Wednesday, April 10

Universe Solar System

Introduction to Universe Solar System:

Family of the sun is given the name solar system. Sun is the centre of solar system. Nine planets are revolving around the sun in the elliptical orbits. The distnace of the planets from the sun and their velocities keep on changing as they revolve around the sun.

Some other heavenly bodies also revolve around the planets and are called satellites. These are also called moons of the planets. Some other heavenly bodies revolving around the sun are asteroids, comets and meteors etc.

Let us discuss about universe solar system and its objects in detail:

Description of universe solar system:

1. Sun:

- It is the nearest star that we can see.

- It shines of its own.

- It is also called luminous body of our solar system

- The mass of the sun is 1.99 x 1030 kgm and its diameter is 1.4 x 109 m.

- It is about 109 times the diameter of the earth.

- The average distance of the sun from earth is about 1.496 x 1011 m, which is called one astronomical unit (A.U.). It is a unit used for the measurement of large distances.

- Sun rotates about its axis from east to west and completes one rotation in approximately 30 days.

2. Planets:

- Planets appear to be bright and do not emit light of their own. They reflect light of sun.

- These heavenly bodies revolve around the sun in elliptical orbits.

- Nine planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. These planets are written in the order of increasing distance from the sun.

Some other Objects in Universe Solar System:

3. Asteroids:

- Asteroids are very tiny planets (pieces of large planets) revolving around the sun between the orbits of Mars and Jupiter.

- Like regular planets, asteroids also revolve in elliptical orbits nearly in the same plane as that of the earth.

- The largest asteroid is called Ceres having radius  350 km and the smallest one is having radius only 50 m.

4. Comets:

- Comets are made up of rock like material surrounded by large masses of easily vapourised substances like water, ammonia and methane.

- The comets revolve around the sun in elliptical orbits.

- As comets come closer to the sun, the water vaporizes due to heat of sun.

- The light of sun exerts a pressure on these vapours and forces them to move away from the comet in the form of a tail.

- Edmund Halley discovered a comet in 18th century named as Halley's comet. This comet completes its orbit around the sun in 76 years. It can be seen in the sky after every 76 years. Last, Halley's comet was seen from earth in April 1986.

5. Meteors:

- When comets break while approaching the sun, the smaller pieces become visible.

- When they enter earth's atmosphere and heat up due to friction, they catch fire while moving towards earth.

- Therefore, we see a streakof light during night.

- These 'shooting stars' are known as meteors.

- They are of different sizes and weights.

- Most of them are in small sizes, and get completely burnt and do not reach earth. These are called meteors.

- Some heavy meteors landing on the earth are called meteorites.

- One of the biggest meteorites fell in Siberia on June 30, 1908.

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