Unit 23: Planets

Unit Goal

Can-do: Understand and use everyday English to talk about planets.

In this unit, you will learn planet names, parts of the solar system, and how to compare planets. You will also learn how to write an informative paragraph about planets.

What Is the Solar System?

Exercise Context
A colorful educational illustration of the solar system showing the Sun and the eight planets in space, simple labels for Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, bright stars, friendly classroom learning style, clear and easy for A1-A2 English learners

The solar system is the Sun and all the objects that move around it.

The eight planets are:

  1. Mercury
  2. Venus
  3. Earth
  4. Mars
  5. Jupiter
  6. Saturn
  7. Uranus
  8. Neptune

Inner planets: Mercury, Venus, Earth, and Mars.

Outer planets: Jupiter, Saturn, Uranus, and Neptune.

Vocabulary

Word Simple Meaning
planet(s) A large object that moves around a star.
Earth The planet where we live.
Mercury The closest planet to the Sun.
Venus The second planet from the Sun.
Mars A planet called the Red Planet.
Red Planet A nickname for Mars.
Jupiter The largest planet in the solar system.
Saturn A planet famous for its rings.
Uranus A cold outer planet.
Neptune The farthest major planet from the Sun.
solar system The Sun and everything around it.
moon An object that moves around a planet.
water A clear liquid found on Earth.
land The solid part of a planet.
volcano A mountain that can send out hot rock.
storm Strong wind and bad weather.
comets Objects of ice and dust that travel through space.
dust Very small dry particles.
dwarf planets Small planets that do not meet all planet rules.
🔑 Đáp án & Giải thích

Ghi nhớ:

  • Earth = Trái Đất.
  • Mars = Sao Hỏa (Red Planet).
  • Jupiter = Sao Mộc, lớn nhất.
  • Saturn = Sao Thổ, nổi tiếng với vành đai.
  • Inner planets = các hành tinh gần Mặt Trời.
  • Outer planets = các hành tinh xa Mặt Trời.
  • Solar system = hệ Mặt Trời.

Grammar 1: Comparative and Superlative Adjectives

Comparative (So sánh hơn)

Use comparative adjectives to compare two things.

Pattern: A + be + adjective + er + than + B

Examples:

  • Mars is smaller than Earth.
  • Venus is hotter than Earth.

Superlative (So sánh nhất)

Use superlative adjectives to talk about one thing in a group.

Pattern: the + adjective + est

Examples:

  • Jupiter is the largest planet.
  • Mercury is the closest planet to the Sun.

Common Adjectives

Adjective Comparative Superlative
small smaller smallest
large larger largest
cold colder coldest
hot hotter hottest
🔑 Đáp án & Giải thích

Comparative dùng để so sánh 2 đối tượng: Mars is smaller than Earth.

Superlative dùng để nói cái nhất trong nhóm: Jupiter is the largest planet.

Grammar 2: Commas in a Series

Use commas to separate three or more items in a list.

Example:

  • The inner planets are Mercury, Venus, Earth, and Mars.
  • I learned about comets, planets, moons, and stars.

✓ Mercury, Venus, Earth, and Mars

✗ Mercury Venus Earth and Mars

🔑 Đáp án & Giải thích

Khi liệt kê từ 3 vật trở lên, dùng dấu phẩy giữa các mục trong danh sách.

Grammar 3: Staying on Topic in an Informative Paragraph

An informative paragraph gives facts about one topic.

Stay on topic. Do not add unrelated information.

Good Example

Mars is called the Red Planet. It has land and volcanoes. Scientists study Mars because they want to learn more about it.

Not Good Example

Mars is called the Red Planet. It has volcanoes. My favorite food is pizza.

The last sentence is not about Mars, so it is off topic.

🔑 Đáp án & Giải thích

Khi viết đoạn văn thông tin, tất cả các câu nên nói về cùng một chủ đề.

Không thêm thông tin không liên quan.

Worked Examples

Example 1: Comparative

Question: Which sentence is correct?

A. Mars is smaller than Earth.

B. Mars is smallest than Earth.

Answer: A

Why? We compare two planets, so we use the comparative form "smaller than".

Example 2: Superlative

Question: Complete the sentence.

Jupiter is the ______ planet.

Answer: largest

Why? Jupiter is number one in size among the planets.

Example 3: Staying on Topic

Question: Which sentence does not belong?

1. Neptune is an outer planet.

2. It is very far from the Sun.

3. I like playing soccer after school.

Answer: Sentence 3

Why? It is not about Neptune.

Remember!

  • Learn the names of the planets.
  • Use comparative adjectives for two things.
  • Use superlative adjectives for the biggest, smallest, hottest, etc.
  • Use commas in lists.
  • Keep all sentences on the same topic when writing a paragraph.