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When you look at the Earth from space, it is blue, so some people call it the "Blue Planet", but when you stand on the ground, it is difficult to see where the "blue" comes from.
Could it be that this small property of blue also allows us to distinguish it visually?
So how much "blue" is there on the surface of the earth?
Except for the ice caps of the Arctic Ocean and Antarctica at high latitudes, the rainwater flowing in the Amazon rainforest, and the many lakes on the continent, most of the places really don't see blue, mostly composed of green, yellow, brown and other colors.
So why isn't the Earth called "water ball"?
So if it's not called a water balloon, which celestial body should be called a water balloon?
1. "Blue Planet".
There are many forms of water resources on the earth, such as oceans, lakes, rivers and glaciers, among which the ocean has an absolute advantage.
So the earth is indeed blue from space, because almost most of the earth is covered with seawater, and of course there are a lot of plants mixed with the earth's surface material, so the blue is not so pure.
If you want to say that the largest ocean on Earth is, the Pacific Ocean is certainly the largest, it is larger than the world's largest landmass Asia, covering an area of 179 million square kilometers.
There is also a version that the Atlantic Ocean is larger than the Pacific Ocean, but this is already very large, just like Asia has the Asian continent, Asia not only has continents but also oceans, so the Atlantic Ocean is just the size of the Atlantic Ocean, and the Pacific Ocean should be called the Pacific Ocean.
No matter which version you believe, the combined area of the Earth's oceans reaches 360 million square kilometers, covering 71% of the total area of the planet.
In other words, the Earth's land area is only 29% of the Earth's total area, but it is the main area where the world's population lives and produces.
So from this point of view, why is this "blue planet" not called "water ball".
In fact, the planet Earth also has the nickname of "water ball", that is, the "blue planet".
In many science fiction works, it appears under the name "Blue Planet", but more often it is used to distinguish it from other planets, such as Mars, also known as the "Red Planet".
2. Which planet should be called "water ball" the most?
Who came up with the name "Earth"?
This man is so imaginative, why didn't he give it a very creative name, but just called it "Earth"?
In fact, the word "earth" first appeared in the "Astronomical Chronicles" written by Zhu Yizun of the Ming Dynasty, and the meaning of earth also refers to the earth.
The name "Earth" refers to what you see when you look down on the Earth from space, that is, when you stand in space relative to the Earth.
As a celestial body, the earth refers to its own star, the planet in the solar system, and the name "sun" was first born in astronomy during the Han Dynasty, and scholars in the Han Dynasty gave it the name "Sun and Moon".
So needless to say, everyone also knows that the scholars of the Han Dynasty only named it according to astronomical phenomena, and they asked everyone to call it "sun", in fact, it can be seen that these scholars have long recognized the existence of the sun as a star.
This lets us know that these scholars have a high level of research in astronomy and let them name them according to what they see.
The name "Earth" was named by Zhu Yizun, how to explain this name?
Is the name used to look at the earth in this direction, like the "sun"?
Is the name "Earth" the same everywhere?
The name is the same from any direction, but the "sun" is not like that.
And is the name "sun" the same everywhere?
"Sun" simply refers to the star we are on, and the Sun will be more specific than the name "Earth".
There are many other suns in the universe, but the closest sun to us is the "sun" we see.
But the name "Earth" is different, there is only one "Earth" in the universe, and there is only one "Earth" that we see.
So in fact, the name "Earth" is not simply used to refer to the planet Earth.
3. Why is the earth not called "water ball"?
Europa orbits Jupiter, the fifth planet in the solar system where the Earth is located, and it is also the largest planet in the solar system, with a mass 318 times that of the Earth, and Europa is about 80 million kilometers away from the Earth.
But what kind of moon is Europa?
Europa is a combination of rocks, ice, and other materials, and it faces the temperamental Jupiter, which forms a mutually embracing motion.
In this way, Europa also cruises with Jupiter in the sun's rays, and of course, Jupiter's gravitational pull also causes Europa to form an elliptical orbit.
The presence of a large amount of water on Europa is related to the environment in which it is located, and Europa may have had a large amount of liquid water in the early days of its formation, just like Earth.
However, in the early stages of Europa's formation, it faced a bit more pressure than Earth, mainly because Jupiter and Europa, which are more massive than Earth, have a long phase cycle, so the pressure will be very high.
And if these pressures are applied to Europa, then the pressure it faces must be very large, as if a brick is placed on a piece of cloth, and the cloth will be compressed to a certain extent.
But the cloth is not a piece of iron, so if the pressure is higher, the cloth will be crushed.
If Europa were exposed to more pressure, the liquid water would turn into a solid state, but this is not the case on Europa.
The liquid water on Europa is most likely found beneath a thick layer of ice below Europa's surface.
Just like the frozen Antarctic regions of the Earth, there are many oceans and lakes on the Earth, but no deeper oceans have been found than these regions.
The ice on Europa is the same as the frozen Antarctic region on Earth, they have huge glaciers on it, and these huge glaciers are probably formed in the interior of Europa, so there is an ocean under the ice.
Unlike the Earth, the Earth's oceans maintain a fixed temperature throughout the year, so the oxygen in the seawater is absorbed by the same oxygen gas as the oxygen in the air.
But the ocean on Europa is different, it changes periodically, when it is closest to the sun, the sunlight melts the ice on the surface, forming liquid water, but in winter, the liquid water becomes solid.