Exploratour: NASA's Exploration for Life
Autumn Foliage
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Image courtesy of Corel Photography
Click on image for full size
Image courtesy of Corel Photography
This means one way to detect life's activity on a distant planet is to look for significant levels of oxygen.
Other types of bacterial life break down large molecules for energy and create methane or sulfur as a waste product, so scientists would test the levels of these molecules as well.
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