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A Productive History To improve his odds, Anemone turned to Charles “Jay” Emerson, a geography professor who is also based at Western Michigan University. Emerson specializes in interpreting satellite images, including those from the Enhanced Thematic Mapper Plus (ETM+) on the Landsat 7 satellite.

Since 1972, Landsat satellites have observed our planet’s forests, deserts, cities, farms—and badlands. The few paleontologists who have been willing to take advantage of the technology have benefited because, even though Landsat can’t see fossils, it can see the kinds of rocks where they are likely to reside. This is partly because Landsat can see wavelengths of light that human eyes can’t detect. Anything in the universe that is warmer than absolute zero (-273 degrees Celsius) emits electromagnetic radiation. All of that energy—from gamma rays to X rays to radio waves—is referred to as the electromagnetic spectrum. “The retina of the human eye responds to a limited portion of the electromagnetic spectrum,” Emerson explains. The radiation just beyond the human range of vision includes ultraviolet light (shorter wavelengths than blue light) and infrared light (longer than red light).

In addition to blue, green, and red wavelengths, the ETM+ sensor on Landsat 7 can detect infrared radiation, which enables it to distinguish—sometimes better than human eyes—between different rock types. The minerals that make up Earth’s rock layers have distinct chemical compositions and crystalline structures, and tend to reflect different wavelengths in unique ways. The differences occur in visible and infrared wavelengths, or what remote sensing scientists refer to as spectral bands. “Using the seven discrete spectral bands in the Landsat ETM+ sensor,” Emerson says, “image analysts can use different combinations of reflectance to identify different land cover materials.” Anemone and Emerson aren’t the first scientists to turn to remote sensing for fossil hunting. One of their colleagues at the Denver Museum of Nature and Science, Richard Stucky, started working with NASA to explore Landsat’s potential in the mid-1980s. Stucky and colleagues produced a series of “false terrain” images designed to show contrast between different rock types.