The moon is 238,855 miles away from Earth. If you drove non-stop at 75 miles per hour, it would take you 3,185 hours. That’s almost 133 days. And a drive at the same speed to Mars? If you left today, you might just make it there in a little under 143 years. So yeah, things in space are very far apart, especially using the speeds we are accustom to here on Earth. But the question is, just how big is space? How far away are we from the stars we see in the night sky? The short answers? Very big and very far. Let’s take a quick look at 7 examples of how big, how fast, and how far away things in space really are.
1. The Speed of Earth
For those who are unaware, as we sit on our phones or computers reading this article, we are hurtling through space at speed that make a new sports car look like a beat-up jalopy, except it’s like, exponentially worse than that. Currently, at the equator, Earth is spinning along on its axis at a brisk 1,037 miles per hour. That’s pretty quick, but this is Earth; we can do better. How about our orbital speed? As we all know, a year is the length of time it takes for Earth to complete one full orbit around the Sun. The Earth’s orbital speed? An even brisker 67,000 miles per hour, or 19 miles every second. Now we’re talkin’. But what about the speed of the entire solar system? Oh yes, the entirety of our solar system orbits around the Milky Way. One round trip of our galaxy, known as a cosmic year, takes about 225-250 million years. So how fast does our solar system need to move in order to scream around the galaxy in only 250 million years? The answer is a cool 492,000 miles per hour. That’s about 137 miles per second. Now that is some serious speed. Quick summary: Earth’s rotates on its axis at 1,037 miles per hour while orbiting the Sun at 67,000 miles per hour while the solar system orbits the Milky Way at 492,000 miles per hour. If you thought Earth’s rotation was fast, though, wait until you read about this next example.
2. Neutron Stars
Neutron stars are, on a cosmic scale, very small in size. With a radius of a little over 9 miles, neutron stars are no bigger than an average city. But the point of this list isn’t to show how small things are, right? Well, even with their cosmically minuscule 9 mile radius, neutron stars typically have a mass 1.5 times greater than that of the Sun. If you were out in space near a neutron star (BAD idea) and you decided to scoop a teaspoon of neutron star material, that teaspoon would weigh ten million tons. Neutron stars are so dense that protons and electrons simply cannot exist separately, causing them to fuse into neutrons. Oh yeah, and these things spin. Fast. Like, mind-numbingly fast. When they really get ramped up, some of the faster ones can reach speeds of 600 rotations per second. And we won’t even get into magnetars, a subclass of the neutron star. A teaspoon of a magnetar would be about 100 million tons. Those are different beasts entirely. Anyways, speaking of stars…
3. The Mass of the Sun
It’s a known fact that the Sun is huge and is very far away from us. I mean, we had to create an entirely new unit of measurement, the Astronomical Unit (AU), to measure the distance from us to the Sun so that the number could be contained. So the question is, how big is the Sun? Well to start, the Sun is 109 times larger in size than the Earth. We will get into size scales later in the list. For now, let’s look into the mass of the Sun. To list the Sun’s mass would fill much of this page with an incomprehensible number. We know the stuff in our solar system. We have 7 other planets (sorry Pluto) including the behemoths that are Jupiter and Saturn, we have moons, asteroids, among many other things. The Sun accounts for 99.86% of the entire mass of the Solar System. 0.14% of the solar system’s mass encompasses everything else that isn’t the Sun. Furthermore, Jupiter is 2.5 times more massive than all of the other planets combined. And for Jupiter mass in pounds? Roughly 4.1847 x 10 to the 27th power. A 10 with 27 zeros. Yikes. Let’s scale the enormity down, shall we?
4. A Basketball-Sized Sun
What if the Sun was the size of a basketball? A question that I’m sure many of you have asked yourselves at some point. Ok, maybe not, but now that the question is proposed, my hope is that you are wondering what the answer is. On this scale, one foot is the equivalent of 1,000,000 miles. So we have taken all that size from the previous example and reduced it to this. But this example isn’t designed to show size with regards to mass, but more so the overall size in appearance, as well as the incredible distance between stellar objects. On this scale, the Earth, containing everything we have ever known and loved, would be the size of a pinpoint. Even at such a small size, this scale still leaves us at nearly half a mile, approximately 2,500 feet, away from our basketball Sun. If that bit of information isn’t enough, then let’s ask how far away would the nearest star be? Alpha Centauri, on a scale where a foot equals one MILLION miles, would still be about 4,300 miles away. For a better idea of how far away that is on a regular scale, there are 5,280 feet in a mile. Alpha Centauri would be 4,300 miles away. And every foot equals ONE MILLION MILES. Did I mention that scale enough? Safe to say, that’s a pretty good distance away. But what if we shrink the Sun down even further than just a basketball?
