7 Unique Facts About the Solar System

Sure, there’s a lot we don’t know about space. However, there is a lot we do know!

Here are 7 unique facts about the solar system you need to know.


Ever since the Renaissance age when philosophers first started to try to expand their knowledge of what was beyond our own planet, man has been mesmerized by space.

No matter how much we learn, there is always another fact or idea lurking right around the corner.

Whether you’re a budding astronomer or just interested in learning a few facts that you can utilize at your next cocktail party, expanding your space knowledge can be a lot of fun.

If you’re ready to learn a few facts about the solar system, keep reading for a few facts you didn’t learn in middle school.

1. Any Celestial Body Can Have Moons

When most of us think of moons, we picture them orbiting large planets like Earth or Jupiter. In fact, as recently as the early 1990’s, the very definition of what makes a planet a planet included the ability to attract a moon into its orbit.

But while all but two of the planets in our solar system, Venus and Mercury, have at least one moon, other celestial bodies can pick up their own orbiting partners as well.

Any celestial body can have a moon. That’s because planets aren’t the only space objects with a gravitational pull, which is what allows planets and other objects to draw in moons.

Of the facts about the solar system on this list, this one may be one of the most recent to be discovered.

It wasn’t until 1993 that the Galileo probe discovered a one-mile wide moon orbiting a 20-mile wide asteroid that researchers realized that moons might not be reserved for only our major planets.

Since that time, more than 200 minor planets have been discovered to have one or more moons.

2. Pluto is Smaller than You Think

In August of 2006, the International Astronomical Union demoted Pluto from a primary planet to a dwarf planet.

While that came as a shock to the general public, if you know any facts about the solar system, you know that as far as major planets go, Pluto was quite different.

It was a fraction of the size of the next smallest planet, Mercury, which measures just under 4,900 kilometers in diameter.

For comparison, Earth has a diameter of 12,756 kilometers.

Not only is Pluto small compared to the other planets, it’s small compared to a few other Earth-based landmarks.

Measuring from North California to Maine, the United States is almost 2,900 miles across. Pluto is just 1,400 miles across.

3. Asteroids are More Spread out Than Sci-Fi Would Have You Believe

If you’ve ever watched a sci-fi movie with a space scene, you’ve likely seen a field of massive asteroids, packed together tightly and hurtling at high-speeds towards whatever spacecraft the film’s heroes are in.

But that image is reserved solely for science fiction. In reality, asteroids are far more spread out.

Scientists who want to capture images of an asteroid have to use carefully charted plans to get close enough.

Running into an asteroid by chance would be highly unlikely outside of a Star Wars film.

4. Mercury Isn’t the Hottest Planet

Knowing how hot the sun is, it wouldn’t be crazy to assume that the closer a planet is to it, the hotter it’ll be.

But while Mercury is the closest planet to the sun, it isn’t the hottest.

That’s because it lacks a thick atmosphere that would trap warmth around the planet, heating it up.

Venus has a thick atmosphere, as well as a composition that is largely made up of carbon dioxide.

This, in conjunction with the thick atmosphere, creates a greenhouse-like condition that heats the planet to around 875 degrees Fahrenheit. By comparison, Mercury is 800 degrees Fahrenheit.

5. Space is Completely Silent

The first four facts about the solar system on this list centered around celestial bodies like planets and asteroids. This next fact involves everything outside of our Earth’s atmosphere.

Because there is no atmosphere in space, there is also no way for sound waves to travel. This means that space is entirely silent.

Wondering how astronauts are able to communicate with the space station back on Earth or from a shuttle to the International Space Station? Radio waves are able to travel without the aid of an atmosphere, making communication possible.

Despite the ability to make contact using radio waves, the silence of space can still be an isolating, scary experience for astronauts.

6. If Two Objects of the Same Metal Touch in Space, They’ll Become One

Here on Earth, when two separate items bump into one another, they are always separated by molecules of oxygen. But with no atmosphere in space, there are no molecules to separate items that collide.

This means that if you touch two metals of the same type, the molecules of those metals will have no way of knowing where one object ends and the next begins.

The result is a phenomenon called cold welding. The metals will bind instantly upon contact.

This requires astronauts and scientists to be careful about the materials used to construct any equipment that goes into space, to avoid accidental welding.

7. Most of Our Solar System’s Mass is Contained in the Sun

Perhaps the best known of the facts about the solar system is that the sun is at the center.

But a less known fact is why the sun has the gravitational strength to pull in our Earth, seven other major planets, and many other celestial bodies.

The reason this is possible is that the sun makes up 99 percent of the all of the mass in our solar system.

When you consider the size of our own Earth, which is 5.972 x 10^24 kilograms and isn’t even the largest planet in the solar system, and think about that being less than 1 percent of the solar system’s

Discover More Facts About the Solar System

Facts about the solar system are as extensive as space itself. It would be impossible for one person to ever learn all of them, but that doesn’t stop space-buffs from trying.

If you want to learn more facts about the solar system, you need to make sure that you’re using a reputable source.

If you’re ready to start learning more about our solar system, the planets, or any other space fact, we can help. Start by checking out our solar system facts to start expanding your space knowledge today!