The Solar System


Welcome to class! 

In today’s class, we will be talking about the solar system. Enjoy the class!

The Solar System: The Universe, The Planets, The Earth

Solar system

Solar system

The solar system is the description of the position of the earth and other planets in relation to the sun. The solar system comprises of the sun and the nine planets. All the planets revolve round the sun in “elliptical orbits”.

The universe

It is made up of many heavenly bodies, group of stars form clusters which are known as galaxies or nebulas. Our local groups or galaxy i.e. the earth galaxy is known as ‘The Milky Way’. It contains twenty-seven galaxies.

A satellite is a smaller body which moves round a planet. The moon is the natural satellite of the earth.

Below is a summary of the components of the solar system
Planets Number of satellites Distance from the sun in Km Years  it takes to complete revolution
  • Mercury
None 57,600,000 88 days
  • Venus
None 107,200,000 225 days
  • Earth
One 148,800,000 365  days
  • Mars
Two 227,200,000 687 days
  • Jupiter
Twelve 772,800,000 11.9 years
  • Saturn
Nine 1,417,600,000 29.5 years
  • Uranus
Five 2,854,400,000 84 years
  • Neptune
Two 4,468,800,000 164.8 years
  • Pluto
None 5,850,000,000 247.7 years


  1. What is a solar system?
  2. Define
  • Galaxy
  • Satellite
  • Orbit
Other important specifications of the nine planets
  • Mercury:
  1. This is the smallest planet.
  2. It is the closest planet to the sun.
  3. It is the hottest planet being the closest to the sun.
  4. It contains no living thing because of its high temperature.
  5. It has the shortest orbit round the sun.
  • Venus:
  1. This is the second closest planet to the sun.
  2. It contains no living thing.
  3. It is often referred to as THE EARTH TWIN because of their close proximity in size, mass and density.
  • Earth:
  1. This is the only planet where life exists. This is because earth is the only planet that contains oxygen, and force of gravity.
  2. It has one natural satellite known as Moon.
  • Mars:
  1. This planet is believed to have the possibility of supporting some plant’s life.
  2. It has two satellites.
  • Jupiter:
  1. This is the largest planet in the solar system.
  2. Its surface contains gases such as hydrogen and methane with light and dark bands.
  • Saturn:
  1. This is the second-largest planet after Jupiter.
  2. It has three rings around it.
  • Uranus:
  1. This is the only planet that revolves round the sun in a clockwise direction.
  2. It takes Uranus 84 years to complete its orbit.
  • Neptune:
  1. This planet is very cold because of its distance from the Sun.
  2. It has two satellites
  • Pluto:
  1. This is the farthest planet from the sun.
  2. It is the coldest planet.
  3. It has the longest orbit round the sun


  1. Describe the universe.
  2. Give at least one characteristic of each of the planets.       
General evaluation
  1. What is a solar system?
  2. Name the first four planets and describe their characteristics.
  3. State the characteristics of the last planet.
  4. What is a satellite?
  5. Mention the satellite of the earth.

Reading assignment

Essential Geography, O.A. Iwena, Pages 5-7.


  1. What is a solar system? List the 9 planets in order of their distance from the sun.
  2. State three characteristics of the planet Earth.


In our next class, we will be talking about the Earth as a Planet.  We hope you enjoyed the class.

Should you any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.


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9 thoughts on “The Solar System”

    1. Mercury is the hottest dear, not Venus. Mercury is the closest planet to the sun hence it’s the hottest. Venus is even millions of kilometers away from Mercury not to talk of the sun.

  1. Solomon T.Kollie

    Venus is the hotest planet in the solar system because mercury has no atmospheric condition.

    Check this !

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