This satellite photograph of sediment deposits on Mars doubles as a lush abstract composition. The upper third of the image is made up of layers of striated lines in alternating earthy pastel shades. At the “horizon” line, an edge of brilliant orange light divides the composition. Subtle rays emanate upwards from this edge. Below it, a paler yellow defines the ridges of a puckered surface of raised and pitted areas of lavender and black. To the right, an undulating section of darker color appears razor-thin at the top. Alluvial fans are gently sloping wedges of sediments deposited by flowing water. This image is actually a map to a slice of Mars’ geologic history.