The Solar System is made up of the Sun and all the objects that move around it. It includes eight planets, their moons, asteroids and comets. Basic astronomy facts are regularly asked in geography and general knowledge sections.
The Sun and the Planets
- The Sun is a star at the centre and holds about 99% of the system's mass.
- There are eight planets in order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
- The four inner planets are rocky; the four outer planets are gas and ice giants.
Important Planet Facts
- Mercury - smallest planet and closest to the Sun.
- Venus - hottest planet and brightest in the sky.
- Jupiter - the largest planet.
- Saturn - known for its bright rings.
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Earth and Mars
- Earth is the only planet known to support life, called the Blue Planet.
- Mars is called the Red Planet due to iron oxide.
- Earth has one natural satellite, the Moon.
Other Objects
- Asteroids lie mostly between Mars and Jupiter.
- Comets have bright tails when near the Sun.
- Pluto was reclassified as a dwarf planet in 2006.
Quick Revision Points
- The Solar System has eight planets.
- Mercury is the smallest and closest to the Sun.
- Venus is the hottest and brightest planet.
- Jupiter is the largest planet.
- Mars is the Red Planet; Earth is the Blue Planet.
- Saturn is famous for its rings.
- Pluto became a dwarf planet in 2006.