The origin of the solar system has been debated by scientists, theologians, and other grand high muckity-mucks since time immemorial. While there’s no pinpointing an exact date and time when our solar system arrived on the premises, the good people at NASA have given a ballpark estimate of 4.5 billion years.
According to NASA, a cloud of interstellar gas and dust collapsed after getting caught in the shockwave of an exploding star. The collapsed cloud formed a swirling body of matter whose gravitational pull drew more matter into its center. The pressure there created a massive amount of energy, which eventually formed our sun.
Got all that? If not, don’t worry – we’ve created a rundown of facts about our solar system that you can use to familiarize yourself with it. On the other hand, if you got straight A’s in science class and consider yourself an authority on all things solar, here’s a chance to test your knowledge and see how much you really know.
2 / 36
alex-mit / iStock
1. Earth is not even close to the center of the galaxy
For most of human history, scientists and theologians alike believed in the geocentric theory of the universe, which basically boils down to the belief that Earth is at the center of the universe, and everything revolves around it, including the sun. As it turns out, we’re approximately 165 quadrillion miles away from the center of the Milky Way.
2. The closest planet to the sun has ice
Mercury is the closest planet to the sun, but despite that, it has some ice on the surface. The ice is found in craters that are never exposed to sunlight, but don’t mistake that for a sign that human beings could live there. The average temperature on Mercury is 354 degrees Fahrenheit, it can go as high as 800 degrees and at nighttime can reach -330 degrees, which puts it firmly outside the reach of “bring a sweater” weather.
3. Pluto used to be a planet but it isn’t any more
For a long time, it was an article of faith that our solar system has nine planets. Then, in 2006, the International Astronomical Union decided that one of them, Pluto, did not meet the criteria for being a full-fledged planet, because it had not yet “cleared the neighborhood around its orbit.” It was designated a “dwarf planet” and now the solar system consists of eight planets.
4. Neptune has really, really high-speed wind
Neptune has winds that blow at speeds that easily outpace anything that we have on Earth. According to NASA, some of the winds can blow at speeds of over 1,100 miles per hour, and to put that in perspective, the speed of sound back here on Earth is just 767 miles per hour.
5. There might be a ‘Planet X,’ and it’s really far away
Pluto may have been demoted from a planet to a dwarf planet, but we may still have a ninth planet just the same. Known to the cognoscenti as “Planet X,” it’s believed to orbit the sun even farther out than Pluto does, and may take between 10,000 and 20,000 of our years to go around the sun just once. But remember, this is all still theoretical, according to the Caltech astronomers who did the research, so don’t strap on your astronaut suit just yet.
6. Why is the existence of ‘Planet X’ still just a theory?
According to Jim Green, director of NASA’s Planetary Science Division, the possible existence of a “Planet X” is a prediction based on early modeling. Some of the dwarf planets in the Kuiper Belt follow orbits that cluster together, and the gravity from a potential planet may be what causes them to do this. Or maybe not. It’s still just a theory or, as Green said, “It’s the start of a process that could lead to an exciting result.”
7. If ‘Planet X’ turns out to be real, can they call it the Death Star?
No. The naming rights for a newly discovered planet go to the person who made the discovery. So as tempting as it might be to give it some way cool name out of science fiction, the name will almost certainly end up being the name of a lucky scientist or astronomer whose diligent work has led to the discovery of a new world.
8. ‘Planet X’ could probably be detected with existing technology
The search for Planet X may seem a little fruitless at first. After all, if it’s even further away than Pluto, would modern telescopes even be able to detect it? Perhaps surprisingly, the answer is yes, although it would be so faint that it would be difficult to detect for all but the most experienced astronomers.
9. Your weight on Earth is six times what it would be on the moon
Let’s say you weigh 150 pounds on Earth. Then let’s say you went to the moon. You would find yourself weighing a considerably lighter 25 pounds. At the same time, 17. If you weigh the same 150 pounds on Earth, you would weigh 28 times that on the sun, or 4,200 pounds.
10. The hottest planet isn’t the one closest to the sun
Mercury is the closest planet to the sun, but that doesn’t necessarily mean it’s the hottest. It has no atmosphere, so it can’t retain the heat of the nearby sun. Venus, meanwhile, has an atmosphere that’s 100 times thicker than the one we have on Earth, and it’s composed almost entirely of carbon dioxide, so it reaches an average temperature of 875 degrees Fahrenheit, while the temperature on Mercury tops out at 800 degrees Fahrenheit.
