Earth and Space – JSS1 Basic Science Lesson Note (Third Term)

The solar system is the sun and all the bodies that orbit it.

Behavioural objectives

By the end of the lesson, students should be able to:

1. describe the solar system and name the planets in order from the sun;
2. explain rotation and revolution and state what each one causes;
3. state the main facts about the Earth, the sun and the moon;
4. explain the two types of eclipse;
5. define climate and explain how seasons occur.

What is the solar system?

The solar system is the sun and all the bodies that move around it.

• The sun: the star at the centre that gives light and heat to the other bodies.
• Planets: large bodies that revolve around the sun. There are eight.
• Moons: natural satellites that revolve around planets. The Earth has one.
• Asteroids: small rocky bodies that orbit the sun, mostly between Mars and Jupiter.
• Comets: bodies of ice and dust that orbit the sun and may form a bright tail near it.
• Meteoroids: small pieces of rock or metal moving through space.

What are the planets of the solar system?

There are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Order of the planets from the sun

1. Mercury: nearest to the sun and the smallest planet.
2. Venus: second from the sun.
3. Earth: third from the sun and the planet we live on.
4. Mars: fourth from the sun.
5. Jupiter: the biggest planet.
6. Saturn: a large planet with bright rings around it.
7. Uranus: seventh from the sun.
8. Neptune: the farthest of the eight planets from the sun.

What happened to Pluto?

• Old view: Pluto was once counted as the ninth planet.
• Present view: Pluto is now classed as a dwarf planet.

What are rotation and revolution?

Rotation is the spinning of a planet about its axis, and revolution is the movement of a planet around the sun.

• Rotation: the Earth spins about its axis once in about 24 hours.
• Revolution: the Earth travels once around the sun in about 365 days, or one year.

What are the main facts about the Earth?

The Earth is the third planet from the sun and the only known planet that has living things.

• Water: the Earth has water, which with oxygen helps to support life.
• Light: the Earth makes no light of its own, so it is non-luminous.
• Satellite: the Earth has only one natural satellite, the Moon.
• Rotation: the Earth spins about its axis and so gives day and night.
• Revolution: the Earth moves around the sun in about 365 days.

What are luminous and non-luminous bodies?

A luminous body gives out its own light, while a non-luminous body does not.

What are the main facts about the sun?

The sun is a star at the centre of the solar system.

• Light and heat: the sun supplies light and heat to all the planets.
• Luminous: the sun gives out its own light.
• Rotation: the sun rotates about its axis.
• Water: there is no water on the sun.
• Safety: never look straight at the sun, because it can damage the eyes.

What are the main facts about the moon?

The moon is the Earth’s only natural satellite.

• Movement: the moon rotates about its axis and revolves around the Earth.
• Moonlight: the moon reflects light from the sun, which gives the Earth moonlight.
• Non-luminous: the moon makes no light of its own.
• Life: there is no life on the moon.

What is an eclipse?

An eclipse is the total or partial blocking of light from one celestial body by another.

There are two types of eclipse: the eclipse of the sun and the eclipse of the moon.

What is an eclipse of the sun?

An eclipse of the sun happens when the moon passes between the sun and the Earth.

1. The sun, moon and Earth lie exactly in a straight line.
2. The moon is in the middle.
3. The moon blocks sunlight from reaching part of the Earth.
4. People in that part of the Earth see the sun covered, fully or partly.

What is an eclipse of the moon?

An eclipse of the moon happens when the Earth passes between the sun and the moon.

1. The sun, Earth and moon lie exactly in a straight line.
2. The Earth is in the middle.
3. The Earth blocks sunlight from reaching the moon.
4. The moon moves into the shadow of the Earth and looks dark.

Note: at this level, there is no such thing as an eclipse of the Earth.

What is climate?

Climate is the average weather condition of a particular area over a long period.

• Weather: the condition of the air in a place at a given time, such as sunny or rainy.
• Climate: the usual pattern of that weather over many years.

What are seasons and how do they occur?

Seasons are the periods of the year with different weather, caused by the Earth’s revolution around the sun.

1. The Earth revolves around the sun once a year.
2. The Earth’s axis is tilted and keeps pointing the same way as it moves.
3. Different parts of the Earth receive the sun’s rays at different angles at different times of the year.
4. The weather therefore changes through the year.

What changes in day and night length?

• Some months: days are shorter and nights longer.
• Other months: nights are shorter and days longer.
• Some times of the year: days and nights are equal in length.

What are the seasons in Nigeria?

• Rainy season: the months with plenty of rain.
• Dry season: the months with little or no rain.

Evaluation

1. What is a solar system?
2. How many planets do we have? Mention them in order from the sun.
3. What is climate?
4. What is the difference between rotation and revolution?
5. Name one luminous body and one non-luminous body.

Assignment

Answer all parts:

1. Define an eclipse and explain how an eclipse of the sun occurs.
2. Explain how an eclipse of the moon occurs.
3. State two facts about the moon.