The Earth in the Solar System Class 6 NCERT

Overview: Our Place in the Universe

The universe is the huge space that contains everything we know: stars, planets, moons, dust, gases and galaxies. A galaxy is a very large group of stars. Our solar system is a tiny part of the Milky Way galaxy. At the centre of our solar system is the Sun, which is a star because it gives out its own heat and light. Eight planets move around the Sun in fixed paths called orbits. Earth is the third planet from the Sun. It is special because it has air, water and a suitable temperature for life. When you study this chapter, imagine zooming out: your home is on Earth, Earth is in the solar system, the solar system is in the Milky Way, and the Milky Way is in the universe.

Key Terms You Must Know

Celestial bodies

Natural objects in the sky, such as the Sun, Moon, stars, planets, asteroids and meteoroids.

Star

A celestial body that has its own heat and light. The Sun is the nearest star to Earth.

Planet

A large celestial body that moves around a star in a fixed path and does not have its own light.

Satellite

A body that moves around a planet. The Moon is the natural satellite of Earth.

Orbit

The fixed path along which a planet moves around the Sun or a satellite moves around a planet.

Asteroids

Small rocky objects mostly found in a belt between the orbits of Mars and Jupiter.

Meteoroids

Small pieces of rock or metal that move around the Sun; some enter Earth’s atmosphere and appear as shooting stars.

How to Remember the Solar System Correctly

1. Step 1: Start from the Sun — The Sun is at the centre of the solar system. Do not place Earth or any planet at the centre. Planets revolve around the Sun because the Sun’s gravity holds them in their orbits.
2. Step 2: Arrange the eight planets — The order from the Sun is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A useful memory line is: My Very Educated Mother Just Served Us Noodles.
3. Step 3: Notice the special positions — Earth is third from the Sun, Mars is fourth, and Jupiter is the largest planet. Mercury is nearest to the Sun, while Neptune is the farthest planet in the present NCERT school-level order.
4. Step 4: Connect distance with temperature — Distance from the Sun affects temperature, but other factors also matter. Earth is neither too hot nor too cold, and this helps water remain in liquid form, making life possible.

Worked Examples: Think Like a Geography Student

• Example 1: Identify the body: It gives its own heat and light and planets revolve around it. Step 1: A body that gives its own heat and light is a star. Step 2: In our solar system, the central star is the Sun. Final answer: The body is the Sun, a star.
• Example 2: Why is the Moon called a satellite of Earth? Step 1: A satellite is a body that moves around a planet. Step 2: The Moon moves around Earth, not directly around the Sun like a planet. Step 3: It is natural, not made by humans. Final answer: The Moon is Earth’s natural satellite.
• Example 3: A student says planets shine like stars, so planets also have their own light. Is this correct? Step 1: Stars produce their own light. Step 2: Planets do not produce light; they reflect the light of the Sun. Step 3: So planets can look bright in the night sky but are not stars. Final answer: The statement is incorrect.

Stars and Planets: Clear Difference

Common Mistakes and Exam Tips

• Do not write that the Moon has its own light. It shines because it reflects sunlight.
• Do not confuse revolution with rotation. Revolution means moving around another body; rotation means spinning on one’s own axis.
• Remember that Earth is the third planet from the Sun, not the centre of the solar system.
• Use the word orbit for the fixed path of a planet or satellite. Avoid saying planets move randomly.
• In short answers, mention both reasons for Earth’s uniqueness: air, water and suitable temperature for life.

Practice Questions with Solutions

• Q: What is the solar system? A: Step 1: The solar system includes the Sun and the celestial bodies connected to it by gravity. Step 2: These bodies include eight planets, their satellites, asteroids, meteoroids and other objects. Step 3: Planets move around the Sun in fixed paths called orbits. Final answer: The solar system is the family of the Sun, eight planets and other celestial bodies that revolve around it.
• Q: Why is Earth called a unique planet? A: Step 1: Earth has air, including oxygen, which living beings need. Step 2: Earth has water in liquid form, which is essential for life. Step 3: Earth has a suitable temperature because it is neither too near nor too far from the Sun. Final answer: Earth is called unique because it supports life with air, water and suitable temperature.
• Q: Differentiate between a star and a planet with one example each. A: Step 1: A star has its own heat and light. Example: the Sun. Step 2: A planet does not have its own light; it reflects sunlight. Example: Earth. Step 3: Stars can be centres of systems, while planets revolve around stars. Final answer: The Sun is a star with its own light, while Earth is a planet that reflects sunlight and revolves around the Sun.
• Q: Put these planets in order from the Sun: Earth, Mercury, Mars, Venus. A: Step 1: Recall the order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Step 2: Select only the planets given in the question. Step 3: Arrange them according to their position from the Sun. Final answer: Mercury, Venus, Earth, Mars.

Frequently Asked Questions