11. This planet has the most volcanoes
Venus isn’t only the hottest planet in the solar system. It’s also the planet that boasts the largest number of volcanoes. The number of volcanoes on Venus exceeds 1,600.
12. This planet also has no moons
Venus may be the hottest planet in the solar system, and it may be the planet with the most volcanoes, but for reasons that scientists have been unable to determine, it has no moons. Not even one! There is, however, research to suggest that it might have had one long ago.
13. Pluto isn’t the only dwarf planet
When Pluto got downgraded from a planet to a dwarf planet, it joined four other bodies that are also classified as dwarf planets. One of them is Eris, one of the largest known dwarf planets in the solar system. It’s also the planet that inadvertently got Pluto demoted to dwarf planet status – at first it appeared larger than Pluto, and it caused the scientific community to reappraise its criteria for planets. When all was said and done, Pluto was a dwarf planet. Stupid Eris!
14. The sun is crazy big
You’ve probably been aware that the sun is very large for a long time and don’t need anyone from the scientific community to tell you that it’s large. But do you know how large? It’s so large that it accounts for 99.86% of the entire solar system, and if that doesn’t put it in perspective for you, think of it this way – all the planets, including Earth and the dwarf planets that we can barely see from Earth live in that remaining 0.14% of the solar system that isn’t the sun.
15. Mars used to have a thicker atmosphere than it does now
While Mercury has no atmosphere to speak of, Mars has a thin atmosphere, although it’s not enough to support the existence of water on the planet. At the same time, people who have studied the planet’s surface have observed patterns that are most likely due to the presence of water at some point. Scientists believe that Mars gradually lost atmosphere to the force of the sun’s energy over the course of millions of years.
16. If you like solar eclipses, it’s a good thing you live on Earth
A solar eclipse is what you get when the sun, moon and Earth are perfectly aligned, causing the moon to cast its shadow on Earth. They don’t happen all that often, but you know where they never happen? Anywhere else, that’s where! If you’re not on Earth, you can’t see a solar eclipse, so solar eclipse fans, stay here on Earth. It will be worth it every few years.
17. Earth is also your go-to destination for water, ice, and vapor
Earth is also the only game in town if you like living on a planet that can have water in three different states – liquid, solid, and vapor. So if you like drinking ice water at the sauna, Earth is the only place where this will be possible.
18. Mars has the tallest known mountain in the solar system
Mount Everest, the tallest mountain on Earth, is approximately 5.5 miles high, and people have perished attempting to conquer it. Meanwhile, the tallest mountain on Mars is more than double that at 14 miles high. Sadly, both men who first climbed Everest successfully, Sir Edmund Hillary and Tenzing Norgay, have long since passed away and cannot lead an expedition to the top of that Martian mountain.
19. Neptune’s winds are the strongest in the solar system
Earlier we said that at over 1,100 miles per hour, Neptune’s winds exceed anything we have on Earth, including the speed of sound. What we didn’t say is how much over 1,100 miles per hour those winds could blow – at their strongest they can reach speeds of 1,304 miles per hour, easily outpacing any other planet in the solar system.
20. You emphasize the first syllable in “Uranus”
This one goes out to all the high school science teachers out there. The seventh planet from the sun has a name that has caused much mirth for schoolchildren and nonstop headaches for the people tasked with teaching them. Well, the party’s over, kids. The planet’s name is pronounced by emphasizing the first syllable – the “YER” – and the letter “A” gets pronounced not as a long vowel sound, but as a schwa. You’re welcome.
21. OK, fine, the long ‘A’ sound works too
Technically, either pronunciation of the word “Uranus” is correct, including the one with the long “A” sound. But boy, your science teacher will thank you for making the job a little easier by pronouncing it the first way. Think of it as a passive form of grade-grubbing.
22. Uranus has the coldest planetary atmosphere in the entire solar system
Venus is the hottest planet in the solar system, and the yin to its hot-weather yang is Uranus, which is the planet with the coldest temperature in the solar system. At its coldest, it can reach temperatures of -371.56 degrees Fahrenheit.
