Originally posted on Arts & Culture | Smithsonian.
(Photo: Courtesy of Flickr user Phil Shirley)
Attached to an actuator on the shoulder of NASA’s Curiosity Rover exploring Mars right now is a set of panels that looks like an eye shadow compact. It has six pigmented silicone panels—in red, green, blue, 40-percent gray, 60-percent gray, and one with a fluorescent pigment that glows red under ultraviolet light. This is the color calibration target for Curiosity’s Mars Hand Lens Imager, a camera that takes landscape portraits and close-up shots of rocks on Mars (and also selfies). Geologists want some way to know what color these Martian rocks would be on Earth since Earth rocks are all that we’ve been able to study directly with the human eye—and color helps guide theories about a rock’s composition or history.
On Mars, and here on Earth, color matters. Without it, the red Toyota in the parking lot might be indistinguishable from the black one. You want to know if that pear in the market is juicy yellow or hard, inedible green. And let’s not even think for too long about the color of the meat in your fridge, and your assessment of whether it should be dinner, or destined for the trash. Plants and animals use color to protect themselves—a recent New York Times article described how the cuttlefish…