In February 1997, the photos taken when Galileo flew by 586 kilometers from Europa showed that the largest iceberg on Europa's surface was 13 kilometers wide and 100~200 meters high. American scientist Steven and others believe that due to Jupiter's gravitational pull on Europa's inner core, the water under Jupiter's ice mantle remains liquid and becomes an ocean several kilometers deep. Photographs taken by Galileo in December 1998 show an 800-meter-long crack in the southern part of Europa.

In January 2000, when Galileo passed 351 kilometers from Europa, it discovered that Europa's magnetic north pole was moving frequently. Scientists believe this is the result of an electromagnetic field formed by Europa's saline ocean flowing under the ice.

After studying photographs of Europa's surface cracks, in September 2002 the Greenberg team declared that Europa ice is thin and that observed surface cracks can expose gases, heat, and organic matter to water that may exist beneath the surface. This situation suggests that Europa's possible oceans are similar to Earth's Arctic Ocean. Since the Arctic Ocean can contact air and heat through cracks in the ice, the ocean on Europa can also contact the outside world through cracks in the ice.

The first global geological map of Europa, based on data obtained by Voyager 2 and Galileo, in 2007, revealed that the surface of Europa was relatively young and varied. In 2008, scientists discovered that Europa's polar axis of rotation shifted by more than 80 degrees. Such extreme changes indicate an inconsistent thickness of the ice crust on Europa's surface, with a vast ocean beneath it. Scientists have also used photographs from a variety of spacecraft to create images of large arc-shaped basins with a surface diameter of more than 500 kilometers on Europa. After comprehensive analysis and research, scientists believe that Europa has a metal core inside, a stony crust outside the core, an ocean of liquid water outside the shell, and ice on the surface of the ocean.

Because water is an important condition for life, scientists deduced that there might be life in Europa's oceans after discovering that there might be an ocean on it.

After Voyager discovered in 1979 that Europa had a wide range of curved brown stripes on its surface, some scientists thought that this meant the presence of organic molecules on the planet, as many organic polymers are brown. At the same time, for the possible ocean, the environment can sustain the survival of organisms, so it is estimated that lower organisms such as bacteria may be alive on Europa.

In August 1996, American scientists proposed that there could also be volcanoes at Europa's bottom of the ocean, and that their eruptions provide enough heat to survive certain microorganisms that do not need sunlight and air, a thesis known as Europa's life hypothesis.

Underneath the Europa ice is water, abundant heat, and organic compounds, three essential elements of life, and the environment is likely to meet the standards of cosmobiology. Primitive microorganisms thrive in the extreme harsh natural environment around some volcanic craters in the depths of the earth's oceans, without sunlight and oxygen, because these places have the above three conditions. Scientists who proposed and endorsed Europa's hypothesis of life believe that its life forms can only be low-level marine organisms based on environmental conditions.

These scientists believe that life on Earth originated from volcanic vents in the ocean, and this principle also applies to Europa. They speculate that Europa also has volcanic activity inside Europa due to Jupiter's gravity. When Europa flies from one side of Jupiter to the other, Jupiter squeezes Europa, causing the latter's core to be in a molten state, causing volcanic activity.

Although the volcano does not erupt on the surface, it heats the water beneath the ice, making it liquid and forming an ocean. Because Io is closer to Jupiter, it is squeezed even more, so the volcano erupts from the surface, leaving sulfur and other chemicals behind. There are also many similar compounds at hydrothermal vents on the Earth's seafloor and are related to early life on Earth. As a result, scientists theorized that Europa's undersea volcanic activity would also erupt similar compounds and create a warm environment that would give birth to and survive life.

The specific goal of mankind to find extraterrestrial life is Mars in the first place, and Europa in second place. How can space technology be used to unravel the mystery of Europa's life? Scientists have proposed four possible solutions.

One is to use ** bombardment sampling:

Humans will launch a spacecraft from Earth to Europa, and when it flies near Europa, it will launch a ** at the right time, violently bombarding the surface of the target, causing ice fragments to fly high into the air, and then the spacecraft will pass through the cloud of ice that has exploded, stretch out the "gel" to collect part of the broken ice, and transport it back to Earth for scientists to study in order to determine whether there is life information.

The second is to use spacecraft for near-space exploration:

NASA and ESA are working on a probe called Europa Jupiter Mission, which is scheduled to launch in 2020 and reach the exploration area in 2026 for a three-year period. The probe consists of two orbiters. The United States is responsible for the Europa orbiter, which carries a camera, spectrometer and a powerful radar system.

When it enters an orbit around Europa, the radar system can penetrate Europa's ice and calculate its thickness, and other instruments will study for signs of marine life. It will help scientists narrow down the range of areas where life may exist, providing a basis for future explorations. ESA would be responsible for orbiters with cameras, spectrometers, dust analyzers, mass spectrometers or magnetometers, which would focus on the exploration of Jupiter's moons.

The third is to use spacecraft landing detection:

Russia will participate in one of ESA's space research programs from 2015 to 2025 in order to land on Europa in search of simple life forms. The spacecraft of this project was named after the French astronomer Pierre Laplace. Russia will develop a landing probe to be carried on board the spacecraft. The landing probe will land on a crack in Europa's surface ice, melt some of the ice, and begin searching for traces of life, which will then be transmitted back to Earth via the Laplace spacecraft.

