Every elementary school student at some point or another either had a song or mnemonic device to help them remember the “Nine Planets” in order from the sun, outward. MVEMJSUNP (with just the planets), or sometimes SMVEMAJSUNP (showing the positions of the sun and asteroid belt, making the mnemonic itself a little easier to pronounce.) The letters stand for “Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.”
However, since the recent redefinition of “planets” and the addition of a newer term “dwarf planet,” that mnemonic has been cut a little short and the total number of planets reduced to eight. However, we can still use it to help remember the order.
First, we have the sun (named “Sol”) as the center of our solar system, which is located about two-thirds from the center of the barred-spiral shaped Milky Way Galaxy in the minor arm called the “Orion Arm.” After the sun formed and started drawing particles toward it by gravity, they slowly started taking shape into the planets we know today. The four planets closest to the sun are known as the Terrestrial Planets, all of which have a central, solid core and rocky surface made of minerals. The next four planets are known as Gas Giants, each lacking a hard surface and otherwise made of gaseous substances.
MERCURY
In the first orbit around the sun is the planet Mercury (like all planets but Earth, named after an ancient Roman deity.) Mercury has no atmosphere due to its size and close position to the sun; its solar-pointing side reaches extreme high temperatures while its night-time side, due to the lack of significant atmosphere to hold in the heat, reaches extreme low temperatures. Additionally, the northern and southern poles never see sunlight and actually are capped with ice.
VENUS
The next planet is the yellow-colored Venus, named after the goddess of beauty. However, the surface of this planet is far from beautiful. Storm clouds of sulfur and rains of sulfuric acid continuously shower the terrestrial surface. Though farther from the sun than Mercury, Venus is the hottest planet in our solar system due to the thick atmosphere trapping most of the heat it absorbs. It is also closest to Earth’s size of all the planets, but very unlikely to be life-supporting due to the heavy acidity characterizing this planet.
EARTH
Earth is next and is the one most familiar to anyone reading this. Unlike any other planet, Earth has oceans filled with water, huge ice caps at the poles, and running rivers and streams. As far as anyone can tell, Earth is the only that can sustain life as we know it.
MARS
The red planet extends beyond Earth’s orbit. Named after the god of war because of its red and, therefore, menacing color in the night sky, Mars is actually quite calm compared to Venus. The current robotic probes NASA sent to Mars (Spirit & Opportunity) have recently showed us from the surface some of the wind storms and dust devils that do occur on the planet. The iron-rich soil gives the planet its red color. Thus far, Mars is the next closest planet to being able to sustain life, though much colder and currently lacking any visible or attainable water (though there are frozen ice caps and possibly ice deep underground). Evidence of water in Mars’ past has been discovered by the robotic probes in the form of haematite, a form of iron that only forms in the presence of liquid water. In fact, the large valleys juxtaposed with high mountains greatly suggests Mars may have once been a “blue” planet, covered in oceans.
ASTEROID BELT
Separating the terrestrial planets from the gas giants is a wide belt of asteroids, pieces of a potential planet that never came together. Asteroids are called “little planets” because they are huge compared to meteors, many of which are comparable to the sizes of moons around other planets.
JUPITER
The largest in our solar system and named after the king of the Roman gods, Jupiter is a huge, gaseous planet known for its “Big Red Spot” which is a big red storm. Had the conditions been right, Jupiter could have become a star. That is, if the gases that make up the planet had been able to condense to the point of explosion, Jupiter would have been a star instead of a planet. However, it remains one of the most colorful and interesting planets in our solar system.
SATURN
By far the most interesting planet is Saturn, next in our trip outward from the sun. Its rings, visible with even a cheap telescope, are actually bands of circulating ice crystals and minerals. They are supposed to have been a moon that never had a chance to form, or possibly remnants from a moon that was destroyed. Saturn’s many moons hold interest to astronomers, as well. One moon in particular (Titan) has been shown to have an atmosphere and to be very Earth-like.
URANUS
Now we come to the planet with the embarrassing name, unless you say it correctly. Because it is a Roman (and therefore Latin) name, it has pure vowel sounds that make the name as such: “Oo-RAHN-oos”, or, if you prefer, “Oo-RAHN-us”. It is NOT “Your-anus” or “Urine-us” as much as middle schoolers enjoy it. Uranus is interesting because of its almost upside-down tilt. Its axis is tilted such that its northern pole dips below its equator.
NEPTUNE
The blue planet always thought to have been another water planet, Neptune was named after the trident-bearing god of the sea. However, no water (nor land) exists on this planet, which now has the distinct honor of being the last actual planet in our solar system.
PLUTO
About the size of our own moon, with a moon of its own that is almost its same size, Pluto has been the butt of many astronomical (read: “cheesy”) jokes. When it was considered a planet, it still did not fit the mold because of its diminutive size and terrestrial surface, unlike the gas giants before it. It is now called a dwarf planet (or, planetoid, if you desire) and is actually considered part of the Kuiper Belt, an orbiting ring of potential planet particulates that remain from the formation of our solar system; this region is also the home of Halley’s comet. Pluto and its moon Charon actually orbit each other almost equally due to their simlar size. (You might picture two kids facing each other, holding onto a flag pole and swinging around in circles, the flag pole being their “point of orbit.”)
PUT IT ALL TOGETHER
Sun, Mercury, Venus, Earth, Mars, [Asteroid belt], Jupiter, Saturn, Oo-RAHN-oos, Neptune, [Pluto], [Kuiper Belt]. If you please, you may remember it as the mnemonic Sometimes Miss V Eats Mustard and Jelly Sandwiches Until Noon (perhaps kidding).
Actually, any way you can come up with to remember the order is perfectly fine as long as it works for you and gives you the actual order. Hopefully, the above information also will help you know the order as well as some minimal information about each planet.
