The famous astronomer Copernicus once said that "man's vocation is to have the courage to explore the truth", and when human beings first looked up at the night sky, they began to imagine the universe infinitely.
Later, with the support of technological development, we have telescopes and satellites, which can replace us to observe the vast universe, and human beings have not only fulfilled the dream of flying to the sky, but also realized the dream of flying to the universe. Countless probes are flying in all directions of the earth, and we are so curious about the universe. In addition to hoping to find traces of life on other planets, we are also searching for the truth of the universe.
Jupiter, as the largest of the eight planets in the solar system, is large, but it ranks fifth in terms of order from the inside out. Jupiter is arguably the brightest object besides the Moon and Venus when we watch the stars at night, and because of its large size, it has many natural moons, and according to 2019 data, the number of Jupiter moons found so far has reached 79.
Among so many satellites, there is a very special, can be regarded as a key object of observation of human beings, and its status is comparable to mars. Although it is smaller than the Moon and only three thousand kilometers in diameter, beneath the thick layer of ice lies a vast "subglacial ocean" that may be larger than Earth's ocean. So are there magical creatures in this ocean?
It has to be said that Jupiter, as the largest planet in the solar system, makes human beings always have some fantastic ideas for its future and mission. First, let's look at the type of Jupiter, which belongs to the Jupiter-like planet and is also a gas giant. The average diameter is 139822 kilometers, the diameter of the Earth is 12756 kilometers, this gap is difficult to imagine that everyone is a good brother in the solar system, it is estimated that Jupiter privately ate a lot of "spinach".
Many people say that Jupiter is a barrier to protect other planets, especially the earth, our blue planet, although it has bred a variety of life, but also the emergence of human beings such a high-IQ creature, but in fact, it is still very fragile. Because Jupiter is large in size, gravity is very large, can attract comets flying inward, so it is like a super protective umbrella or a solar system vacuum cleaner, helping the earth solve a lot of trouble, after all, if there is no barrier, the earth will always be hit by comets The probability will be greatly improved, then the earth is estimated to have become the same as the moon.
Jupiter's English name is Jupiter, which is actually named after the gods of Roman mythology, and its status is comparable to That of Zeus, which is enough to see that people are very afraid of this superstar planet. Because it is a gaseous planet, we cannot determine the boundary of Jupiter at this time, it is worth mentioning that its shape is more elliptical, and its rotation period is also the fastest of all the planets in the solar system, taking only 9 hours, 55 minutes and 30 seconds to turn around, and the orbital period is 11.862 years. In addition, Jupiter's magnetic field is very strong, about 14 times that of Earth's magnetic field.
So why is it said to be the successor of the sun? This is because its composition and structure are very similar to the Sun, and its helium content is almost the same as that of the Sun's outer layer. And as mentioned earlier, it is the third brightest object when we look at the sky at night, not only because Jupiter's apparent magnitude can reach up to 2.94 magnitudes.
According to expert research, it has also found that it has been emitting its own light, and the brightness is also increasing, emitting almost the same energy as the energy emitted by the sun, which seems to indicate that it has the conditions to become a star. Some even say that if the Sun had aged and evolved into a white dwarf after tens of billions of years, unable to provide energy and heat, Jupiter would have succeeded it as the new star of the solar system.
However, it is obviously impossible, after all, the necessary condition for star formation is that the mass is large enough, and Jupiter, although the mass of the planets is the largest, is only one-thousandth of the mass of the Sun, like the red dwarf, which is currently considered to be the smallest star, with a mass of about one-tenth of the Sun.
Discovered by Galileo with a telescope in 1610, Europa is Jupiter's sixth known moon, the fourth largest of them. In addition to Europa,which is simply and rudely named after the ordinal number, it also has a name called "Europa", as everyone may know, unlike the way we use the five elements for the name of the celestial body in China, most of the names given to celestial bodies abroad are taken from the names of mythological characters, such as the English name of Venus comes from Venus, Europa is also a beautiful and gentle woman, and the current name of Europe also comes from her.
With a mass of 4.8 × 1022 kg, a diameter of 3138 km and a volume of 1.593 ×1010 km3, Europa is the second closest of all the moons discovered by Galileo, 670,900 km from Jupiter. From the photos of Europa that came back, it appears that this is a frozen planet with many intersecting linear structures on the surface, which scientists deduce that this structure has caused the material inside it to move due to tidal heating.
Europa as a whole is very similar to an Earth-like planet , consisting of silicate rocks , with a surface covered in water , but frozen to ice at low temperatures. It is not difficult to see from the photos that Europa's surface is very smooth and not as potholed as the moon, so its albedo is very high, and scientists speculate that Europa's surface age is between 20 million and 180 million years, or very young.
In addition, the scientists have built multiple models based on limited data to study Europa's structure. According to the study, Europa's outermost water ice layer may be between 80km and 160km thick, and the surface ice layer is about 10km thick, of course, it is very likely to be much thicker than this. According to the model established by Emden's equation, Europa's core size is around 596 km, and the central pressure is between 48.8 and 55 kbar.
