planets

Mercury has an oversized iron core, ice at its poles, and a day longer than its year. What MESSENGER found and what BepiColombo is due to do in November 2026.

Mars looks red because iron in its dust and surface rocks has oxidized into rust-colored minerals. A 2025 study argues the main pigment is ferrihydrite, a water-bearing iron mineral, and that planet-wide winds spread the fine powder that gives Mars its color.

All 8 planets and 5 dwarf planets explained — sizes, atmospheres, moons, missions, and what makes each world unique in our solar system.