The Solar System

Our Solar System is made up of the Sun — a vast star at its centre — and everything that orbits around it: eight planets, dozens of moons, millions of asteroids, and countless comets. The eight planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A helpful sentence to remember the order is: ‘My Very Excellent Mother Just Served Us Nachos.’ The four planets closest to the Sun (Mercury, Venus, Earth, Mars) are rocky and relatively small. The four outer planets (Jupiter, Saturn, Uranus, Neptune) are enormous gas giants. Planets orbit the Sun on slightly elliptical paths, and the further away a planet is, the longer its year. Earth takes 365.25 days to complete one orbit; Neptune takes about 165 Earth years! Our Moon orbits Earth and causes the ocean tides. Earth is uniquely suited to life because of its liquid water, protective atmosphere and position at just the right distance from the Sun — sometimes called the ‘Goldilocks zone’.