Kids as Airborne Mission Scientists

What's hot? What's not?
Related subject area: science

Overall problem: Are there active lava flows on Kilauea volcano?

Relationship of problem in this lesson to overall problem: Airborne remote sensing typically involves sensing reflected or emitted electromagnetic (EM) radiation. In addressing the overall problem, students will need to have a basic understanding of the EM spectrum and various forms of EM radiation, especially infrared and visible. In the "Analyzing data" lesson, students will be analyzing reflected visible and mid-infrared images as well as emitted mid-infrared images of Kilauea volcano in Hawaii.

Estimated time required: Three to Four class periods.

Student outcomes/objectives:

  • The student will define reflection, emission, and absorption.
  • The student will recognize reflection, emission, and absorption as interactions of EM radiation with matter. 
  • The student will determine whether it is better to collect remote sensing data for this mission during daylight or at night.

Prerequisite skills or knowledge:

  • Basic understanding of EM radiation
  • Basic internet skills
  • Basic reading and writing skills

Teacher preparation:

  • Print Student Journal / Activity sheets for these activities.
  • Bookmark appropriate websites for students.
  • Carefully examine internet linked activities to identify and gather necessary materials to complete those lessons.

Student reflection and assessment: Student reflection activities   |  Assessment

Education standards supported by this lesson:   

National Science Education Standards | Project 2061 Benchmarks

National Standards for School Mathematics | National Technology Standards | National Geography Standards

Cross-curricular connections to National Education Standards for this lesson:

math | technology | geography

Teacher Activities

 

Student Activities

FRAME the lesson by reminding students that one of the problems that needs to be addressed in KaAMS is: How can aircraft and remote sensing be used to locate active lava flows on Kilauea? We have developed definitions of remote sensing, models of how it works, and become familiar with EM radiation. Now students will begin to use the fundamentals of remote sensing to solve a practical problem: What time of day should the mission be flown?

Teacher note: The remote sensing terms reflected, emitted, and absorbed are very important. 

  • For a discussion of these topics  see teacher notes.
  • You will need to determine the best time to discuss this terminology with your students, however, it is suggested that you wait until after the students explore these phenomena. See Activity sheet: Defining the terms (WHWN-1).

Introduce the following activity by presenting the "When to fly" question, followed by the related problem: 

  • Imagine you walk into your kitchen during the day (or with the lights on) and you notice that the burner on your electric stove is orange. Is it orange because it is hot or because someone painted it orange?

Important teacher note: To help your understanding of the answer to this problem see the diagrams at the bottom of this page. You may want to share these diagrams with your students after completing the first activity.

   

 

 

 

Student activities:

  • Reflect on and discuss the questions: 
    • Should the remote sensing mission over Kilauea be flown at day or at night? 
    • Why?

     

  • Students should complete Activity sheet: Defining the terms (WHWN-1).
  • Reflect and discuss the electric stove scenario: 
    • Is it orange because it is hot or because someone painted it orange?
    • Brainstorm ideas on how you could determine if it is hot or painted.
 
INFORM students that they should carefully observe the activity and develop detailed notes of their observations and ideas. This activity is to help them understand how remote sensors collect different types of energy - reflected, emitted.

Have the students carefully observe the following sequence of events and record their observations and explanations on Activity sheet: Construction paper and hot plate burner demonstration (WHWN-2), questions 1&2.

  1. Place a piece of orange construction paper cut into the shape of a burner and a hot plate set on high next to each other so the students can view them at the same time.
  2. Prompt students to write down their observations.
  3. Prompt students to attempt to identify the source of the orange light coming from each object to their eyes.
  4. Ask students to devise a way to see whether the orange paper is emitting orange light or reflecting it. (The teacher may need to guide this thinking, see teacher notes)
  5. If possible, test their suggestions. 

Teacher note: It is likely that some of the students will suggest turning out the lights and this is an important analogy to the question that is guiding this lesson: Should the mission be flown during the day or at night? Be sure to test this scenario and prompt students to reflect on what happened and how this may help them to answer the question: Should the mission be flown during the day or at night?   

Debrief by asking students to explain the difference between EM radiation that is reflected and EM radiation that is emitted even though they might look the same. See Activity sheet: Construction paper and hot plate burner demonstration (WHWN-2), question 3.

    

 

 

Student activities:

 

 

 

 

 

 

Student activity:

Sample student responses:
  • Reflected EM radiation comes from some source, like the sun, and "bounces off" of an object. 
  • Emitted energy is that which has its origin actually within the object you are observing, i.e., a fire.
 
EXPLORE content.

