From their differences in sizes, to the impact they could have on Earth, join us as we explore the question, “What’s the Difference Between Comets, Asteroids, Meteoroids, Meteors & Meteorites?”
A Whole Lot Of Rocks!
After hearing names like Comets, Asteroids, Meteoroids, Meteors & Meteorites, you likely are thinking, “that’s a lot of names for what is essentially space rocks!” And you’re honestly not wrong. It does feel like a lot of names are being thrown around for what is honestly just rocks, but you need to think of this in the grander scope of things. Because just like there isn’t “regular planets” out there, or all stars aren’t just one type, all of these rocks have a purpose in regards to their name. Even if it doesn’t look like it at first, which is fine if you think about it, because most of the time we don’t need to know or care about these things. But when it comes to how we look at our universe, we need to differentiate them.
Let’s start at the beginning of everything, ok? Once upon a time, all of these various space rocks didn’t exist. Whether you believe in a God or the Big Bang, the universe didn’t have anything at first, and then, the “wave of creation” was born. For this video, we’ll look at things from the Big Bang perspective. After the wave of energy and mass was delivered throughout the universe. Then, the gravities of various things like stars started to pull things together into tighter and tighter masses. This was how the planets got formed. But for the things that didn’t become planets, they became things like Comets, Asteroids, Meteoroids, Meteors & Meteorites. Which means that these things, or at least many of these things, have been around since the beginning of the universe, and they’ve played a part in shaping a great many things in order to turn the universe, and even our solar system, into what it is right now.
Which means that while these names may feel superfluous, that doesn’t mean they aren’t impactful. And in fact, each and every one of these rocks have an impact whether you admit it or not. So, let’s dive into them, and see what makes them so different, and so special.
So how about we start with obviously the most important one of the bunch, asteroids!
When you think about “world breakers”, you’re likely thinking about an asteroid, and for good reason. Although if we’re being technical, not all asteroids are as big as you think. In fact, they can be quite small. The smallest asteroid that we consider to be an asteroid is about 3 feet in length. Which may not sound that impressive compared to the ones that we’re talking about, but you need to remember, three feet in length is over half the size of an average human. Which means if it were to hit Earth in that form? It could cause serious damage depending on where it lands.
So if that’s the smallest pure asteroid, what would be the biggest? Well that’s a bit tricky, because at one point in time it was a massive rock known as Ceres. This asteroid (at the time) was documented as being 590 miles in diameter, which is about 1/4 the size of our moon. If that thing hit us? Yeah, we’d be in big trouble. But that’s the rub, it’s not a threat, not just because of distance, but because it’s on an orbit that technically won’t have it reach us in any conceivable fashion barring a massive jarring of itself.
Oh, and that’s the second rub, Ceres is so big that they actually made it a planet! Well, it’s actually a “dwarf planet”, but yeah, they think it’s so big that it can’t be called an asteroid anymore. Which is fine I suppose, but it makes you wonder just how many other space rocks need a “reclassification”.
Getting back on track, the scale for an asteroid is now set between 3 feet and 590 miles in diameter. That’s quite a reach, and that’s partially why asteroids are so dangerous. They range in sizes in terms of lengths, and they also have a variety of sizes that make them hard to find, hard to track, and really unpredictable. Some of them are known to be dark masses of clay, yet others are bright shiny rocks made of metals like Nickel, or Iron.
Yet here’s the thing, if we take all the known asteroids in the solar system and beyond? Their combined mass is not even as much as our own moon. To be clear, that doesn’t make them dangerous, but that helps us gauge what to expect from them. Including knowing that a massive planet-sized asteroid ISN’T heading our way anytime soon.
You might be wondering now, “How is it the Earth is so safe from asteroids when there are so many out there?” You can thank our neighborly planets for that. You see, when our universe was formed, and by extension our solar system, it’s true that there were a lot of big rocks floating around. But because of Mars and Jupiter, they were all corralled for the most part and trapped between the massive gravities of these two planets. The collisions that they caused actually created more asteroids of various sizes, but again, they’re mostly trapped. Meaning that Earth isn’t in immediate danger of them…or at least…not yet.
Ok, so enough about asteroids, let’s move onto something smaller, Meteoroids! I bet you didn’t even think Meteoroids were a real thing before this video, right? But you likely know them by their other name, “Shooting Stars”. Confused? I’ll explain. Meteoroids are created in a very natural way, mainly when massive asteroids collide with one another small chunks of them break off and get shot into space via momentum and gravitational forces.
But, unlike Asteroids, these Meteoroids are incredibly small, they’ll never be bigger than 3 feet (the smallest size of a pure asteroid) and they can be as small as a grain of dust. So in theory, there are more Meteoroids out in space than all the other space rocks combined! In theory, it’s really hard to tell given how small they can be.
Anyway, the reason that they are also known as shooting stars is that they can get burnt up in the atmosphere in such a way that they become a “fiery flash” of light. A light so strong it’s said to be even brighter than the planet Venus! They streak across the sky with these intense streaks and then they burn away into nothingness. Thus, they’re shooting stars.