According to data observed by the Hubble Spectrometer in 1994, Europa has a very thin atmosphere on its surface, and the main component is oxygen.
Scientists deduce that Europa's oxygen may be the impact of charged particles and the illumination of ultraviolet rays in the sunlight that cause some of the water molecules in the ice on Europa's surface to break down into oxygen and hydrogen, hydrogen escapes due to low atomic weight, and oxygen with relatively high atomic weight is retained.
Europa's surface temperature decreases from the equator to the poles as the Earth, with an average temperature of -163 °C on the equator and -223 °C at both poles, so the water on its surface should be permanently frozen, but the huge tidal action can provide heat for it, thus providing the conditions for the water below the ice to melt and turn it into a liquid ocean.
There are also fountains above Europa, most of which erupt intermittently, without specific rules, but each eruption lasts about 7 hours. The result was largely discovered in 2005 by the Cassini probe in the United States, where scientists suggested that europa fountains may have been derived from emissions of high-pressure water vapor, in which Jupiter played a key role in Europa's huge tidal gravity, causing cracks in europa's ice surface.
In addition, on December 11, 2013, NASA announced that clay-type minerals had been found for the first time on Europa's surface, meaning that Europa may have organic matter that is essential for the formation of life.
Multiple pieces of evidence point to the possibility of liquid oceans beneath Europa's ice, and photographs from the U.S. Galileo Jupiter probe have shown melting zones in Europa's ice.
In response to this, Stanford University astronomer Christopher Hiba pointed out that this may be caused by the sudden proliferation of marine microorganisms, and that Europa's surface ice, although it does not melt, may have a circular contact with the subsurface ocean every 10 million years or so.
The evidence for the existence of Europa's liquid oceans is mainly divided into the following two categories, the first being tidal evolution and Laplace resonance. Not only does Europa produce thermal energy under the tidal action of Jupiter, but the Laplace resonances of Europa, Europa, and Europa also produce changing tides within it. After all, the Moon has tidal gravity on the Earth's oceans, so Europa's surface ice is not alarming under so many tidal forces, but it does not prove that the material underneath will not be active.
This is followed by Europa's unique surface structure, which has many lens-like structures on its surface that are thought to be produced by the viscous material beneath the surface as a result of buoyancy rising squeezed into the folds. In addition, there are ice volcanoes on the surface, ridges, and fountains we mentioned earlier, all of which can prove the existence of liquid oceans.
The reason why scientists are so concerned about the existence of liquid oceans on Europa is that they stand in the position that "water" is one of the conditions for the emergence of life, and scientists have always believed that the existence of life requires three indispensable conditions: First, the possession of water. Second, there are organic compounds, mainly represented by hydrocarbons. Third, there is a source of energy, such as heat. Europa's current condition fully satisfies these three conditions, so Europa is more likely to have life than Mars.
Extrapolating, scientists believe that the organisms that survive in Europa's liquid ocean may be simple single-celled individuals, more similar to life that arose at the beginning of Earth's formation. In 2009, scientists at the University of Arizona in the United States pointed out that Europa's ocean may have 3 million tons of fish organisms, and their structure is not as simple as the simple single cell mentioned above, but similar to the creatures deep on the earth's seabed.
If according to him, then the mysterious creature seen by Europa I in the science fiction movie Europa I may really live under the surface of the ice of Europa, although it looks like a giant octopus that is glowing in the movie, but it is difficult to say what terrible creatures will be born under that environment, and we cannot yet paint a creature beyond imagination, and can only be inferred from what we have seen in the earth's oceans.
At present, scientists have given four ways to explore Europa's liquid ocean. The first is to simply and rudely bombard it directly with a missile, causing the spacecraft to fire a missile as it approaches Europa. The bombardment of the missiles can cause fragments of ice on Europa's surface to fly high into the air, and then the spacecraft collects the crushed ice. The second is to use spacecraft to approach the probe, and the United States said the Europa Clipper will launch around 2023 to collect more details on Europa.
The third is to let the probe land, just like China's Chang'e 5, according to the calculation of observations, let the probe melt the surface ice after landing to collect data. The final one is to develop a special robot that will drill holes in the surface after landing and extend the detection equipment underwater.
You can go to see the "Europa Report", this film is based on people's observations and conjectures about Europa now, although the "glowing octopus" looks a little unusual, but the dedication of the characters can cause us to be touched.
Confucius said: "When you hear the Tao, you can die at night", which probably represents these people who tirelessly explore the universe, whether they are conscientious scientists on the ground or astronauts who fly into space to put life and death aside, in essence, they are "martyred" for exploration. Human beings have fragile bodies, but they have incomparably strong beliefs, inexhaustible curiosity will push us deeper into the universe, and the mystery of Europa will be solved sooner or later.