Remind the students that the orange light they observed from the burner and orange paper is identical, how it is generated is not.

Prompt students to think about a way to know whether or not the orange light that seems to come from the burner (emitted EM radiation) is not reflected from the room lights (reflected EM radiation)? 

Prompt students to record their ideas on Activity sheet: Construction paper and hot plate burner demonstration (WHWN-2A), question 4.

OR

Ask What if you were not allowed to walk over to the stove and feel if it is hot or not (analogous to using an infrared detector), could you still solve the orange paint vs. left-on burner question?  See Activity sheet: Construction paper and hot plate burner demonstration (WHWN-2A), question 5.

    

 

Student activity:

Sample student responses:

  • Turn out the lights, make the room dark.
  • Feel the burner for heat radiation.

 

Student activity:

Sample student response:

  • Use remote sensing!

 
 

TRY using new knowledge about emitted and reflected radiation.

Ask what is the best time to fly the mission over Kilauea and why?

Teacher note: You may need to have students brainstorm characteristics that active volcanoes and the burner have in common. 

Prompt students to write a letter to the NASA mission planner for the volcano mission in which they outline their recommendation for what time of day to fly the mission. See Activity sheet: Construction paper and hot plate burner demonstration (WHWN-2A), question 6.

Remind students to complete the Activity sheet: Reflection page (WHWN-5) for this lesson in their student journals.

   

Sample student response:

  • The mission should be flow at night so that only energy emitted by the lava flows would be detected. With no available sunlight, there would be no reflected energy. 

Student activities:
 
     
Student reflection activities:

Prompt students to think about the following and record their responses on Activity sheet: Student reflection (WHWN-3).

  • Some materials, like the glass in windows, allow certain wavelengths of EM radiation to pass through them and not others. 
  • What types of EM radiation do you think are transmitted through glass, and what types are not transmitted? What experiences do you have with various types of EM radiation and glass?

  • How could you test your ideas?

Assessment:

  • Students define emitted, reflected, absorbed energy.
  • Students differentiate between examples of emitted and reflected energy.
  • Students determine the best time to fly a mission to gather KaAMS remote sensing data. 

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Ideas for math lesson enhancements:
  • Students use a light sensor and measure the light intensity of a source at equal distances from the source. Using the data they collect they make a graph of light intensity as a function of distance. This is an example of an inverse square relationship. 
  • Students research EM radiation emitted by the sun and calculate the percentage of each type of EM radiation the sun emits.

Related National Education Math Standards:

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Ideas for geography lesson enhancements:

  • Students locate and examine IR remote sensing images of various geographic features of the Hawaiian Islands and classify objects by relative temperature.

Related National Education Geography Standards:

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Ideas for technology lesson enhancements:

  • Students research the role of IR detection in improving home heating energy efficiency.
  • Students research the role of remote sensing in agriculture and the impact of introducing such technology in terms of start-up costs and potential long range financial benefits.

Related National Education Science Technology Standards:

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Activity sheet: Construction paper and hot plate burner demonstration
(WHWN-2A) - answer key

NAME __________________

1.      What did you observe when the paper burner and the hot plate burner were held next to one another?

  • Both objects appear orange; orange light is coming into my eyes.

2.      What is the source of the orange light in each case?

  • The source of the orange light is light from the room light or sunlight entering the room. Wavelengths of light corresponding to orange are reflected from the orange construction paper. Wavelengths corresponding to other colors are absorbed by the orange construction paper.
  • The stove is obviously at a high temperature. The temperature of something is a way of describing how violently its molecules are vibrating - the hotter it is the faster they vibrate. Vibrating molecules give off (emit) energy, and it makes sense that the more violent the vibration the higher the energy that is given off. Many objects give off EM radiation of many different wavelengths corresponding to many different types of EM radiation. The burner gives off both heat in the form of IR EM radiation and light in the form of visible (orange) EM radiation.
  • For two identical objects having different temperatures, the hotter object will emit more energy (higher intensity) at all wavelengths. Also, the hotter the object the more energy that will be emitted at shorter wavelengths. In our burner example, if we set the control to medium heat, the burner is warm, but may not give off visible light, so it appears black.  In this case, the burner is giving off light at the relatively long infrared wavelengths that we cannot see with our eyes. As we turn up the heat slowly, the burner will start to glow dull red, then brighter red and finally orange. The reason for this is that as the temperature of the burner gets higher, our eyes initially detect longer wavelengths of red that the burner is emitting.  Eventually as the temperature of the burner increases we see orange because that is the next visible color with a shorter wavelength than red.

