## TL;DR

The Solar System formed ~4.6 billion years ago from a molecular cloud. Sun (99.86% of mass) powers the system via nuclear fusion (H → He). Eight planets: Mercury, Venus, Earth, Mars (rocky inner), Jupiter, Saturn, Uranus, Neptune (gas/ice giants). Asteroid belt (Mars-Jupiter), Kuiper belt (beyond Neptune).

## Core Explanation

Inner planets: small, rocky, few/no moons. Jupiter: largest (11x Earth diameter), Great Red Spot (storm >300 years), 95 known moons (Ganymede largest moon in Solar System). Saturn: prominent ring system, Titan (only moon with dense atmosphere). Uranus rotates on its side (98° tilt). Neptune: strongest winds (2,100 km/h). Pluto reclassified as dwarf planet (2006, IAU).

## Further Reading

- [NASA Solar System Exploration](https://science.nasa.gov/solar-system/)