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In 2006, Pluto was demoted to a dwarf planet, not a normal, regular one. So should we now say our mom “…Served Us Nothing” and stop there? Or, perhaps, “Served Us Nachos”? Let’s go with “My Very Educated Mother Just Served Us Nachos.”

Using this mnemonic, we can easily remember the order of the planets as follows:

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

What Happened to Pluto? 

Most people still gripe about Pluto’s demotion, but with a little thought, you’ll probably climb on board. You see, not only is Pluto weirdly tiny—much smaller than even our Moon—but many more Plutos have been found. Other bodies in what we now call the Kuiper Belt are similar to little Pluto, such as Quaoar, Makemake, and Eris, with the latter virtually a Pluto twin. 

If Pluto remained a planet, then all the others would have to be planets too, and our mnemonic would stretch out to include “…Served Us Nachos, Quiche, Meatballs, Eggplant Parmigiano”! 

You can learn more about why Pluto is not a planet.

Why the Order of the Planets is Important

Besides knowing the planets’ order, we must also insert planets into one of two category systems. 

The first classification system labels planets by size and composition:

• The first four planets in order from the Sun—Mercury, Venus, Earth, and Mars—are all small, with rocky surfaces and orbits close to one another. 
• From Jupiter outward, the planets are enormous and gassy, possess no surfaces, and have orbits with vast spaces between them. 

Consequently, we have the terrestrial (Earth-like) planets and the Jovian (Jupiter-like, happy) planets.

Inferior and Superior Planets

The second classification system depends on whether a planet is closer to the Sun than we are or farther out. 

The order of the planets from the Sun matters tremendously. Planets farther out, even though they’re not better than Earth, are called superior planets; planets closer to the Sun are called “inferior planets.”

Superior planets appear the biggest, brightest, and closest when opposite the Sun in our sky. When they’re at “�DZ��Dz����پ��Dz�”, Earth is directly between the Sun and that planet, so faster-moving Earth passes each one like overtaking a slow truck on the highway.

Since each subsequent planet farther from the Sun moves slower and has a longer circuit to complete, its “year” greatly increases as it gets farther away. 

It, therefore, makes sense that Mercury zips fully around the Sun every three months, Venus once every eight months, Earth once a year (which you already knew, right?), Mars in a bit more than two years, Jupiter in 12 years, Saturn in 30, Uranus in 84, and Neptune orbiting once in 165 years.

Related: Planet Neptune At Opposition

Planet Opposition

Imagine a straight line formed by the Sun, Earth, and each planet on the day we pass it. That’s when it’s closest and biggest through telescopes, and then said to be at “�DZ��Dz����پ��Dz�”. 

We list each planet’s opposition date in every . Each year, you’ll best see that planet within a couple of months of that date.

The two “inferior planets,” Mercury and Venus, can never be in opposition because we’re never between them and the Sun. Instead, we always look somewhat toward the Sun to see them. 

• Mercury truly hugs the sun like a moth, so it is often tricky to find. It is always in twilight, facing the sunward direction. 
• Venus, thank goodness, swings out as much as 47 degrees from the Sun, enough so that it can sometimes stand comfortably high over the fading twilight, either after sunset as an Evening Star or before dawn as a Morning star. 

All the other planets will stand in any direction at various times.

Planetary Order and the Zodiac

All the planets orbit the Sun in the same flat pancake-like plane. Our Earth orbits in that plane, and so does our Moon whirling around us. The consequence is that there’s an imaginary band around the sky called the zodiac, and all the planets in our Solar System are found within that ribbon of celestial real estate.

It’s called the zodiac, which sounds a bit like “zoo” because a dozen constellations that form its background are mostly animals like Leo the Lion, Scorpius the Scorpion, and Taurus the Bull. Zodiac constellations also include a few non-animalistic patterns, like a set of scales and mythological twins.

Learn the zodiacal constellations, and anytime a bright star appears in one of them, you can bet it’s a planet. 

