Looking at the earth from space, we will find that this is really a very beautiful world. The appearance of the Earth presents a beautiful blue glow, so we call the earth the blue planet.
Why is the earth blue? One of the main reasons is that there are a lot of liquid water resources on the surface. 71% of the earth’s surface is covered by the ocean, while the land area is only 29%. Standing on the earth, you may not feel the huge gap between the land and the ocean, but if you stand in space, you will see it very clearly.
The land for human survival is separated by the ocean, forming five plates. Such a vast ocean makes the earth look like a world of water. Many people call the earth a water ball. So the earth’s water resources in the universe, can also be called a water rich planet?
There are innumerable galaxies and planets in the vast universe. At present, we have no ability to detect the planets outside the solar system. Naturally, we do not know the water resources of the planets in the solar system. But in the solar system, in addition to the eight planets, there are also a large number of asteroids, some of which orbit the planets and become satellites.
Some of these satellites also have a lot of water resources, so how do they compare with the water resources of the earth? Now let’s make a brief introduction to science popularization. When it comes to water rich planets, apart from the earth, we need to focus on several moons of Jupiter and Saturn.
As we all know, Jupiter and Saturn are the first and second largest planets in the solar system. Because of their huge mass, they have attracted many asteroids to become satellites by virtue of their gravitational advantages. Each of these satellites has its own style. Some satellites can be called a world of ice and water.
Let’s take a look at the real water rich planet, Europa. Europa is the sixth known moon of Jupiter and the fourth largest moon of Jupiter. It has a very nice name Europa, which is a mild world.
Europa is only 3100 kilometers in diameter, smaller than the moon, but it is such a small planet that its surface is basically covered with ice. It can be said that it is the brightest satellite in the solar system. The reason why it has such a high brightness is that its surface is completely a world of ice, which can reflect more and stronger sunlight.
Although the surface of Europa is completely covered by ice, its interior is still relatively active, with geothermal energy, thus forming a huge water world under the thick ice. According to the current survey data, the depth of the ocean beneath Europa’s ice sheet may reach about 100 kilometers, which is more than 20 times the average depth of the earth’s ocean.
You know, the deepest part of the earth’s ocean is the Mariana Trench, which is only about 11000 meters, far less than the depth of Europa’s underwater ocean. Although the diameter and volume of the earth are many times larger than that of Europa, our water storage capacity is far less than that of a small Europa.
We can roughly calculate that the total area of the earth’s oceans is about 360 million square kilometers, and the total amount of water is about 1386 million cubic kilometers. It sounds like a lot, but let’s look at the water resources of Europa: the water content of the ocean has reached 2.8 billion cubic kilometers, and the total amount of sea water is about 1.386 billion cubic kilometers, which is more than twice the total amount of water resources of the earth.
It’s incredible that a satellite whose diameter is not as big as the moon can store more than twice as much water as the earth. If all of Europa’s water is poured on the earth, the earth’s sea level will rise at least 5000 meters. At that time, there will be basically no land except a few peaks.
After watching Europa, let’s take another look at another moon of Jupiter, Callisto. Callisto is the second largest moon of Callisto. Its diameter is about 99% of that of mercury, which can be regarded as a relatively large satellite. Although the diameter of Callisto is the same as that of mercury, its mass is only one third of that of mercury. The reason is that Callisto is basically composed of the same amount of rock and water.
Although the surface of Callisto is not completely covered with ice like that of Europa, the amount of water on it is more than that of Europa. Galileo’s exploration results show that there may be a small silicate core inside Callisto, and there may be an underground ocean composed of liquid water 100 kilometers below the surface.
After introducing Callisto, let’s take a look at Jupiter’s largest moon, Ganymede, which is also the largest moon in the solar system and larger in diameter than mercury. Ganymede is also a planet with much more water resources than the earth. It is mainly composed of silicate rocks and ice, and its surface is also covered with a lot of ice.
Ganymede is the only known satellite in the solar system with a magnetosphere, which may be caused by the convective motion of an iron rich flowing core. With the existence of the magnetosphere, it also formed a thin layer of oxygen-containing atmosphere. The probe found that Ganymede was rich in various organic compounds on the surface, and at the same time, magnesium sulfate, sodium sulfate and other substances were also found.
These important findings indicate that there may be a huge ocean world beyond the surface of Ganymede, and even life. In addition to these moons, Pluto and Triton are also ice worlds, and there may be liquid oceans under the thick ice, both of which have more water storage than the earth.
The two satellites, Enceladus and Titan, also have abundant water resources, but they can’t compare with the earth. Through the above introduction, we can see that even in the solar system, the earth is not a water rich planet, there are many more than its water rich planets.
It also shows that water is not a rarity in the universe, as long as it is not particularly close to the main star, then it is easy to enrich a lot of water resources. Even out of the habitable zone, the water on the surface turns into ice, but due to the existence of geothermal energy, there is a great probability that a rich underwater ocean will be formed under the thick ice.
There are so many water rich planets in a small solar system. If we look at the whole galaxy and the whole universe, there may be so many water rich planets that we can’t believe it. Water is the source of life. It is precisely because of the rich resources on the earth’s surface that life has been bred, the continuous evolution of life, and finally the birth of intelligent human life.
Because of the abundant water resources, the solar system can give birth to a life planet earth and human beings. Then, other star systems in the universe may also give birth to one or more life planets. If we are lucky enough, this life planet can continue to evolve, and finally intelligent life and civilization will be born.
Even in the solar system, scientists also believe that life may have been born on the water rich planets and in the subglacial oceans. However, due to the limited scientific and technological strength of human beings, we have no way to enter the exploration. Perhaps in the near future, human probes will be able to explore the subglacial oceans of several moons of Jupiter and Saturn, looking for traces of extraterrestrial life. We are looking forward to that day.