Minor Members of Solar System and Constellations : NCERT / CBSE Revision Notes
Other Members of Solar System
Apart from the sun and the planets, the solar system also consists of celestial bodies such as meteoroids, asteroids and comets.
Must Read : Celestial Bodies and Solar System
A meteoroid is a small rock or particle of debris in our solar system. When meteoroids enter the Earth's atmosphere they are called meteors. Most meteors burn up in the atmosphere, but if they survive the frictional heating and strike the surface of the Earth they are called meteorites. As a meteor glows brightly when it falls to the ground it is called a shooting star.
Asteroids are made of rubble and are found in the gap between the orbits of Jupiter and Mars. This gap is called the asteroid belt.
A comet is made up of a bright head and a long tail. A comet consists of rock, dust, water, ice and frozen gases. Comets, too, revolve around the sun periodically, but their period of revolution is larger compared to that of planets. One of the most famous comets is the Halley’s comet, named after the discoverer. Its period of revolution is 76 earth years.
Artificial satellites are man-made and are launched from the earth. Artificial satellites are used for transmission of television and radio signals, telecommunication, weather forecasting and remote sensing.
Stars are always fascinating to mankind. They are the most beautiful celestial bodies about which mankind contemplates. In ancient times, the revolution of the earth around the sun and the apparent position of many groups of stars were studied extensively to explore the universe. A group of stars that can be identified with the shape of an identifiable object like an animal or a known object is called a constellation. Major constellations are the Ursa Major, Orion and Cassiopeia.
The Ursa Major is shaped like a ladle and is also referred to as the Big Dipper. It consists of seven stars placed in the form of a dipper. The stars in the constellation form the shape of a bear, and hence it is also referred to as the Great Bear. In India, it is popularly called the Saptarshi.
Another popular constellation is the Orion, which is shaped in the form of a hunter, and hence is also called the Hunter. The three middle stars represent the belt of the hunter. These stars lead to a brighter star in the sky, called the Sirius.
The Cassiopeia is another constellation, which can be located in the northern sky. As the earth rotates on its axis from west to east, the stars appear to move from east to west. But the pole star, which is located along the axis of the earth’s rotation, does not appear to move as it lies along the earth’s axis and is towards the north of the earth. It helps in identifying directions during the night.