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Earth and Space - The Solar System and Planets

Grade 3IB

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

The Solar System consists of the Sun and everything that orbits around it, including 88 major planets, their moons, dwarf planets, and asteroids.

The Sun is a star at the center of the Solar System. It provides energy in the form of light and heat. Its surface temperature is approximately 5,500C5,500^{\circ}C.

The four inner planets (Mercury, Venus, Earth, and Mars) are called terrestrial planets because they are made mostly of rock and metal.

The four outer planets (Jupiter, Saturn, Uranus, and Neptune) are known as Gas Giants or Ice Giants. They are much larger than the terrestrial planets.

Rotation is the spinning of a planet on its axis. For Earth, 11 rotation =24= 24 hours, which creates day and night.

Revolution is the movement of a planet around the Sun. Earth's revolution takes approximately 365.25365.25 days, which we define as 11 year.

The Moon is Earth's only natural satellite. It does not produce its own light but reflects light from the Sun.

📐Formulae

1 Earth Year365.25 days1 \text{ Earth Year} \approx 365.25 \text{ days}

1 Earth Day=24 hours1 \text{ Earth Day} = 24 \text{ hours}

Total Planets=8\text{Total Planets} = 8

Order from Sun: Mercury<Venus<Earth<Mars<Jupiter<Saturn<Uranus<Neptune\text{Order from Sun: Mercury} < \text{Venus} < \text{Earth} < \text{Mars} < \text{Jupiter} < \text{Saturn} < \text{Uranus} < \text{Neptune}

💡Examples

Problem 1:

If Earth takes 2424 hours to complete one full rotation, how many hours does it take to complete 33 rotations?

Solution:

3×24=723 \times 24 = 72 hours

Explanation:

Since one rotation equals one day (2424 hours), we multiply the number of days by the hours in a single day.

Problem 2:

Venus is the hottest planet with an average surface temperature of about 465C465^{\circ}C, while Earth's average is about 15C15^{\circ}C. What is the difference in temperature?

Solution:

465C15C=450C465^{\circ}C - 15^{\circ}C = 450^{\circ}C

Explanation:

To find the difference, we subtract the lower temperature from the higher temperature using the Celsius scale.

Problem 3:

A leap year occurs every 44 years to account for the extra 0.250.25 days in Earth's revolution. Calculate the total extra time added over 44 years.

Solution:

0.25×4=10.25 \times 4 = 1 full day

Explanation:

Because Earth takes 365.25365.25 days to orbit the Sun, adding the 0.250.25 (or 14\frac{1}{4}) of a day over four years equals 11 full day (February 29th).

The Solar System and Planets - Revision Notes & Key Formulas | IB Grade 3 Science