Education Always

Level: JHS, Basic 7  |  Subject: Integrated Science  |  Strand: Systems  |  Topic: The Solar System

Curriculum reference: B7.3.2.1 (NaCCA Integrated Science). All the indicators of this sub-strand are merged into one set of notes.

1. What is the Solar System?

• The solar system is the Sun and everything that moves around it: the planets, their moons, asteroids and comets.
• The Sun is a star. It is the centre of the solar system and gives us light and heat.
• A planet is a large body that moves around the Sun in a fixed path called an orbit.
• A moon (satellite) is a body that moves around a planet. Earth has one moon.

2. The Eight Planets

Order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

A way to remember: My Very Easy Method Just Speeds Up Naming.

Group	Planets	Features
Inner (terrestrial or rocky) planets	Mercury, Venus, Earth, Mars	Small, rocky, closer to the Sun, few or no moons
Outer planets (gas and ice giants)	Jupiter, Saturn, Uranus, Neptune	Very large, made mostly of gas or ice, many moons, far from the Sun

Between Mars and Jupiter is the asteroid belt, a ring of many rocky pieces.

3. The Inner Planets

Planet	Key facts
Mercury	Nearest to the Sun and the smallest planet. Very hot by day and very cold at night. No moon.
Venus	The hottest planet because of its thick clouds that trap heat. Often seen as the bright “evening star”. No moon.
Earth	The only planet known to have life. It has water, air and the right temperature. One moon.
Mars	The “red planet” because of its red, rusty soil. Cold and dry. Two small moons.

4. Why Does Earth Support Life?

• It is at the right distance from the Sun, so it is not too hot and not too cold.
• It has liquid water.
• It has an atmosphere containing oxygen for breathing.
• Its atmosphere protects living things from harmful rays of the Sun.

5. Movements of the Earth

Movement	Meaning	Effect
Rotation	The Earth spins on its axis once in about 24 hours	Day and night
Revolution	The Earth moves around the Sun once in about 365 and a quarter days (one year)	Seasons and the length of a year

In Ghana we have two main seasons, the wet (rainy) season and the dry season. A leap year of 366 days is added every four years to use up the extra quarter days.

6. The Moon

• The Moon is Earth’s natural satellite. It moves around the Earth in about 27 days.
• The Moon does not make its own light. It shines by reflecting sunlight.
• The Moon seems to change shape through the month. These are the phases of the Moon: new moon, crescent, quarter, gibbous and full moon.
• The Moon’s pull causes the tides in the sea.

7. Eclipses

• Solar eclipse: the Moon comes between the Sun and the Earth and blocks the sunlight for a short time. Never look at the Sun directly.
• Lunar eclipse: the Earth comes between the Sun and the Moon, and the Moon goes dark.

8. Space Exploration

People use telescopes, satellites and space probes to study space. Satellites help with weather forecasts, phone calls, television and maps. Ghana launched its first satellite, GhanaSat-1, in 2017.

Remember: The Sun is the centre of the solar system. Rotation gives day and night. Revolution gives the year. The Moon shines by reflected light.

Education Always (education.inspiringalways.com). Original notes written to follow the NaCCA Basic 7 Integrated Science curriculum.