Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
- Define the term 'habitable zone' and explain how it relates to the ability of planets to support life
- Describe various detection techniques used by scientists to determine the 'habitable zone' of a solar system (i.e., changes in a star's velocity, gravitational pull, magnetism, etc.)
- Recognize the importance of using logic and careful measurements when analyzing data in order to present correct findings and even revisit findings if necessary
- Explain how even scientific "failures" can lead to new discoveries and knowledge
- Use various vocabulary strategies to define academic and domain-specific words in the text
- Cite specific and relevant text evidence to support analysis of the text
- Construct an informative written response that clearly establishes a main point(s), contains relevant textual evidence to support the main point, utilizes transitions to maintain flow, effectively uses domain-specific vocabulary, and provides an appropriate conclusion
Prior Knowledge: What prior knowledge should students have for this lesson?
In regards to science:
- Students should understand the basic definition of a planet and how planets are related to the stars in their solar systems.
- Students should be familiar with the concept of universal gravitation: that based on mass and distance, every object that has mass in the universe attracts every other object that has mass.
- Students should recognize that scientific claims must be evaluated through scientific investigation.
- Students should recognize that alternative scientific explanations must be considered when analyzing data in order to explain the data presented.
- A basic understanding of the Doppler effect would be helpful but not mandatory.
In regards to literacy:
- Students should be able to determine the meaning of unknown and domain-specific words and phrases as they are used in the text.
- Students should have prior experience utilizing various vocabulary strategies, including context clues, to determine the meaning of unknown words in a text.
- Students should be able to respond to a writing prompt in a clear, organized manner that includes use of an introduction to establish the main point(s), a body paragraph that supports the main points and includes relevant textual evidence, and an adequate conclusion.
Guiding Questions: What are the guiding questions for this lesson?
1. Why did researchers first believe that the two exoplanets (Gliese 581d and Gliese 581g) they thought they had discovered were in the habitable zone?
- The amount of shift recorded by researchers while measuring the shift and the pattern of the star's spectrum led the researchers to believe that they had found low mass planets the correct distance from their star. This placed them in a region where liquid water could be present on the surface of the planet, which is part of the definition of a habitable zone.
2. Why did the researchers change their original conclusions based on further investigation?
- As the researchers developed more precise instruments to measure the velocity change as a result of the Doppler shift, their original findings came into question. The changes found by the researchers were similar to changes that can be caused by small planets, but they were also those that can be given off by the star itself. The Doppler shift caused by a small planet could also be caused by changes in the magnetic field of the star, such as sunspots. They were originally looking at the star's absorption lines, which are very sensitive to magnetic activity.
Teaching Phase: How will the teacher present the concept or skill to students?
1. Begin the lesson by asking students: "What would a planet need to be like in order to support life?"
- Answers might include energy, air, water, food, etc.
2. Ask: "Why might scientists be interested in finding planets that could possibly sustain life?"
- Answers might concern the deterioration of planet Earth (water and air pollution, population, climate change, etc.), leading some to believe that alternative habitations should be explored.
- Another answer might include the idea that if liquid water is common in the universe, then it might also lead to the concept that life might also be common.
- There is also the natural curiosity about what else is "out there," and whether or not mankind is alone in the universe.
3. Show , titled "What is the Habitable Zone?" (5:08, uploaded by YouTube user Fraser Cain), about what constitutes a habitable zone.
- Compare the content with what students brought up in their answers.
4. Ask: "How do scientists and astronomers go about finding other planets that may be capable of supporting life?"
- (Introduce the word habitable and its forms: habitat, habitation.)
5. Show the video "How to Find an Exoplanet" (5:30, uploaded by YouTube user minutephysics).
NOTE: If needed, use other videos from the Extensions section to review ways scientists investigate the existence of planets, the Doppler Shift, etc.
6. Tell students they are going to read an informational text about astronomers' research into proving or disproving the existence of planets in the habitable zone. The article provides an example of how scientific findings or claims must be evaluated through logical thinking, and it shows that alternative explanations may be necessary to explain the findings.
- Misconceptions revolve around this difficult subject in that exoplanets are nearly impossible to see. We don't actually visually see them. We see evidence of them by how the star they orbit moves. This is why the search for exoplanets is so difficult. The amount of "wobble" of a star is what is measured, and the smaller the object orbiting the star and the farther away that star system is, the harder it is to detect any change in movement. The level of precision has to be extremely high for anything to be detected.
- The habitable zone is a great starting point, but it isn't everything. Venus and Mars fall within the habitable zone from our sun, but we know that neither planet is habitable. It has to do with the atmospheres creating a "greenhouse" which keeps the temperatures relatively stable as well as prevents harmful radiation from reaching the surface.
- The distance of any exoplanet would be so vast that it would be impossible for us to visit. Many are hundreds of light years away. We don't have any possibility with current technology to go anywhere near them. All we can do is look and hypothesize.
