Essay : 01
About 4,700 million years ago, the Solar System was just a spinning disc of dust and gas. The dust began to collect together and our Sun formed at the centre.
Around Sun, lumps of rock joined up to form smaller bodies and, like the Sun, they heated up. But because they were smaller they soon cooled down and became planets. Sun accounts for 99.85 per cent of mass of the solar system.
The immense gravitational pull of Sun keeps the planets rotating around it in definite orbits. Sun together with the planets were formed essentially at the same time and from the same primordial material. This is evident from the orderly revolution of all nine planets along Sun’s equatorial plane. The most acceptable theory of planetary evolution is the nebular hypothesis.
The Solar System includes a multitude of objects ranging in size from tiny sand like grains to gigantic balls of rock, tens of thousands of miles in diameter.
In the Sun’s family there are: (i) nine planets; (ii) thirty- one satellite moons; (Hi) thousands of planetoids; (iv) millions of meteors; and (v) numerous comets.
These bodies travel around the Sun at high speeds. They travel around the Sun in paths called orbits, at distances ranging from millions to billions of miles.
The Solar System is tucked away in a corner of the Milky Way at a distance of about 30,000 to 33,000 light years from the centre of the galaxy.
The Solar System originated in a primitive solar nebula-a rotating disc of gas and dust. It is from this rotating disc that the planets and the rest of the solar system evolved. The solar system has a diameter of about 11,790 million km.
Essay : 02
The solar system consists of nine planets, of which the earth is the one and the star in the centre is called the sun. This solar system is tucked away in a corner of a Milky way at a distance of about 30,000 to 33,000 light years from the centre of this galaxy. This system contains nine planets—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
A planet means a wanderer. Unlike the stars which have a fixed position, the planets shift their positions and velocity and are never stationary The first five planets are named after Roman gods. The inner planets (Mercury Venus, Earth 86 Mars) are highly dense and rocky They resemble like the earth and are aptly called ‘terrestrial planets’.
The solar system is very big and Jupiter is the largest of all planets. Astronomy tells us so much about these celestial bodies. The Earth is the only gifted planet which has life.
Researches are going on experimenting life on Mars. The chances seem bleak. Man continues his quest to know more about the planets. With every technological innovation and scientific invention man is taking a step forward towards quenching his thirst for knowing the unknown.