Learning the order of the planets in the solar system should be a relatively easy thing to do; after all there are currently only eight planets to remember. It is though very easy to forget one or to get them in the wrong order, and so over the years people have developed mnemonics to remember the planetary order.
Until a few years ago one of the most common mnemonics was My Very Energetic Mother Just Served Us Nine Pizzas. This mnemonic helped people to remember that the order of the planets, going away from the sun, is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
Mercury – At 46 million miles from the sun, Mercury is the closest of all of the planets. Mercury has almost no atmosphere resulting in a temperature range from 466C to -184C. Mercury is the smallest true planet in the solar system, and is similar in appearance to the Earth’s moon, with a cratered surface. The orbit of Mercury around the sun takes just 88 days.
Venus – Venus is the third brightest object in the sky (after the sun and the moon), and its visibility only at certain periods of the day have given it the name of morning star and evening star. With a similar bulk, size and gravity to the earth it is often regarded as a sister planet to our own. A sulphuric atmosphere ensures though that the surface of the planet is shrouded in mystery. The orbital period for Venus is 225 days.
Earth – Earth is the only planet not to be named after a Roman god, and is the only known planet currently known to support life. The orbit of the earth lasts for 365 days.
Mars – Traditionally known as the red planet, Mars is not as red as it is normally perceived. The fourth terrestrial planet, the atmosphere of Mars is predominantly made of carbon dioxide. One orbit of Mars around the sun takes 687 days.
Jupiter – Jupiter is the first of the gas giants, and comprises a mixture of liquid and gaseous materials, with an atmosphere primarily made of hydrogen. The largest planet to be found in the solar system, Jupiter’s radius is 11 times greater than the earth’s. One orbit of Jupiter around the sun takes 4333 days.
Saturn – The sixth planet of the solar system, Saturn is the second largest planet, and is also one of the gas giants. In terms of composition it is similar to Jupiter, with a similar atmosphere. Saturn though is primarily famous for the thousand rings that circle it. The orbit of Saturn takes 10759 days.
Uranus – The next planet out from the sun is Uranus, the third gas giant, and subsequently the third largest planet in the solar system. The composition of Uranus includes a greater amount of methane, a trait which hives it a distinct blue colouring. One orbit of Uranus takes 30799 days.
Neptune – Neptune is similar in appearance to the other gas giant, Uranus, and like Uranus has an atmosphere of hydrogen and helium, methane, ammonia and water. Like Uranus, Neptune also has a blue colouring.
Pluto – Pluto was for a long time, ever since 1930 considered to be the furthest out of the planets in the solar system. Primarily comprising of rock and ice, it has a totally different composition to the four planets before it. One orbit of Pluto around the sun would take 89866 days.
Even with such a helpful mnemonic as My Very Energetic Mother Just Served Us Nine Pizzas it is still possible to confuse the order of Mercury and Mars, after all both do start with the letter M. This is my most planetary mnemonics start with “My” indicating Mercury, a word like my, that starts with M and ends with Y.
Since 2006 though Pluto is no longer recognised as a true planet and instead was reclassified as a dwarf planet; meaning that the solar system now only consisted of eight planets. A new mnemonic was required, and following on from the food theme, My Very Eager Mother Just Served Us Nachos seems to fit well.
Those people who wish to name Pluto in the planetary list will probably have to also count the other dwarf planets, Ceres, Haumea, Makemake and Eris, giving the possibility of a new mnemonic, My Very Excellent Mother Constantly Just Serves Us Nine Pizzas, Hamburgers, Meatballs, and Eggplants.
