How Did The Solar System Form?

The birth of our solar system is a very important talking point in the grand scheme of our universe. But how exactly did everything in our universe form? Join me as we explore the creation of our solar system.

The Big Bang

In the beginning…there was nothing. Or at the very least that’s what most people tell themselves, it’s very hard to determine what really was, or wasn’t, at the beginning of time, but regardless of what was there before, there is little doubt in the minds of many that a great “explosion” happened in the “center” of the universe. Mainly that there was a an explosion of energy and matter that moved out in all directions, and that it was through this explosion that the birth of the universe came. This is known as the Big Bang Theory, and it’s one of the most debated and researched areas of science today. Mainly because while many scientists think about how this could be, and how it makes sense that the Big Bang happened, others aren’t so sure.

After all, how could such an explosion happen? And by that toke, if it happened once billions of years ago, why hasn’t it happened since? According to scientists our solar system is over 4.6 years old, so why hasn’t another Big Bang happened since then? Another problem is how the universe itself was formed, if it was all a random expansion of matter and energy, then why is it that only Earth has life on it that we know of?

These and many more questions are what make the Big Bang Theory such a massive debate, but lost in the shuffle is one of a much smaller scale. Mainly, the scale of our own solar system. Because even if the Big Bang did create the universe, you kind of have to wonder just how our own solar system got made. What events led to everything being like it is right now?

What Came First and How?

Depending on who you talk to, the events of the Big Bang are much different than you would think. Some think that they explosion of energy and matter allowed planets to be formed near instantly (though admittedly not in their “final form” as we know them now), while others believe that the process of forming the planets and stars took a lot of time and events to happen.

The latter option is what we’ll be discussing today, because one of the most prominent theories and beliefs about how our own solar system came to be was not that it happened near instantly, but that it came from a series of events that led to the slow and methodical construction of each of the nine planets in the solar system. It’s known as the “Solar Nebula Theory”, and it’s one that is backed up by certain sciences.

To put it loosely, the Solar Nebula theory states that when our particular section of space was made (focusing on our own solar system and not the larger galaxy) there was a massive volume of gas that just loomed around. It apparently was so large that it measured 100 astronomical units in length. For the record, 1 AU (astronomical unit) is the distance between the Earth and the sun, which is 93 million miles away for the record. So now imagine a massive cloud of space gasses, dust and molecules that is 930 million miles across. It was from this that came our solar system, although it obviously didn’t look like that to begin with.

So through this cloud, everything started to form. But…what exactly was the first thing to form? Well, what’s the center of our solar system? That’s right, it’s the sun, and that was the first domino to fall.

The Sun

Ok, so apparently there is this giant mass of space cloud hovering where our solar system is supposed to be, right? But how does it go from a massive cloud to a bright ball of warmth and energy we call the sun? Time, pressure, and a little bit of luck.

Most scientists who believe in the Solar Nebula theory understand the concept of the cloud being there and then somehow starting to make the planets and the sun But what many aren’t sure about is the actual ‘event’ that led to it folding in upon itself. Meaning? Meaning…there isn’t a giant cloud of dust and such right outside our planet, right? Something had to trigger the cloud to compress, to fold in on itself to make things that wasn’t just gasses, and no one is really sure how that happened. Some think it was the byproduct of a nearby supernova, but it’s all just speculation.

What we do know (or at least can theorize) is that when this started to happen, when the Solar Nebula started to destabilize, it compressed upon itself, and when you have a massive thing of gas folding in on itself, things tend to get massive.

And as the cloud began to compress, it also started spinning, until eventually there was a giant pancake disc spinning around in our solar system. Not exactly a sun, but a big step in getting there. In fact, most label this as a “Protostar“, and when that happened the sun was born…right? Not exactly. We talked about in this post.

Because while it was a protostar, it was still a pancake. It’s estimated that over the next 50 million years that the sun slowly gathered more mass and more energy from the cloud. Likely due to its spinning nature and the gravity it was exuding. Eventually, once it got enough mass and energy, the process of nuclear fusion began in the sun, and that led it to being the big ball of light and “fire” that we call the sun. 

So a major piece of our solar system had been made. But…there was still a few more things that needed to be done to be complete.

How The Planets Were Born

So at this point in our solar system, the sun is out there in the center of it (in terms of how we think about it anyway) and clearly things are going well. But what about the planets? How did they come to be?

Not so ironically, the same way that the sun was made, just with a lot less fire and such. Because while the sun was going and starting to form, the Solar Nebula was still reaching out in all manners, and the sun wasn’t the only thing forming when it was starting to collapse. Through this process, a lot of things were literally just “thrown together”, and it made not just the planets, but comets, asteroids, moons, and many other things that you can find up in the sky.

It wasn’t a “grand creation” by any means, it was more of a “throw it together and see if it sticks” kind of thing, you know?