Now you know the planets in order, and the importance of opposition, the final planet-stuff you want sitting permanently in your brain-pan is an image of what each one is like “in person”, and how they compare to Earth.

Mercury

Smallest planet. Rocky surface. No air at all.

• Facts: Smallest planet and closest to the Sun; temperature can go as low as –290°F at night;
  second densest planet.
• Distance From Sun: 36 million miles.
• Closest distance to Earth: 48 million miles.
• Rotation: 88 Earth days.
• Opposition: No.

Venus

Hottest world, wood-stove temps. Earth-sized. Overcast with thick, high-pressure CO2.

• Facts: One day on Venus is longer than 1 year; 36,000-foot-tall mountain (taller than Mount Everest); thousands of volcanoes.
• Distance from Sun: 67 million miles.
• Closest distance to Earth: 38 million miles.
• Rotation: 225 Earth days.
• Opposition: No.

Earth

Only planet to sustain life.

• Facts: 70 percent ocean; surface includes volcanoes, mountains, valleys, rivers, lakes, trees, plants.
• Distance from Sun: 93 million miles.
• Rotation: 365.25 days.

Mars

Half Earth size. Rocky surface often -10° F. Air is CO2, thinner than ours atop Mt. Everest.

• Facts: Reddish surface due to oxidation; large canyon system (Valles Marineris) Olympus Mons is largest volcano is solar system; water–ice under surface of polar regions.
• Distance from Sun: 142 million miles.
• Closest distance to Earth: 34.6 million miles.
• Rotation: 687 Earth days.
• Opposition: Every 26 months—January 15, 2025.

Jupiter

Biggest planet by far. No surface at all, just thick stormy hydrogen/helium then slush below.

• Facts: Largest planet in solar system; four rings; largest ocean in solar system—made of hydrogen; winds reach up to 335 miles per hour at equator.
• Distance from Sun: 484 million miles.
• Closest distance to Earth: 367 million miles.
• Rotation: 4,333 Earth days (about 12 Earth years).
• Opposition: Every 13 months—December 7, 2024.

Saturn

Huge, with gorgeous rings. Dozens of moons. No surface. Hydrogen and helium again.

• Facts: Seven rings; average density less than water; winds in upper atmosphere reach 1,600 feet per second—more than four times faster than the strongest hurricane-force winds on Earth.
• Distance from Sun: 886 million miles.
• Closest distance to Earth: 746 million miles.
• Rotation: 10,756 Earth days (about 29.4 Earth years).
• Opposition: Every 378 days—September 8, 2024.

Uranus

Four times Earth’s width. Greenish. Spins sideways. Hydrogen compounds, no surface.

• Facts: Two sets of rings (13 total); blue-green color comes from methane gas in atmosphere; near core, temperature can reach 9,000°F.
• Distance from Sun: 1.8 billion miles..
• Closest distance to Earth: 1.6 billion miles.
• Rotation: 30,687 Earth days (about 84 Earth years).
• Opposition: Every 369 days—November 16, 2024.

Neptune

Uranus twin. Cold hydrogen compounds like ammonia and methane. No surface.

• Facts: Triton is the only large moon in the solar system that circles in the opposite direction of its planet’s rotation; 9 rings; windiest planet in solar system with speeds up to 1,200 miles per hour at surface.
• Distance from Sun: 2.8 billion miles.
• Closest distance to Earth: 2.7 billion miles.
• Rotation: 60,190 Earth days (about 165 Earth years).
• Opposition: Every 367 days—September 20, 2024. 

When you read the closest distance to Earth for some of the planets above, it can be hard to apprehend. To grasp the size of our flat solar system, picture riding our fastest rockets, about ten miles a second, at a steady speed. You would need:

• three months to reach Mercury, 
• one month to Venus or Mars,  
• 15 months to Jupiter, 
• 2 ½ years to Saturn, 
• five years to Uranus, 
• 10 years to Neptune, and 
• 15 years to Pluto. 

As for leaving all the planets to reach the nearest star? Bring lots to read. It would take 8,000 years!