Which planet is often called the Red Planet due to its iron oxide surface?

• A. Mars
• B. Mercury
• C. Jupiter
• D. Saturn

Answer: (A)

The color of a planet often comes from what its surface and atmosphere reflect. Mars appears red because its surface is covered with iron oxide—rust-like dust and soil—that gives a distinct reddish hue when sunlight hits it. That iron-rich dust is spread across the planet, making Mars stand out as the Red Planet.

Mercury is a rocky, grayish world with a cratered surface, while Jupiter and Saturn are massive gas giants with colorful cloud bands, not a solid red color from iron oxide. So the planet most clearly associated with a red, iron-oxide surface is Mars.