“The Mystery of the Heat Source” of the “Galileo Satellite”

In the solar system, because Mars is close to the earth and there are likely to be signs of flowing water and life, mankind has devoted the greatest enthusiasm to the exploration of Mars, but Mars is not the only “life planet” in the solar system. Leaving Mars, passing through a belt of asteroids, you enter the cold and gloomy zone of the solar system, where there is a behemoth—the largest planet in the solar system, which is Jupiter.

Jupiter is a huge gas planet, and human beings are not much interested in searching for signs of life on this planet. But around it, 4 huge satellites are very eye-catching. On January 7, 1610, Galileo pointed the telescope at Jupiter. Next to Jupiter, he saw three bright spots, and a few days later, he found the fourth one. These 4 bright spots are the first Jupiter moons discovered by mankind, and they are also the 4 largest moons of Jupiter. They are named Io, Europa, and Europa after the gods in Greek mythology in order of distance from Jupiter. Ganymede and Callisto, namely Io, Europa, Europa, and Callisto. Since these 4 satellites were discovered by Galileo, they are called “Galileo satellites”. According to a latest analysis, the “Galileo satellites” are very special. In addition to obtaining energy from Jupiter with the help of tidal waves, they can also “heat each other” and use the gravitational force between each other during internal friction to obtain heat energy. Increased the chance of surviving life on these planets.

Europa’s surface resembles the frozen sea on Earth.

The “active planet” of the Jupiter system
From the early 1970s to the late 1980s, humans began large-scale Jupiter exploration activities. The United States successively launched four probes, “Pioneer 10,” “Pioneer 11,” “Voyager 1” and “Voyager 2,” to investigate the Jupiter system.

On October 18, 1989, the US “Atlantis” space shuttle sent a probe named “Galileo” into space specifically for detecting Jupiter and its satellites. On December 7, 1995, the “Galileo” probe entered Jupiter’s orbit and flew around Jupiter, and flew to several satellites of Jupiter for close-range detection. So far, mankind has a more in-depth understanding of the “Galileo satellite”.

Among the “Galileo moons”, Io is the closest to Jupiter. Its bright colors are a “volcano kingdom”, and its lava material is 100 times that of the earth’s volcanoes. Europa, which is adjacent to it, is a frozen world with few craters on the surface and covered with smooth and flat ice for many years. Some areas are very similar to the frozen ocean on Earth. Both Ganymede and Callisto are the big men in the moons. Ganymede is the largest moon in the solar system. It is 3/4 the size of Mars and is bigger than Mercury. According to preliminary detection results, liquid salt water may also be hidden under the ice layer of these two satellites.

It is puzzling that the “Galileo satellites” are far away from the sun, so how do these small planets stay warm enough and make the internal matter liquid? For this problem, scientists have reached a basic consensus, and they attribute the cause to the satellite’s planetary host-Jupiter. When orbiting, the mass of this giant planet produces a pulling force or tidal force caused by gravity, which stretches and squeezes the satellite, which in turn causes the internal matter of the planet to generate heat due to friction. As a result, Io’s interior was in a molten state, and the heat flow rushed out of the surface, causing a spectacular volcanic eruption, prompting the internal temperature of the other three “Galileo moons” adjacent to Io to also increase, thus causing the ice crust to rise. The sea water remains liquid.

Heat flow surging under “resonance”
But few people have seriously considered the gravitational squeeze between satellites. In this regard, planetary scientist Hamish Hay of NASA’s Jet Propulsion Laboratory explained: “This is because these moons are much smaller than Jupiter. You would think that basically the tidal force produced by Europa and Europa It’s so small that it’s not worth considering at all.”

In order to study the gravitational squeeze between the “Galileo moons”, Hay and two planetary scientists from the University of Arizona calculated the magnitude of the Tidal force acting on the “ocean” within each other. They found that the importance of tides depends on the depth of the ocean. If the size of the ocean is appropriate, neighboring satellites can push and pull tidal waves to each other at the appropriate frequency, creating resonance. When entering a state of resonance, the tidal wave becomes larger, which is similar to swinging your legs on a swing or shaking a bridge with a neat pace.

Io is very close to Jupiter, so it bears Jupiter’s powerful tidal forces. Not only that, Europa and Europa also form an interactive gravitational relationship to Io: Io’s revolution period is twice that of Europa, and Europa’s revolution period is Europa. Two times three times, the resulting tidal wave makes Io temporarily prolonged and sometimes shortened. The internal friction is generated during the expansion and contraction. The friction generates heat, which causes the matter in the star to be melted and spewed out from the surface to form A spectacular volcanic eruption.

Increased chances of finding life in the universe
The research team found that Europa has the greatest impact on Io. Although Europa is far away from the sun and its surface is extremely cold, the huge tidal forces of Jupiter and Io raise the internal temperature of Europa, thereby releasing heat to keep the sea water liquid.

So, what about Ganymede and Callisto? They are huge, and their influence on Io and Europa is obvious. At the same time, they generate internal vitality in this gravitational relationship. The “Galileo” detection indicated that Europa’s ice layer may also hide liquid salty water with a temperature of -55°C, which is located much deeper than Europa. Due to the high pressure inside the satellite, this liquid water layer did not freeze. Liquid water is an important condition for the existence of life, so Ganymede is also used as a target for people to search for extraterrestrial life.

Callisto is only a little smaller than Ganymede. Its surface is covered with craters, and there may be a salty ocean hidden beneath its surface. However, the inner ocean of Callisto is full of dense ice and rocks, which prevents the flow of heat energy, so the possibility of life on Callisto is very slim.

At present, people’s goal of searching for signs of life in the Jupiter system is mainly locked on Europa, and some exploration plans to enter Europa’s ice layer are also being brewed. The “mutual warming” phenomenon between the “Galileo satellites” shows that some planets have the ability to generate heat energy by their own operation, not necessarily relying on stars, which greatly increases the probability of humans discovering life in the universe.