This is one of the reasons why there are so many objects in our solar system, and why there are so many different kinds of planets. Some of the planets are gas giants because that’s all they had to work with (or they had solid dense cores and the gasses just run to that) and when they were big enough and such, regular matter like rocks and stuff couldn’t stick to it. In contrast, planets like Earth, Mars, and Pluto were able to go and be solid because of the matter that was around them. The gasses of the nebula were start a part of them, but they were absorbed either into the ground or into the very atmosphere itself.

The further away from what would be the sun they were, the colder they got, while the closer they were, the hotter they got.

So thus the planets were formed and everything lived happily ever after, right? Yeah…not so much.

Solar System Blitz

I want you to imagine you’re playing a game of jacks. You know, where you lay out all of the spiked objects, you bounce a ball and you try and pick up as many as possible in one bounce? Yeah, that game. Now, I want you to picture yourself about to drop the jacks onto the floor you’re playing on. The act of you dropping them is the Big Bang, and how they stay once they stop bouncing around is the formation of the sun and planets.

Right now, everything is fine, because there’s plenty of space between them, right? Or at least enough space so that they don’t go bouncing off one another. Now though, picture that gravity started to be exerted on them in such a way that they started to move. And not just move in an orbit, but move in such a way that they start crashing into each other. What do you think would happen to the jacks? Exactly, they’d get injured, they’d get broken, and so on and so forth.

That’s technically what happened when everything started to get fully formed. On one hand, you had the sun, which was exuding such an intense gravity that everything started to orbit around it. Then, you had the planets, which had their own gravity, and they decided to try and pull objects to themselves.

As if that wasn’t enough, when the sun went nuclear, it created solar winds which went and pushed just about everything out of the way of the sun and thus sending it careening around the solar system. This “blitz” if you will caused a TON of collisions, which meant that a bunch of planets, moons, and other bodies were damaged.

In fact, it’s believed that one such event caused the creation of Earth’s moon. Specifically a chunk of Mars crashed into the Earth and ripped a piece of the planet out that made the moon eventually.

This kind of construction went on for many, MANY years, and it technically still goes on today, though admittedly at a lesser scale and a lot less frequently. The end result once the dust had cleared was that there were many moons or satellites (in regards to space junk not the man-made object) orbiting various planets, and things were stable enough to where the solar system was as it is right now.

So is that it? No…we still got some things to do.

How The Planets Were Born…Part 2

So at this point in time, the universe is starting to settle down, and our solar system has the shape and orbits and structure that we know it has now. More or less anyway, we’ll be fair on that count. But the point is that there are a lot of things that feel familiar, but that doesn’t mean that everything is done, far from it.

At this point, the planets are mostly formed, but that doesn’t mean that they look exactly how they do right now. Earth most definitely isn’t lush and green, Mars likely isn’t the red planet yet, and Venus more than likely isn’t a gas-filled sauna that’ll melt your skin off.

It was over the course of millions of years that the planets subtly changed into what we have now. Mars got a whole in its atmosphere, took all the water out of it, and thus left it a red wasteland. The heat of the sun mixed with the gasses in the atmosphere turned Venus into a greenhouse planet. And as for Earth, we were nothing but barren rock before things started to truly form. Many speculate that the excess hydrogen from the Solar Nebula was absorbed into the mantle of the Earth, and that helped create the water that we have in our oceans and lakes (with the help from asteroids and such carrying their own water and bringing it to the planet).

Time moved on, and things started to grow on Earth, until eventually life formed, and through the course of millions of years that life evolved into what we have now. For that, we should be eternally grateful.

The Luck of Earth

So when you think about it as a whole, the Earth is truly lucky. No, really, think about all the events that had to take place for the Earth to be made, or even as a grader scope what it took for the whole solar system to be made. Think about all the elements that went into making the solar system as we know it now, all the things that the planets had to survive in order to be what they are now, and everything that had to go right for them NOT to be destroyed.

In the Earth’s case, it was almost destroyed by the collision that helped make the moon. So yeah, we got lucky on that one.

Going even deeper than that, the Earth got lucky in how it was able to make life. It’s perfectly positioned in regards to the sun that it gets heat, gets light, yet it isn’t harmful to us on Earth outside of a few special circumstances. We don’t get bombarded with tons of radiation, the heat doesn’t burn us instantly, and on and so forth. It’s quite a miracle we’re alive to be honest.

Which brings us back to the Big Bang and Solar Nebula theories. Because given all the “work” that went into the making of the universe and our solar system, is it truly possible that we were so lucky in the process of events that all of the creation on Earth happened…randomly?

It’s true that a random chance is better than no chance, but could the universe really have struck that many lucky hits in a row?

No one really knows, and thus the debate continues. But no matter what the answer is, the results are the same. The solar system is here, and we’re a big part of it.