These DAV Class 5 Science Notes and DAV Class 5 Science Chapter 11 Notes – Our Solar System act as excellent revision resources, particularly in preparation for board exams.
Our Solar System Class 5 DAV Notes
→ Solar System: The sun and its eight planets make the solar system.
→ Luminous Body: Abody which produces its own light is called a luminous body, e.g. sun, star, bulb, candle, etc.
→ Non-luminous body: A body which does not produce its own light is called a non-luminous body, e.g. earth, moon, planets, etc.
→ The Sun:
The Sun is at the centre of the solar system. It is a massive sphere of very hot gases. It produces huge energy and light. It appears small because it is very far from us.
→ Solar Energy: The energy from the sun is called solar energy. Almost all the energy on the earth comes from the solar energy.
A celestial body which is huge and moves around a star is called a planet. A planet in the solar system revolves around the sun. The path of the planet is called orbit. Planets do not have their own light. They appear bright because of sunlight reflected from them.
→ There are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
→ Revolution of Earth: The earth makes one revolution around the sun in about 365 days. Seasons change because of earth’s revolution around the sun.
→ Rotation of Earth: The earth rotates around its axis in 24 hours. Days and night happen because of rotation of earth. The portion of the earth in sunlight has day, while the portion opposite it has night.
→ Unique Properties of Earth: This is the only planet where life is known to exist. Due to the following unique properties of the earth, life has been possible on this planet:
- Presence of atmosphere.
- Presence of liquid water on its surface.
- Right size and right distance from the sun; making it neither too hot nor too cold.
→ Satellites: An object which revolves around a much larger object is called a satellite. We usually refer to satellites of the planets in the solar system.
→ Natural Satellites: Celestial bodies which revolve around a planet are called natural satellites. Moon is the only natural satellite of the earth. Saturn and Jupiter have a large number of satellites.
→ Moon: Moon is our nearest neighbor in space. It is a non-luminous body.
→ The moon revolves around the earth and takes about 28 days to make one revolution. It takes the same number of days to complete one rotation on its axis.
→ Artificial Satellites: Man-made satellites are called artificial satellites. Many artificial satellites are in space and they keep on revolving around the earth.
→ Uses of Artificial Satellites:
- For transmission of radio and TV signals.
- For transmission of telephone signals.
- For weather forecasting and remote sensing.
- For collecting information about other planets.
- Aryabhatta was the first satellite from India. It was launched in 1975.
→ Celestial Body: All natural bodies in the space are called celestial bodies.
→ Planet: A celestial body which revolves around a star.
→ Solar System: The family of the sun and its planets.
→ Satellite: A celestial body which revolves around a planet.
→ Luminous body: A body which produces its own light.
→ Terrestrial Planet: A planet which is mainly made up of rocks and metals.
→ Gaseous Planet: A planet which is mainly made up of gas and ice.
→ Solar Energy: The energy from the sun.