Even on Mars, color matters
One of the most important pieces of equipment on the Curiosity rover is not a spectrometer or a laser but a color calibration chart. Nothing is simple when you’re sending a robot on a 354 million mile journey into space, but NASA and Bill Nye (yes, the “science guy”) came up with an ingenious solution to calibrate the colors of the onboard cameras. In order for NASA scientists to be sure that we are seeing “The Red Planet“ in the correct shade of red, they attached red, green and blue color chips to a sundial on the surface of the rover. These reference colors will guarantee the amazing photos we are seeing of the Martian landscape are accurate.
Here is an animated gif of the sundial on the surface of Mars and a close-up shot of it before it left Earth: