Triton
- Neptune's largest moon
- Diameter of 2720 km
- Slightly smaller than the Moon
- Composed of ~75% rock and ~25% water ice
- Retrograde orbit
- Orbits clockwise
- Geologically active
- Volcanism
- Tectonic activity (plate tectonics)
- Largest captured moon
- Larger than Pluto
- Has a high inclination
- Thin atmosphere
- Very high reflectivity
- About 80%
- Reflects most solar energy that falls on it
- Makes it very cold (35-40 K)