The fourth is to use robots to drill into the ocean for exploration:

The plan is to launch two landing robots to Europa, one that can drill through the ice to create a channel to the ocean, and the other that can follow the channel into the ocean to carry out exploration work. The underwater robots carry scientific instruments that can orbit and identify microorganisms, including life forms that are different from those on Earth. The results of its detection will be sent back to Earth in due course. In order to ensure that the detection effect was not affected by anything other than Europa, the two highly automated robots had to be completely sterilized.

The significance of detecting Europa's inlife is that, in addition to figuring out the truth, it can also verify or revise the criteria of cosmobiology. If life is found on Europa, it proves that cosmic biology standards apply at least to solar system bodies. If the inferred conditions are true and no life is found, this criterion needs to be amended. If the inference condition does not exist, it is a different matter. Whatever the reality is obtained, it can deepen mankind's understanding of Europa and the celestial bodies of the solar system, and promote the development of space science.

Of the eight planets in the solar system, Jupiter is the largest. Europa is one of Jupiter's four moons, with a diameter of 2,920 kilometers, only about a quarter of the diameter of the Earth, and slightly smaller than the Earth's moon. Scientists speculate that Europa's surface temperature averages about -163°C at the equator and even lower at the poles, only -223°C, so the water on the surface is permanently frozen. But the heat provided by tidal forces may keep the water beneath the ice liquid, and Europa's 60-hour daylight on Europa makes it possible for the cracks in the surface ice to receive plenty of sunlight. Even so, if humans were to conquer Europa one day, it would be difficult to migrate for long.

In addition to Europa, Mars is thought to be another star that may have life forms, as scientists have found that liquid water may still be present deep underground on Mars. Compared to Europa, Mars is closer to Earth, so scientists have been paying close attention to the exploration of the mystery of life on Mars. Future space missions have already made Mars and Europa the final destinations for launching new remotely controlled probes. Mars and Europa, who will be the first to prove to be brothers or strangers to Earth?

NASA announced on the 11th that clay-type minerals have been discovered for the first time on the surface of Europa, the moon of Jupiter, which is the most likely to have life, which means that Europa may have organic matter essential for the formation of life.

NASA said in a statement on the same day that a clay-type mineral called layered silicate was found on Europa's surface, which was most likely brought by a comet or asteroid impact on Europa, and that the comet or asteroid that brought clay-type minerals usually carries organic matter as well.

It is hypothesized that life may exist in the subglacial oceans, and its habitat may be similar to the deep-sea hydrothermal vents on Earth or Lake Vostok in Antarctica, and its life form may be similar to that of some extremophiles on Earth. Although there is no evidence yet, several proposals have been proposed to send space probes to Europa based on the possible presence of liquid water (more on this section).

On December 11, 2013, the National Aeronautics and Space Administration (NASA) announced that a probe had discovered clay-like minerals on Europa, which was covered in ice and snow after its impact with comets and asteroids. Based on the near-infrared images of Europa taken by the Galileo probe in 1998, the NASA research team believes that Europa has a mineral similar to acyl chloride on Europa. Because the central nucleus of an asteroid or comet contains life-forming organisms, NASA researchers say that Europa's snow and ice surface may hide vast oceans, which may be life-threatening over a long period of time.

U.S. and German researchers have published reports that fountains with intermittent eruptions have been found on one of Jupiter's moons, Europa, the best evidence that a huge ocean is hidden beneath Europa's frozen surface. Once there is water, it means that there may be life! For a long time, scientists believed that Europa could have life.

Foreign media said that new research shows that one of Jupiter's moons, Europa, is rich in important minerals, as well as a spectacular water column erupting from the underground ocean, which may be another habitable place in the solar system.

According to a report by the British "Independent" on the 12th, the Hubble telescope confirmed two huge plumed water columns that erupted intermittently on Europa, up to 200 kilometers, and another study found scattered earth-like minerals on the frozen surface of the planet.

The article published in the journal Science says that an analysis of data from the Hubble telescope found that the water column usually erupts at certain specific moments as Europa orbits Jupiter, suggesting that the eruption is caused by periodic huge tidal forces that increase the pressure on the planet's subterranean ocean, causing its liquid to gush out of the ice cracks on the surface, according to the article published in the journal Science.

The report pointed out that of the 63 known moons of Jupiter, Europa is the most important. Astronomers believe that there are oceans under its ice surface and it is due to the heat of the tidal forces that keeps it liquid. Some scientists believe that there may be life in this ocean, and that minerals and tidal heat energy can provide energy for it.

Another study of data collected by NASA's Galileo program revealed that important earth-like minerals found on Europa's surface may have been produced by previous collisions with asteroids or comets.

"We often find important materials for life on comets or primitive asteroids – organic minerals, and the discovery of remnants of collisions with such comets on Europa's surface could open a new chapter in our search for life on the planet," said Jim Shirley of NASA's Jet Propulsion Laboratory. ”

According to reports, many scientists believe that Europa may be the most suitable planet for life in the solar system outside of Earth.

Launched as early as 2023, Europa Clipper will carry nine instruments to the Jupiter system and orbit Europa for more than 3 years to gather important information about the moon's geology, composition, and hidden inner oceans, as well as assess the moon's habitability.