COMPOSITION Mars comprises primarily iron oxide, giving it a reddish hue, alongside silicate rocks, basaltic rock formations, and regolith (surface layer) rich in iron, aluminum, and magnesium. Its atmosphere consists mainly of carbon dioxide with trace amounts of nitrogen and argon. Water exists as ice in polar caps and subsurface reservoirs. Additionally, evidence suggests the presence of minerals like hematite, clay, sulfate salts, and perchlorates, indicating past aqueous activity, contributing to ongoing exploration for signs of past or present life on the planet.