Color Variations on the Red Planet
Mars looks predominantly red from space due to iron oxides covering its surface, similar to rust.
The color is not uniform, however. Depending on the sun's angle, dust coverage, and mineral composition, light can be scattered differently, causing some areas to appear violet or bluish.
These color variations were captured by the High-Resolution Stereo Camera (HRSC) aboard ESA's Mars Express mission. The images show local deposits where light at certain angles is absorbed more strongly in the blue spectrum.
Scientists interpret the violet tint as indicating different minerals, such as basaltic rocks with low iron content or specific salt deposits that become visible under particular conditions.
Further observations aim to map the distribution of these materials, providing clues about the planet's geological history.