Topic outline

  • Detecting Orbital Debris Using Albedo: Index:

    Written by: Frances Dellutri, Jr. High / Intermediate Level SpacEdge Education Team and Lynne Zielinski, Manager of EIS Education                                                                                          Updated July 2022

    Title of Lesson: Orbital Debris and Albedo - Middle School
    Grade (Age) Level: Grades 5-8 (Ages 10-13)


    CCCS:   6.8.3, 6.8.7:
    NGSS:  MS-ESS1-3; MS-ESS3-2,3; MS-ETS1-1,4:  see

    Topic: Art, Astronomy, albedo, orbital debris, debris detection


    This lesson provides an introduction to orbital debris to set the stage. The concept of albedo (the ability of surfaces to reflect sunlight) is then introduced in an overview of the “Albedo Experiment,” where students will be guided through an experiment to determine the light reflecting from ‘orbiting’ objects. Concepts in this activity illustrate how albedo is employed in the study of space, specifically, in the detection of orbital debris.  

    When we look at the moon from Earth or the Earth from space, we are seeing reflected light, albedo. Earth is reflecting the sun's light energy and the moon is reflecting light energy from the sun and second hand sun reflection from Earth. Scientists have learned to use albedo in determining the size and shape of space objects that cannot be captured by a camera. The Air Force Phillips Laboratory in Maui, Hawaii uses albedo as one source to conduct measurements to characterize the orbital debris LEO environment. The U.S. Space Surveillance network primarily tracks deep space objects (those with orbital periods greater than 225 minutes) using optical sensors that detect reflected sunlight.  The observed brightness of a space object depends on many factors besides its size, such as its orientation, its surface composition and the viewing geometry.
    This experiment gives a friendly hands-on demonstration of determining and analyzing albedo and takes into account a space object in a mock revolving orientation.

    1. What is Orbital Debris? 

    2. Overview of Albedo Experiment

    3. Procedure for the Experiment

    4. Teacher Feedback to the Academy

    5. Discussion Forum

  • 1. What is Orbital Debris?

    The image is from the embedded video showing space debris orbiting Earth.

    Earth's orbital environment includes natural debris from the universe but the addition of man-made debris has changed that environment since the 1957 launch of  the 58 cm shiny metal satellite Sputnik I.  The information that follows explains the dangerous nature of the increasing amounts of orbital debris and the importance of tracking the debris to formulate plans for its mitigation. The following portions of this lesson allow students to become scientists in understanding how orbital space debris can be tracked using albedo.

    If you cannot view the video in YouTube, click here, Space Debris 1957-2016.

  • 2. Overview of Albedo Experiment

    The Albedo Experiment will allow students to collect data on albedo (reflected light) in real-time from models of items that might be found orbiting the earth in LEO (Low Earth Orbit) or beyond. The sections of this activity will guide you in learning about LEO debris, preparing equipment, the use of the Kepler Light Grapher, and the possible models that you might use to perform the experiment.  

    Albedo is the amount of light that is reflected from a surface. The image below is from "A Blog About the Universe" and illustrates how light from a light source reflects from a surface. In the Experiment noted below, students will use a Control Target to gather data on albedo and compare it to an Experimental Target as the affect of texture, color, etc. on albedo are considered.

    The image depicts sunlight hitting a surface and being reflected at a 90 degree angle from the surface.  If the surface is light is the albedo bounces back more intensely than if the image is darker in color.

  • 3. Procedure for the Experiment

    The Albedo Experiment can be performed very simply with several sources of error to be expected or can be conducted in a more controlled effort with equipment that will allow students to focus on the data collected.  In either situation, the experiment provides students with a forum to collaborate their critical thinking to minimize any difficulties or unwanted variables that may effect their data.

    You will need the following materials for the more controlled experiment:

    • Computer with camera
    • Access to the Kepler Light Grapher:  
    •   see Light Grapher below
      An Albedo Detector Spinner (instructions and equipment found below in written and video form): The Detector Spinner is an excellent tool, but students may be able to design some other tool to allow their models to revolve in and out of the light source.)
    • A light source - this may be a lamp, light bulb, the flashlight app on a device - it should be quite bright and intense
    • A darkened room, or a darkened area behind the revolving model.
    • A Model Albedo Target  to provide and albedo comparison to an Experimental Target. (This may be a model of an asteroid, a potato, or a multi-faceted home-made item that allows practical surfaces for differing light reflection - instructions for the Model Alabedo Target  is found below)
    • Tape to hold the model in place as it moves
    • Instructions for Using the Light Grapher Program
    • The ability to save your Albedo Graph for printing or for reporting.

    Denise Wright is allowing  EIS to use her tutorial video for use of the Light Grapher.  Denise uses the Kepler Light Grapher to model how scientists search for exoplanets. In her video, Denise uses a set-up for exoplanet modeling that does not require the use of the Spinner.  You may find this approach helpful.  Please view her video to understand how to use the Light Grapher

    • The files attached will guide you in constructing the apparatus needed for the Albedo Experiment (that will avoid sources of error), constructing a Control Target, using the Light Grapher webcam to produce light curves of your targets,  and a Procedure Worksheet to collect and analyze data to direct student data discussion.

    • The following video (1.41 minutes) shows the revolution of the NSS Enterprise spacecraft model as a light curve is being generated through the Kepler: Light Grapher  Detector- see below.

    • This video provides a step-by-step explanation to guide you in constructing a spinner to detect albedo.

    • This file is an .swf  (shockwave flash) and it can be downloaded to your computer to allow your computer camera to act as a light sensor and produce a light sensitivity graph noting the albedo produced from the object in the camera's target.

      You may need to load Shockwave Flash loaded on your computer to download this file.

  • 4. Teacher Feedback to the Academy.

    The Academy is delighted you have chosen to participate in the activities listed under 'Detecting Orbital Debris Using Albedo.'  We would greatly appreciate feedback on your experience in the hopes of making this course as valuable as possible.  Kindly give your thoughts in the short survey and add pictures of your students' products.

    Many Thanks!

    -The SEE Academy

  • 5. Discussion Forum

    You are invited to enter constructive comments, suggestions and experiences that you have encountered using the lessons and activities in the Detecting Orbital Debris Using Albedo.

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