- The point of this lesson should be centered on how these measurements are so difficult to take. What the scientists thought were planets turned out not to be. Pure science can accept mistakes and works to correct them. This must have been very difficult to do, as many top researchers' names were attached to these "discoveries." To have them rescinded must have been very difficult.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
1. Provide each student with a copy of the article.
2. For class discussions that will follow, it might be helpful for students to have a version of the text numbered by paragraph, perhaps after the initial reading.
3. Provide each student with a note-taking guide.
4. Have students fill out the note-taking guide as they read the text. This can be done individually, in pairs, or in small groups. The teacher should monitor students as they work, providing support and guidance as needed.
5. For academic and/or domain specific vocabulary, students should be able to use a variety of vocabulary strategies to define the meaning of the words.
6. This article contains several embedded definitions; the teacher should model using embedded definitions to assist in determining word usage and/or meaning:
- Example: "Some of the signals, initially thought to be coming from two planets orbiting the star at a distance where liquid water could exist, actually were coming from the star itself, not from the "Goldilocks" planets, so-named because conditions on them are 'just right' for supporting life."
- Example: "These "Doppler shifts" can result from subtle changes in the star’s velocity caused by the gravitational pull of orbiting planets."
Formative Assessment (How will teachers check for student understanding?):
1. Teachers can check students' understanding by collecting students' completed note-taking guides, checking their work, providing written feedback, or grading the assignment. Or, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.
2. Teachers can use this sample answer key to the note-taking guide to help them assess students' answers.
3. For discussion on students' answers to the defined vocabulary words, teachers are encouraged to not only ask students to explain the meaning they determined for a word, but the strategy they used to arrive at that meaning. This will allow the teacher to provide alternative suggestions as to how the student could have arrived at the correct meaning of the word.
Misconceptions: See Teaching Phase, above.
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
1. Provide each student with a copy of the text-dependent questions to complete.
2. Students should be reminded to continually refer back to the text and to use relevant and specific evidence from the text to support their answers.
Formative Assessment (How will teachers check for understanding?):
1. Teachers can check students' understanding by collecting students' answers to the text-dependent questions, checking their work, providing written feedback, and maybe grading the assignment. Or, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.
2. Teachers can use this sample answer key to the text-dependent questions to help them assess students' answers.
Misconceptions: Please see the text-dependent questions sample answer key.
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
- Close the lesson with a discussion of the significance of this research. Our understanding of how life began on earth and whether conditions on other planets could support life is enhanced by studying other planets.
- Ask: "What might the implications be if life was disovered on a distant exoplanet?"
- Reinforce that scientists must also be open to see how "failed research" – or findings that may not support their original hypotheses – can actually lead to further and more precise research. The idea that scientists are proven wrong is difficult for people to understand, yet shows the power of science. Always searching for the right answers helps us explain things and moves us forward.
To end the lesson, show students this short video with visuals of more discovered planets: .
- The teacher may wish to review the sample written response as a whole group in order to invite discussion/ideas. Alternatively, after students' written responses have been graded and returned with feedback, teachers might wish to use a sample response from the class.
- Students who are struggling writers can benefit greatly from seeing a well-organized, detailed written response. Going over how the response is structured, pointing out ways to open and close the piece, showing use of effective transitions, and pointing out places to incorporate the natural use of vocabulary can really help students grow in their own writing skills for future writing tasks.
- The teacher could show a sample response on an overhead orwithanLCD projector and discuss some of the following:
- Have students examine how the topic is introduced in the opening sentences of the introductory paragraph. Go over how this writer opened his or her piece of writing. Brainstorm with students other ways the writer could have opened the piece.
- Point out the use of some textual specifics in the body paragraphs that support the author's point by using text evidence.
- Point out how transition words and phrases make the essay more readable and flow better.
- Have students examine how the topic is concluded in the final sentences of the last paragraph. Brainstorm with students other ways the writer could have closed the piece.
Using evidence and citing examples from the text, explain the steps the researchers took to examine their findings in their search for exoplanets, and explain how those findings could be interpreted two different ways. Describe how the "active consideration of alternative scientific explanations" served as an incentive to further investigations.
- Students will individually respond to the writing prompt at the end of the text-dependent questions. They should be directed to respond with a multi-paragraph response, with a clear introduction, body section, and conclusion. They must refer back to the text as they construct their response.
- Provide students with a copy of the rubric and go over it with them so they will know how their written response will be assessed.
- Go over the writing prompt with students and make sure students understand what the prompt is asking them to address. Encourage students to underline key parts of the prompt as the teacher goes over it so they will remember to answer all the required parts.
Teachers will use the rubric to assess students' written responses.
Specific suggestions for conducting Formative Assessment can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "How will you check for student understanding?"
Feedback to Students
Specific suggestions for conducting Feedback to Students can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "How will you check for student understanding?"