Mercury
Mercury is the smallest and innermost planet in the Solar System. With a surface scarred by craters and extreme temperature changes, it completes an orbit around the Sun every 88 Earth days.
- Distance from Sun: ~58 million km
- Diameter: 4,879 km
- Orbital period: 88 Earth days
- Mean surface temperature: -180°C to 430°C
- Moons: None
- Key feature: Heavily cratered surface, no atmosphere
Quick Facts
Mercury has no moons, no rings, and virtually no atmosphere. Its day (sunrise to sunrise) lasts longer than its year. During the day, surface temperatures soar; at night, they plummet.