3.      Some of the EM radiation we see (and detect with remote sensing devices) is emitted and some of it is reflected. Sometimes we see (or detect) both emitted and reflected EM radiation. Write your definitions of these terms:

reflected EM radiation: reflected EM radiation comes from some source (like the sun), and "bounces off" of an object. This is the same way you see things during the day with your eyes.

emitted EM radiation: Emitted energy is that which has its origin actually within the object you are observing. A fire, for example, is orange or yellow because it is giving off energy at a high enough level to produce orange or yellow light.


4.      Is there any way to know whether or not the orange light that seems to come from the burner (emitted EM radiation) isn't also, orange light reflected from the room lights (reflected EM radiation)?

Turn out the lights and close the blinds.

5.      What if you were not allowed to walk over to the stove and feel if it is hot or not? (This is like using an infrared detector.) Could you still solve the orange paint vs. left-on burner question?

Yes, by using remote sensing and making sure what you are detecting is emitted EM radiation only.

6.      Should the remote sensing mission over Kilauea be flown during the day or at night? In the space below or on another piece of paper, write a letter to the NASA project director for the volcano mission in which you make a recommendation for what time of day to fly the KaAMS mission. Support your recommendation with the evidence you gathered in the orange paper and burner activity.

It would be best to fly at night. At that time, only energy emitted by the lava flows would be detected. With no available sunlight, there would be no reflected energy and you would not have to worry about it confusing you.

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Activity sheet: Student reflection (WHWN-3) - answer key

 NAME __________________

 
1.      Some materials, like the glass in windows for example, allow certain wavelengths of EM radiation to pass through them and not others. What types of EM radiation do you think are transmitted through glass, and what types are not transmitted?

  • Glass allows radio and microwaves, visible and IR EM radiation, and X- and gamma rays to be transmitted through it but not UV. The atoms in the glass tend to hold on to the energy of UV radiation quite a bit longer (even though it is only about 100 millionths of a second!) than other types of EM radiation and as a result that energy tends to be absorbed by the material.

 2.      How could you test your ideas?

  • Choose a type of EM radiation and find a safe way to place glass between it and some detector. Visible EM radiation is tested simply enough with any window. To test radio waves for instance one could take a transistor radio into a green house and see if he/she can tune in a radio station. Can you get a sunburn riding in a car on a warm day with the windows up? Why do some people keep the windows in their car cracked on a hot day or use shades on their windshields while their car is parked?

3.      Remote sensing devices, such as AVIRIS, have many small detectors on them. Each detector is sensitive to either a single wavelength or a small number of wavelengths. List some objects in and around Kilauea volcano. Identify the type of EM radiation each object is likely to reflect or emit.

  • Lava reflects visible and emits visible and IR. In fact, except for very vigorous eruptions, active lava reflects more visible light than it emits. When we observe the flows at night, we get to see the smaller lava-emitted component that would otherwise not be separable from reflected light during the day.

  • Vegetation reflects visible and IR.

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diagrams, Activity sheet: Burner Diagrams (WHWN-4)

 

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Teacher notes on reflected, emitted, and absorbed energy

In short, reflected energy comes from some source (usually the sun), and bounces off of an object into the remote sensing device. This is the same way you see things during the day with your eyes. Emitted energy is that which has its origin actually within the object you are observing. A fire, for example, is orange or yellow because it is giving off energy at a high enough level to produce orange or yellow light. Of course things can get complicated when something is both reflecting and emitting at the same time. That is why it is much easier to collect information about hot targets at night - you know that all the energy you are collecting must be coming from the target itself.

Another complication is that you can have emitted energy that started out at a different source. For example during the day a parking lot will feel hot to the touch. It is being bombarded with mostly visible and short-wavelength infrared energy from the sun. That energy is interacting with the molecules that make up the parking lot. This causes these molecules to vibrate faster which means their temperature increases and they give off heat. In essence the short-wavelength solar radiation has been converted to long-wavelength thermal radiation. There is a lag between the time that the sun goes down and the parking lot stops radiating thermal energy. Absorbed energy is that which goes into a substance but doesn't come out at all, regardless of whether or not it gets converted to some other wavelength. Reflected energy does not ever "get in" and therefore does not increase the energy of the surface at all. This means that you can't detect reflected energy by touching a surface - you have to "stand back" and measure what bounces off.

Imagine if you had a stove that was both painted orange and left on high. Your eyes would be detecting both the reflected and emitted energy. If you wanted to separate them you would measure the orange intensity with lights on then off. The difference would give you the reflected component. The total minus the reflected component would be the emitted component.

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