23. Mars has the biggest dust storms in the solar system
If you like dust storms, go to Mars immediately! The planet has the biggest ones in the entire solar system, they can last for months, and can cover the entire planet.
24. As much as half the water on Earth comes from interstellar ice
A recent model of the early solar system’s chemistry revealed something interesting about our own planet. As much as half of the water on Earth originally came from interstellar ice that was in abundant supply as the sun formed.
25. Uranus is the third-largest planet in the solar system
In the battle for largest planet, Uranus takes a not-too-shabby third place with a radius of 15,759 miles. In second place is Saturn, whose 36,184 miles radius makes it 945% the size of Earth, and the winner of the biggest planet trophy is Jupiter, whose 43,441 mile radius makes it 1,120% the size of Earth.
26. Venus is the most similar planet to Earth in the solar system
Let’s say the 1996 movie Independence Day were to come true and belligerent aliens from a faraway galaxy came to destroy the Earth. Where would you go? Well, if size, orbit, and composition are the only issues, your best bet is to move to Venus, which has those attributes in very similar proportion to those found here. Sure, it’s completely inhospitable to human life, but the size is very similar.
27. The planets all follow the same path in the sky
The planets in our solar system all orbit in the same direction and are all on the same plane. The path that the planets follow is called the ecliptic, which supports the theory that the solar system formed from a large cloud of dust and gas that condensed and began to spin.
28. It takes 240 million years for the solar system to orbit the galaxy once
If you want to be there at the exact moment the solar system completes one orbit of the galaxy, we suggest that you make other plans instead. Unless you’re planning some diet and exercise regimen that will keep you alive forever, you’re unlikely to be there at the moment of truth, since the solar system takes a full 240 million years to orbit the galaxy just once. And you thought The Irishman was long!
29. If you like traveling at 1,000 miles per hour, stay on Earth
If you’re ever stuck on a long line at the Department of Motor Vehicles that just doesn’t seem to be moving, take heart! The very planet where you live, Earth, is actually spinning at 1,000 miles per hour and orbits the sun at 67,000 miles per hour. So even if you feel like you’re going nowhere, you’re doing it really fast.
30. If you want to see what the solar system looks like, visit Sweden
Sweden isn’t just the land of meatballs and ABBA. It also has the world’s largest scale model of the solar system. According to Sweden Solar System, the Globe in Stockholm represents the sun and the scale is 1:20 million.
31. Please clear your calendar for the next four decades
The solar system is bigger than anyone can imagine, but how big is that exactly? Just ask the Voyager 1 space probe, which was launched by NASA in 1977 to explore the outermost reaches of the solar system. 35 years later, in 2012, it passed the sun’s gas and magnetic environment, a trip of 11 billion miles.
32. How old are Saturn’s rings? No one really knows
From Earth, the rings of Saturn seem like sleek, unbroken circles. On closer inspection, one can observe that the rings actually consist of rock and ice debris that’s attracted to the planet’s gravitational pull.
33. There’s only one asteroid field in the solar system that we know of
For many of us on Earth, our first exposure to an asteroid field was when Han Solo flew the Millennium Falcon through one in 1980’s The Empire Strikes Back. As it turns out, that depiction was not 100% accurate. Apart from the fact that the only one in the solar system that we know of is between Mars and Jupiter, the individual asteroids themselves have a lot of space between them, making Solo’s daredevil evasion tactics wholly unnecessary.
34. Uranus is stormy and tempestuous
A lot can happen in a few decades, both to individual planets and to those of us back here on Earth who like to observe those planets. When Voyager 2 flew past Uranus it looked like a very calm planet, but due to improvements in technology it’s now possible to see that the planet gets a lot more storm activity than previously thought. More remarkable still is that in 2007, the planet got closer to the sun.
35. You’re inside the sun right now
A lot of people think that the sun is just that fiery orb in the sky, but there’s actually a lot more of it than people realize. In fact, you’re sitting inside the sun right now. The ball of light in the sky that we see every day is 93 million miles away, but its outer atmosphere – known as the heliosphere – stretches far beyond what we can see with our eyes. The solar atmosphere not only encompasses Earth, but also reaches to such distant planets as Jupiter, Saturn, Uranus, and Neptune.
Want more facts?
- 75 weird facts you may not believe are true
- The most famous person born every year of the 20th century