5. A White Blood Cell-Sized Sun
White blood cells are small. Very, very microscopically small. If you placed a white blood cell on the tip of a pin and magnified it, the pin would appear to be the size of a pencil. So now that we know how massive the Sun is, as well as the scale of things if the Sun were the size of a basketball, we can use both of those examples to picture this. The Sun is the size of a white blood cell. 99.86% of our entire solar system’s mass, shrunk to the size of a microscopic cell. On this scale, maybe now we could get an idea of the size of our galaxy. So, with our white blood cell-Sun, how big would the Milky Way galaxy be? The size of Rhode Island? Absolutely not. The size of New York? Still cold. Ok, how about the size of the largest state in America, Alaska? Not. Even. Close. In order to really drive this home, I’m going to have to get a little repetitive, so I apologize in advance. If the Sun was shrunk to the size of a microscopic white blood cell, then on the same scale, the Milky Way Galaxy would be the size of the entire continental United States of America. And that’s just our galaxy. What about the other hundred BILLION galaxies of the universe? Yeah, let that one sink in. And then I’ll tell you about the galaxy that is currently headed directly at us.
6. Our Neighbor, Andromeda
At just over 2.5 million light-years away, Andromeda is our closest neighboring galaxy. Home to nearly one trillion stars, it dwarves the Milky Way’s measly 300 billion star count. This specific example is one of my personal favorites as far as examples of the universe’s vastness are concerned. To start, Andromeda and the Milky Way are going to collide, and it is going to be absolutely epic. Unfortunately, for those star-gazers out there, the collision process with our neighbor won’t begin for quite some time. So, how fast are we speeding towards each other? And how long will it take? Andromeda and the Milky Way are racing towards each other at about 68 miles per second; a pretty good clip. Now for my favorite part. Traveling towards each other at 68 miles per second, how many years will it take for our closest neighboring galaxy and us to collide? 3.75 BILLION years. 3.75 billion years straight of traveling 68 miles per second will bring us and Andromeda to a collision. There really isn’t a scale to bring this to for us to accurately wrap our heads around these numbers without it being obscurely small. The best I can do is to picture driving 68 miles per hour on the highway, then imagine traveling that distance every second for nearly four billions years. Yeah, doesn’t really help. Now finally, let’s bring speed, size, and distance together. It’s time for the entire observable universe.
7. The Observable Universe
Ok, if your brain hurts at this point, I understand, and I am sorry. But it’s all been building up to this. We’ve read about the speeds of our planet, our solar system, and our entire galaxy. We’ve read about the size of our Sun and our galaxy. We’ve read about the distance between us and our nearest celestial body, star, and galaxy. Now let’s expand, quite literally, as far as possible. One light year, which is how far light can travel in a single year, is 5.9 trillion miles. The speed of light is the cosmic speed limit; anything that travels faster than light (which is impossible) would break causality, which, in essence, means effect would happen before cause. Yes, time travel. Also impossible. Entropy cannot be reversed. ANYWAYS (saving that for a future post), the speed of light in a vacuum is 186,282 miles per second, an important figure to remember when discussing the size of the observable universe. Now, since the universe is 13.8 billion years old, one would assume that the observable universe would be the same size, as light has only had 13.8 billion years to travel. However, that is not the case. It is way more complex than that. Without going off a super-boring tangent, the observable universe is much bigger than 13.8 billion light years. The number is more like 92 billion light years, thanks to space expanding faster than light. I know I just said faster than light travel is impossible, but this is the one exception (please don’t ask). Because of space expansion, light from near the beginning of time has had to travel further, hence the 92 billion number. To put that number in some form of perspective, light travel at 186,282 miles per second would take 92 billion years traveling at that constant speed to reach the other side.
What’s crazy to me is that amongst all the vastness, the entire expanse of the universe, we don’t use that cosmic perspective for better here on Earth. Things are so much bigger than us, yet we find ourselves embroiled in war, crime, and hate on multiple different fronts. One of my favorite quotes ever comes from Edgar Mitchell, who was an Apollo 14 Astronaut. He said, “You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch’.” And he only went to the moon. Just wait until we can venture further. Anyway, if you made it this far, thank you SO MUCH for reading as always, and if you have anything you’d like to add, drop a comment below!