Lesson 3 of 5 · Signals are not yet a story
Signals are not yet a story
5 minute lesson · 3 checks along the way
Your goal for this lessonDistinguish an instrument measurement from a geological interpretation.
In this lesson 3 sections · 3 checks
Using archive links & definitions
Follow a linked name to explore its archive card. “Back to your lesson” brings you to the same part of the reading.
Read & understand
Match a sensor to a question
Tianwen-1 carried cameras, radar and other instruments. Different sensors respond to different physical properties. An image describes reflected light and visible form; a radar response requires interpretation of how radio waves interact with material. More instruments can test an explanation, but they do not remove the need for calibration and context.
Check 1 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
A buried reflector is not automatically ice
In a fictional radar exercise, a strong subsurface reflection is proposed as evidence of ice. A boundary between other materials could also change the signal. Compare competing models and seek independent observations before making a composition claim. Naming a plausible explanation is the start of inference, not its completion.
NASA’s global Mars view assembled from Viking Orbiter observations. Processing includes calibrated mosaics, interpolated gaps and a synthesized green channel. This is contextual imagery, not Tianwen-1 data.
Look closely
Why does the processing note matter?
See what to notice
It explains how many observations became a global view and prevents treating every displayed pixel as one direct exposure.
Check 2 of 3
10 pointsUse the reading above. You can try again without losing points.
Read & understand
Use the global picture carefully
The accompanying Mars globe is a NASA Viking composite, not Tianwen data. It provides planetary context while demonstrating that a polished image can combine many observations and processing choices. Check the image’s creator, acquisition method and stated processing before using it as evidence for a particular mission’s results.
Check 3 of 3
10 pointsUse the reading above. You can try again without losing points.
Put it together
Your lesson progress
Each check connects to a part of the story. Complete all 3 to earn your 25-point lesson bonus.
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