Now, you might be thinking, “Doesn’t that mean that meteors are also shooting stars?” That would be correct, because if Meteoroids enter the Earth’s atmosphere, their classification is turned into Meteors, and Meteors are known to be bigger than Meteoroids, but still do the same thing. They’ll flash through the atmosphere with brilliant intensity and cause the same shooting star effect. And of course, if these things are in enough numbers, they’ll create what is known as a meteor shower. Which is one of the coolest things that you can see in the night sky.
But what you might not realize is that although we may not “see” it, almost 48 tons of Meteoroids and Meteors fall to Earth every day. The reason we don’t notice it though is because of how small they can be, and the angles in which they fall to the Earth. The distinction between them is small, but they do make a difference in the larger scale of things.
“But wait a minute!” you say, “If that’s what Meteoroids and Meteors are, then what are Meteorites?” A very good question, and thankfully, there’s a very simple answer for that. While Meteors and Meteoroids do most times burn up in the atmosphere, not all of them do. Sometimes they’re able to withstand the height of the atmosphere burning them up and they crash land on Earth. When that happens, they become Meteorites.
Meteorites are the things that people at NASA and other space agencies try and find all over the world. There have even been shows on places like Science Channel that highlight the search for Meteorites. Why the need to find them? Because regardless of their size or even where they came from, Meteorites are a window into the creation of the universe itself. Knowing the Meteorites composition, its materials, its makeup, etc, it can help paint a path into where it came from, the events that caused it to fall to Earth, etc.
Meteorites are valuable, extremely valuable in fact. They can sell for thousands of dollars on the internet, and are so desirable that people even try and sell fake ones! Oh yeah, it happens.
The reason for the value is that they’re so rare. Remember, at their core Meteorites are just rocks! And when a rock hits a hard place like the Earth? It means that they shatter, and sometimes even explode! It’s not a pretty thing, and yet, they can be valuable…if they’re in tact enough. I know I said that size doesn’t matter, but if you have an inch of a Meteorite, it’s not that useful. But if you get one that’s about 6 inches? Or a foot? Or even one a few inches across that is shaped like a sphere (which has happened before), that can change things.
It’s really hard to find them, mainly because they’re so difficult to predict in terms of when they’re crash to the Earth, or even where they’re crash into the Earth. And even if they do land and don’t shatter too much, the weather can wither them down like regular stones. Ironically, one of the best places to find intact Meteorites is Antarctica because of how the snow and ice keeps them solid and not withered away. Some of the biggest finds of Meteorites happened in Antarctica, and many more finds are still to come.
Finally, there are Comets! Which are honestly much different from all the other space rocks mentioned.
This is because if we’re being technical, Comets aren’t rocks at all, they’re ice, water, and dust, and they look MUCH cooler than all the other space rocks. You see, Asteroids, Meteoroids, Meteors & Meteorites are all solid rock, inside and out. Sometimes they have metal as well, but the point here is that they’re solid. For a comet though, it’s a nucleus of ice and gasses that have been formed together and they remain in a state of non-solidity that causes them to be much different. Just as important though, while most Asteroids, Meteoroids, Meteors & Meteorites have atypical orbits or are kept in check by planets, Comets have a direct line of orbit with the sun. Which is why they look how they do. Because as they circle the sun, they start to have their ice melted and their gasses expanded, and that creates the unique comet feature called a coma. You know it as its “tail”. This coma can streak across the sky, and can even be thousands of miles long!
That’s important to note because Comets are so bright that they can be seen from Earth at quite a distance, not unlike the stars in the sky. When you see Asteroids, Meteoroids, Meteors & Meteorites, it’s typically because they’re in our atmosphere. But barring something odd happening, you’ll never see a Comet within our atmosphere because of the orbits they have around the sun.
How far are they from Earth? Well because of their composition, they were truly formed in the farthest reaches of our solar system. Most comets are within the Kuiper Belt and the Oort Cloud. Which is beyond Neptune. That’s why the sun doesn’t burn them up, even when they get close to it, it’s just enough heat to make the tail and nothing more.
You know one of the most famous of these Comets I hope? Hailey’s Comet? It’s so big and reliable that it shows up about every 70 years, and it’s been doing that for many generations. We talked about in this post.
Alright, so let’s end this with a bang. Which of these Comets, Asteroids, Meteoroids, Meteors & Meteorites do we need to fear one way or another? Well like we said a little bit ago, barring something weird, you’ll never have to fear a Comet, they’re too out of range. Meteoroids, Meteors & Meteorites CAN be harmful, especially if they hit the atmosphere in just the right way. Obviously it’s the Meteorites that hit the Earth, and there have been some extremely unfortunate cases where such a rock has hit a person and killed them on the spot. No, seriously, it happened, and yeah, it’s rare…but it happened!
In terms of planetary destruction though there’s only one real option: Asteroids. This was the kind of rock that killed the dinosaurs, and NASA (among others) are openly scouting the solar system to make sure that such a space rock doesn’t decide to do a “round two” on the Earth. Believe it or not though, we’ve come close before.
In Russia not too long ago, an asteroid entered our atmosphere and exploded in the air about a forest in the country. The shockwave shattered windows from cities miles away, and the fires of that explosion torched many trees.
Here’s another fun fact, an asteroid that could’ve wiped out the Earth was once only hours away from hitting us. The Earth was out of position, but if that rock was just a little quicker, or Earth’s orbit just a little slower, it would’ve wiped us out.
So what do you fear in terms of space rocks? Asteroids, that’s what.