When people speak of the order of the planets, they are referring to their relative distances from the Sun. Earth, sitting between Venus and Mars, is the third closest planet to the Sun. Pluto however, previously the furthest known planet in the solar system, was reclassified as a dwarf planet in 2006.
UNESCO recommends a mnemonic, or memory aid, to remember the order of the planets. This is a sentence in which the first letter of each word relates to the name of a planet. The order is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. UNESCO’s recommended sentence is: “Men Very Easily Make Jugs Serve Useful Nightly Purposes.” (See References 2 - no page numbers given in document). A slightly different version of this is “Men Very Easily Make Jugs Serve Useful Necessary Purposes.” Both of these mnemonics help you distinguish between the positions of Mercury and Mars, as the relevant reminder words begin with “Me” and “Ma” respectively.
Another mnemonic, possibly appealing to mothers, is: “My Very Educated Mother Just Served Us Nine Pickles.” (See References 3). One with a mythological flavour is: “Many Vampires Eat Many Jam Sandwiches Until Nanny Protests.” A third alternative cleverly uses the naming of planets as its subject. This is: “My Very Easy Method Just Speeds Up Naming Planets.” Unfortunately, all three of these fail to offer assistance in differentiating between Mars and Mercury. You can make up your own mnemonic if you don’t like any of the others or find them too difficult to remember.
If you find shopping lists easier to remember than seemingly random sentences about jugs, pickles or vampires, you can use a shopping list to help you remember the order of the planets. The list is: “Melon,” Veal,” “Eels,” “Marmalade,” “Jigsaw,” “Sausages,” “Umbrella,” “Nectarines” and “Plums.” You might even find it useful to have a mental image of each item. Substitute the items in the shopping list with other appropriate items, if you wish, before memorising it.
The best way
The best way to remember the order of the planets is to get to know more about the planets. Find many books about the planets in your local library. Consult trusted online resources, such as those on NASA’s website. Watch television programmes like the BBC’s “The Sky at Night.” That way, it’s likely you will get to know the order of the planets without having to resort to additional memory aids.