Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Solar System consists of the Sun, eight planets, their moons, and other celestial bodies. The Sun is at the center and is a huge ball of hot gases, mainly Hydrogen () and Helium ().
The eight planets in order of increasing distance from the Sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
The Earth performs two types of movements: Rotation and Revolution. Rotation is the spinning of Earth on its own axis, which is tilted at an angle of .
Rotation causes Day and Night. The side of the Earth facing the Sun experiences day, while the side facing away experiences night. One full rotation takes hours.
Revolution is the movement of the Earth around the Sun in a fixed elliptical path called an orbit. One complete revolution takes approximately days.
The revolution of the Earth, combined with its tilted axis, causes the change in seasons: Summer, Winter, Spring, and Autumn.
The Moon is the Earth's only natural satellite. It does not have its own light and reflects the light of the Sun. It takes about days to orbit the Earth.
Earth is known as the 'Blue Planet' because approximately of its surface is covered with water ().
📐Formulae
💡Examples
Problem 1:
If the Earth takes days to complete one revolution, explain why we have a Leap Year every years.
Solution:
A Leap Year has days.
Explanation:
Since the Earth takes an extra day each year, after years, these quarters add up to one full day: day. This extra day is added to the month of February every fourth year.
Problem 2:
Why do we see different phases of the Moon during a month?
Solution:
Because of the Moon's revolution around the Earth.
Explanation:
As the Moon orbits the Earth, different portions of its sunlit side are visible to us. The angle between the Sun, Earth, and Moon changes, creating phases from New Moon to Full Moon.
Problem 3:
Calculate the total number of hours in one Earth rotation.
Solution:
Explanation:
The Earth rotates once on its axis every hours, which defines the length of one solar day ().