Our Earth and Our Solar System – Exercise Solutions

Chapter 1: Our Earth and Our Solar System – Exercise Solutions

1. What’s the solution?

Question: One of the asteroids has fallen out of its place in the asteroid belt and is hurtling towards the sun. Our earth is in its way and there is all likelihood of a collision. What can be done to prevent this collision?

• Answer: We can use rocket technology or space launch technology to send a spacecraft to stop or divert it. This technology provides the tremendous power needed to overcome the earth’s gravity and send objects into space.

2. Use your brain power!

Question (1): What will happen to our solar system if the sun were to suddenly disappear?

• Answer:
  • All the other bodies in the solar system would completely lose their source of light.
  • The planets would stop revolving in their fixed orbits because the sun’s gravitational pull would no longer exist.

Question (2): Suppose you want to give your address to a friend you have on the planet Mars. How will you write your address if you want them to understand exactly where you live?

• Answer:
  • Planet Earth.
  • Between the planets Venus and Mars.
  • The Solar System.

3. Sequence of the Planets

Question: In the picture below, correct the sequence of the planets from the sun.

• Answer: The correct sequence of the planets from the sun is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

4. Who am I?

• (a) You can see me from the earth but the lighted part of me that you see changes every day.
  • Answer: The moon.
• (b) I have my own light. It is only from me that the planets get light and heat.
  • Answer: The sun.
• (c) I turn around myself, around a planet and also around a star.
  • Answer: A satellite.
• (d) I turn around myself and revolve around the sun.
  • Answer: A planet.
• (e) No other planet has a living world like mine.
  • Answer: The earth.
• (f) I am the nearest star to the earth.
  • Answer: The sun.

5. Answer the following questions

Question (a): For what purpose are rockets used in space travel?

• Answer:
  • Rockets are used to send spacecraft into space.
  • They provide the tremendous power needed to overcome the earth’s gravitational force.

Question (b): What information do man-made satellites provide?

• Answer:
  • Man-made satellites provide useful information for agriculture, environment, and weather forecasting.
  • They are used for making maps and searching for water and mineral wealth on the earth.
  • They are also used for telecommunication.