Remote sensing—interpreting the interaction of light with physical materials—is used in a variety of ways, from medical X-rays to the infrared probing of paintings. Scientists have used it in the exploration of the geology, atmosphere, physical properties, and environment of other planets. How does this work—and why is it useful to us?

Geoscientist Patrick Russell explains how light and matter interact to create a whole spectrum of wavelengths, or “colors” that provide different types of information. A variety of instruments on different spacecraft translate what they “see” into knowledge about the geology of the planet. Mars in particular has been found to host more minerals and surface activity than previously thought.

Closer to home, remote sensing is used in predicting and measuring natural events, above and below the earth’s surface.

Russell is a geoscientist in the Center for Earth and Planetary Studies at the Air and Space Museum.