What You Need


  • A map or visual of the solar system
  • Sticky notes or masking tape
Mercury Photo Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington


To introduce students to the planet Mercury and help them develop an understanding of the planet’s composition, geology, and other important characteristics.


At this level, students need to begin to develop the basic facts and ideas they have about the universe. It is important that they begin learning in more detail about the fascinating and boundless world above their heads—which they may or may not yet fully realize is made up of moons, stars, and the nine planets of our solar system.

Because of the complexity of explaining the workings of the universe, students in earlier grade levels were expected to learn about the universe from only an observational and qualitative standpoint. Among the basic benchmarks they should have learned are: (a) the stars above are countless, vary in brightness, and appear to move across the sky; (b) the sun can be seen during the day, the moon sometimes at night; and (c) the earth is one of several planets that orbit the sun and the moon orbits around the earth. (Benchmarks for Science Literacy, pp. 61–62.) Keep in mind, though, that research indicates that elementary-school students have trouble grasping the concepts that the sun is a star and that the earth orbits the sun. (Benchmarks for Science Literacy, p. 335.) It would be worthwhile, therefore, to take the time during this lesson to find out if your students still have trouble with these concepts.

In this lesson, students will have the chance to view the solar system and identify the sun and planets that compose it, which is consistent with recommendations that students begin to pay attention to sizes, distances, and other basic concepts dealing with the universe. Students then will be well prepared to explore a Web resource on the planet Mercury—developed by the Adler Planetarium—which is the central focus of this lesson.


Before students can begin to learn about the planet Mercury, they need a proper introduction to and orientation on the solar system itself. The warm-up activity for this lesson will help you gauge their current understanding of the solar system, while sparking their interest in the subject matter. Look to reinforce the basic concepts highlighted in this lesson's central benchmark as you go.

Find a map or other visual of the solar system to present to the class as the focus of your discussion. Use sticky notes or masking tape to cover the names of the planets and or sun. Read through the questions and directions below before you begin. As you progress, you will reveal the names of the planets if and when students are able to identify them during the series of discussion questions.

Use the Class Discussion teacher sheet as an answer guide for this and the other discussion activities in this lesson.

Note: Encourage a variety of answers and reactions in an effort to create a broad-ranged and free-flowing discussion of students' ideas and feelings about the universe. Allow other related questions to arise during the discussion. Accept all responses and do not provide explanations. The purpose of this activity is simply to draw out what students know about and how they perceive outer space and the solar system in general.

Now place the map on the board with sticky notes or tape covering the names of the planets and the sun.

Ask students:

  • What do you know about the solar system? What kinds of things can be found there?
  • How many planets make up our solar system?
  • Can you name them? Which one is this? [POINT TO THE MAP; REVEAL NAMES AS YOU GO.]
  • What are their locations in relation to the sun? How does this affect the planets?
  • What else do you know or think is interesting about the solar system?

Continue the open-discussion atmosphere as you lead students into the key part of the lesson—the exploration of the planet Mercury.


Students should use their Mercury student esheet, which will help guide them through the online portion of the lesson.

A Closer Look at Mercury
Now that students are better oriented on the basics of the universe and solar system, begin to ask them the questions from Solar System Exploration's Mercury page, which is the primary resource for this lesson. Students may have to click on some of the tabs at the top of the page to find all of the information.

Note: Students should address and speculate on the Mercury questions before they review the site. Allow them some time to react to and discuss possible answers to these questions. Encourage them to make comparisons to Earth and accept all reasonable answers.

Ask students:

  • What does Mercury look like?
  • Where is Mercury?
  • How big is Mercury?
  • How did the planet Mercury get its name?
  • How long does it take Mercury to orbit the sun?
  • What is the temperature on Mercury?
  • What would you weigh on Mercury—more or less than on Earth?

After that, students should work either on their own or in pairs to review the Solar System Exploration's Mercury page. They should read and surf through the site to find the right answers and other related insights about this mysterious planet. Have them take notes, telling them they will be responsible for the material.

When they are finished, go back and discuss the questions asked at the beginning of this lesson. Encourage students to provide the correct answers to these questions and think about and react to how their original answers compare to the actual answers. Allow them to make comparisons between Mercury and Earth. Use the Class Discussion teacher sheet to guide this final discussion/evaluation.

As per the benchmark for this lesson, students should be able to walk away with a basic and more workable understanding of the solar system, the planet Mercury, and how Earth stands in comparison.


Have students do the activity in the "Understanding What You Learned" section of the Mercury student esheet.

You can also use the Planet Mercury Quiz to review the material students learned, gauge how much they retained, and reinforce key facts and concepts about Mercury, Earth, and the solar system. Quiz answers can be found on the Class Discussion teacher sheet.


This lesson may be followed by two Science NetLinks lessons that directly relate to and extend this subject matter:

Messenger Explores Planet Mercury provides students with information about Messenger, a planned NASA mission to explore Mercury. This site provides information about Mercury as well as insight into some of the questions that scientists hope to explore in the Messenger mission.

The Nine Planets is a popular resource providing information and multimedia activities on the solar system.

Welcome to the Planets is a colorful resource developed by NASA and CIT, providing images and interesting insights about the planets, comets, and asteroids of our solar system.

The Space Place is a fun site with online activities that can be done at home or in class, including Dr. Marc's Amazing Things and Do Spacey Things.

NASA Image of the Day Gallery offers a collection of images from the Hubble Space Telescope and the Apollo missions to the moon.

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Lesson Details

Grades Themes Project 2061 Benchmarks National Science Standards