Where Did Earth's Water Come From?
313The creation of our planet raises a lot of questions, but there's one you might not be thinking of. Mainly, where did all the water come from? Join us as we explore where and how the water on Earth came to be.
8. In the Beginning...
So to truly answer this question, we need to go back to the literal birth of our universe. "But why is that?" you ask, "wasn't Earth always filled with water?" The answer to that is a bit tricky. Because it depends on what you believe in regards to the creation of the universe. By that, I mean, if you believe in creationism, or the belief that there is a god or gods that created the world and universe, then the answer would be no...but the waters came quickly after the "formation" of the world.
However, for those who believe in the Big Bang, then it's very logical to understand how the world was NOT born with water, because the boom of energy that created our solar system and put everything in its place and orbit would not have created water. Or at the very least wouldn't have created the liquid that we know from now on Earth.
Which of course raises the question of...where did all the water come from? Because it most certainly didn't just "appear", and as our planet is basically 2/3's water, it would've needed to be built up a lot over time, even if that "time" was billions of years. Which is accurate to an extent as we know that have been creatures living in the water for billions of years according to scientists, and many even suspect that live was born in water and not on land.
While the search for the "birth of water" may not be what's taught in history books and in grander discussions of the universe, it doesn't mean people aren't trying to find the answer. In fact, some people they have "found" the answer, and it's via something that is very near and dear to the hearts of many planets...space rocks.
7. The Rock and Water Invasion
So if it's true that water wasn't just born on Earth, then it had to have been created on the planet, or infused on the planet by some outside force. On that account, scientists do agree that over the course of millions and billions of years that meteors, comets, and asteroids hit the Earth, and when they did, they infused the ground with water. Add numerous rocks crashing down over the years and millennia and epochs and all that and you get a large body of water.
I'm sure this somehow seems far-fetched, I would even go so far as to say that some of you didn't know that asteroids and the like carried water with them. But they do, and we do know that they helped bring some of the water to Earth. How so? Isotopes. Specifically, the isotope of Hydrogen. Even more specifically than that, the version of Hydrogen isotope known as deuterium. The Earth's water has a certain concentration of deuterium, and that concentration matches the waters that have been found and studied in asteroids and comets.
But wait, there's a catch, while much of Earth's waters seem to have been created by asteroids, there are a few inconsistencies, and so many scientists are actually debating whether the asteroid/comet theory is fully accurate.
"It’s a bit of a blind spot in the community. When people measure the [deuterium-to-hydrogen] ratio in ocean water and they see that it is pretty close to what we see in asteroids, it was always easy to believe it all came from asteroids." said one scientist
But that begs the question, why don't they believe it all came from the asteroids?
6. The Shape Of Water
Ok, I couldn't resist that title, I do apologize in advance. *ahem*
Seriously though, the question of why the asteroid theory doesn't work is an important one. Mainly because the asteroid theory works as a plausible method for how the water on Earth came to be. With the exception...of one question. How is it that the Earth was hit by SO MANY asteroids, comets, and such to where 2/3's of it were covered by water?
No, really, think about it, the Earth isn't just covered in water, it's covered in water that is tens of thousands of feet deep. One of the deepest points in the ocean is the Mariana Trench at over 36,000 feet in depth, and it really does keep going on from there. So add that depth, to 7 oceans, innumerous lakes, rivers, and more, and you get...a whole lot of water.
So how is it possible that there were enough meteors, asteroids, comets, and more hitting the Earth in the beginning part of the universe that it would cause that much water to be made? It doesn't add up for a lot of scientists.
Now again, there's no denying that some asteroid water was brought to Earth, the isotopes prove that. But what some scientists apparently choose to ignore is that the levels aren't always so balanced, and they don't make up for the inconsistencies noticed in that isotope across the world. Meaning that while asteroid water is PART of what made our watery planet, it's not the only thing. And that is a very important distinction.