1. Contrast the appearance of colors photographed in natural sunlight with the same colors under incandescent light. What differences do you observe? (In incandescent light, the colors are less vibrant and have a reddish tint.)
2. Contrast the appearance of colors photographed in natural sunlight with the same colors under florescent light. What differences do you observe? (In florescent light, the colors are less vibrant and have a green-blue tint.)
3. How does an electronic flash affect the appearance of a subject’s color? (The flash produces a color balanced light that more closely resembles the color shades you observe in natural sunlight.)
Earthly Cache of Martian Images
Perform a Web search for images of the Martian surface. Do any of the images you uncover offer a 3D view of this alien landscape? If so, how is the 3D effect produced? Do you need any special viewing device to observe the 3D effect? If so, explain how it works. (The red/blue glasses extract independent right and left images and isolate them to each eye. The brain does the rest, constructing a composite image that has three dimensionality based on the differences in the two images.)
Upside Down Confusion
Examine the image on page 67. Describe what you see. Which are the lowest parts of this landscape? Which are the highest elevations? Now, spin the page upside down. Again examine the image. What happened? Why did your perception of what you observed change? Explain how similar ambiguous images might confuse researchers who interpret images transmitted back from robotic explorers.
The red color of the Martian surface is attributed to the rusted iron found in the Martian soil. You can produce your own version of this soil color with some iron filings. Place the filings in a container filled with salt water. After several days, examine the filings. Describe their change in appearance.