, interestingly, we can see Mercury, Venus, Mars, Jupiter, and Saturn with naked eyes or without any additional instruments like telescopes, but for Uranus and Neptune, we need telescopes to see them.
All planets of our solar system can be categorised into two types, namely rocky (terrestrial) and gaseous planets. Rocky planets include Mercury, Earth, Venus, and Mars. These all have similar composition such as Earth, whereas gaseous planets include Jupiter, Uranus, Saturn, and Neptune, in which Jupiter and Saturn carries highest amount of hydrogen and helium. There are four planets that have rings around them and these are Jupiter, Uranus, Saturn, and Neptune.
PLANETS
The galaxy that we live in is named as 'Milky Way', and it has many planets of different nature, shape, and size. Currently, there are eight planets in our solar system including Earth. As of now, Earth is the only planet that supports life from microorganisms to human beings. In this chapter, we will explore about these planets.
Mercury
It is the nearest planet to the
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