Mars for Earthlings > Lesson Modules > In-Class Activity 1- Scale & Context

Scale & Context

In-Class Activity 1_Remote Sensing

Julia Kahmann-Robinson PhD and Marjorie Chan PhD, University of Utah Department of Geology & Geophysics


Recognize the purpose and need for understanding the scale and context of various remote sensing imaging techniques.


Print off images (or share in .ppt, see Image File) without their captions. See Figure 1 for an example.


Referring to Figure 1-2 (use color images from available .ppt file of images for this module or print off a set for each student)

  1. Hypothesize what might be pictured in Figure 1 & 2.
  2. Describe the basis for their hypothesis.
  3. List at least (4) ideas for gathering other information that could aid in determining what the image is exactly. Explain their reasoning for their choices.


Time to apply these terms for images of Mars.

  1. Have students measure a comparable scale item(s) in their classroom/home and develop an appropriate scale for measurment, similar to Figures 1 & 2. Then, define terms of scale and context, and apply knowledge to Mars imagery.
  2. Encourage students to interpret Figures 3 & 4. Provide students with the scale and context for the images (given in this version in the image caption).
  3. Ask students to discuss whether or not knowing the scale and context of the images has aided them in interpretation.


  1. Discuss and determine definitions of the terms scale and context with your students.
  2. Referring again to Figures 1 & 2 divulge the answer of what the images are (these answers are given in the image captions; keep in mind that the scales of these are small- cm to mm).
  3. Ask students to provide a scale and context for each image.


  • Time permitting, have students explore mission websites such as THEMIS ( ) or HiRISE ( )
  • Students should choose images that interest them. Have them locate and/or find the scale and context of the image. How does it change their observation or interpretation of the image with this knowledge?


  1. Evaluate student response as they interpret the images. Each student should select an image and submit an explanation of the scale and context for evaluation.
  2. Do students have a clear understanding of scale and context as indicated by their answers in the Elaboration section?