Celestial symphony
The planet Earth on which we live is part of the solar system. The Sun is a star at the centre of the solar system, and planets and other bodies revolve around it. The nine planets, in order from the Sun, are: the inner planets are Mercury, Venus, Earth, Mars and the outer planets Jupiter, Saturn, Uranus, Neptune and Pluto. A good way to remember them is My Very Educated Mother Just Served Us Nine Pizzas.
Most of the planets are named after ancient gods. Mercury gets its name from the Roman messenger to the gods. Venus, the brightest, is named after the Roman goddess of love and beauty. Earth is named after the soil beneath our feet. Mars is the red planet, named after the Roman god of war. Saturn, thought by the Romans to be the slowest, is named after their god of time. Uranus is the Greek god of the sky and the father of Saturn. Neptune, a deep sea-blue colour, is named after the Roman god of the sea.
The scientific definition of a planet came up only recently. The discovery of other solar-system “wanderers” rivalling Pluto in size caused scientists to ask what wasn’t a planet. In 2006, they came up with three conditions for planethood: A planet must orbit the sun, be large enough so that its own gravity moulds it into a spherical shape, and it must have an orbit free of other small objects. Unfortunately Pluto, the “ninth planet” failed to meet the third condition and downgraded to a dwarf planet.
However, in this memory game, Pluto too has been included.