Europa, discovered by Galileo in 1610, Europa, is slightly smaller than the Moon, reaching 3,100 kilometers in diameter, and is the fourth largest moon of Jupiter, the sixth largest moon in the solar system, and the fifteenth largest celestial body in the solar system. Pen & Fun & Pavilion www.biquge.info

Europa has a rarefied atmosphere containing oxygen, which is almost negligible compared to Earth's atmosphere. Unlike oxygen in the Earth's atmosphere, Europa's oxygen is not formed by biological activity. Most likely, it is caused by the impact of charged particles in sunlight on Europa's icy surface, which then splits into hydrogen and oxygen. Eventually, the hydrogen gradually detached, leaving only oxygen.

Europa is composed mainly of silicate rocks with an outer layer of ice + water up to 100 km thick. Europa has a very "smooth" surface, and because of this, it is one of the brightest moons in the solar system. In addition, the low number of impact craters on the planet's surface also indicates that its geological structure is relatively active, and observational data suggest that Europa has an internal layered structure and may have a small metal core.

"Europa's surface is indeed very similar to the ice on Earth's oceans!"

"This is even more indicative of the presence of a large amount of liquid water beneath Europa's ice shell."

"Guess what, it's all here, don't you have a result if you scan it with a detector!"

The spacecraft of scientific exploration has entered Europa's outer orbit, and scientists from Jupiter's space city are discussing it with great interest.

After scanning, it turned out that there was a large amount of liquid water beneath Europa's ice, which was the subglacial ocean world that had been predicted by the scientific community for a long time.

"The average thickness of the ice is 2.6 kilometers."

"The change in the color of Europa's surface may be the result of differences in geological characteristics. For example, that blue-white area may contain relatively pure ice water matter, while this reddish-brown area will contain much less ice water matter......"

The most striking feature of Europa from this close range is the dark brown cross stripes that dot the world's ice. Scientists speculate that these dark brown cross streaks may have been created by a series of volcanic ejections or fountains.

In addition, Europa's surface is dotted with a large number of stunning linear cracks. Scientists believe that these intricate surfaces indicate that there are cracks in the ice on Europa's surface, and some places are refilled after the break, indicating that there is a certain circulation and activity under the ice of Europa, which is very favorable for the birth of life.

......

In the command center of the Earth IEA headquarters, Hara was looking at the giant display screen with a calm demeanor, which was playing video information collected by Europa's spacecraft and scientific action team.

At this time, the distance from Jupiter to Earth is 630 million kilometers, and the signal is delayed for more than 30 minutes.

"Report to the Commander, a landing request from the Europa Science Exploration Spacecraft, please instruct."

A staff member strode over and reported to Yuan Haochen.

"By request!" After Yuan Haochen gave the order, he added, "Let them pay attention to safety, remain cautious, and act independently according to the plan, and there is no need to submit an application to me in non-major situations." ”

"Understood!"

An hour later.

A large silver-gray spaceship slows down as it back-jets its engines and approaches Europa.

Nearly 3 kilometers of solid ice is theoretically enough to safely carry a spacecraft. However, the high-temperature gases ejected from the engine can quickly melt the surface of the ice, so the scientific exploration team has also spent some thought and made some clever design and arrangement in the attitude and technical details of the spacecraft's landing.

The surging heat of the air swept up the sky with ice, splashes, and steam. The spaceship has finally landed successfully and is standing tall on this icy and snowy land.

Europa, like the frozen Saturn that Hara Ha Chen once visited, is a frozen world that is so cold that it is extremely romantic and dusty.

"The atmospheric pressure is negligible, the temperature is -163 degrees Celsius!! You see, the ice water that had just melted was instantly frozen again. ”

"There is very strong radiation, so everyone should pay attention to prepare for protection."

Before leaving the spacecraft, the scientists first analyzed the surrounding environment.

"It's a real place of ice and snow. Every inch of land under our feet is part of the ice sheet!! ”

Everyone left the spaceship and looked around, and the entire planet was a silvery white block of ice, glowing faintly in the cold light.

Because the gravitational acceleration on Europa's surface is only 1.314 m/s2, it will take a little time for scientists to get used to working in such a low-gravity environment.

On the first day, the scientific exploration team was limited to the surface of the ice sheet.

In the brown streaks on the surface of the dry, frozen ice sheet, scientists have found traces of clay minerals.

They also pinpointed several salt lakes under ice floes.

In addition, the scientists involved in the scientific action also observed that some ice plates on Europa's ice were squeezed by neighboring ice plates and finally dived into the sea.

This is evidence that all the chemical components on the surface of the celestial body and inside the ice crust are in the same cyclic chain. In other words, it is possible that the material and chemical components of the surface of the earth from space may eventually enter the underground sea.

These discoveries greatly encouraged the scientists involved in the operation, and all kinds of indications pointed to the possibility of life on Europa.

"Poof!!"

There was no air, no sound, and a fountain 200 kilometers high suddenly erupted silently and without warning in the area called [Chaotic Terrain].

The 200-kilometer-high fountain is spectacular! It's like a majestic water dragon gathering momentum to reach the sky!!

"Quick, it's finally time for the geyser to erupt, let's evacuate the [Chaotic Terrain] first and stay as far away from here as possible."

Everyone set up the fountain collection device, and then quickly finished their work, and left with a big leap.

The fountains on Europa erupt intermittently, each erupting lasts about 7 hours. Since the fountain phenomenon always appears at Europa's farthest point from Jupiter, it disappears at its closest approach. Researchers speculate that it was Jupiter's tidal gravitational influence on Europa that caused cracks in Europa's surface ice at its farthest point, from which fountains erupted, and when Jupiter's periphysis was reached, the cracks gradually closed.

Although, Europa's fountain is somewhat similar to the fountain on Enceladus. However, because Europa's gravity is 12 times greater than that of Enceladus, Europa's fountains, although they erupt high, do not escape into space for the most part like Enceladus's fountains.

Normally, the fountain here falls back to Europa after erupting to an altitude of more than 200 kilometers.

The appearance of the fountain suggests that parts of Europa's frozen surface may be easily "breached" by the ocean inside. Moreover, this intermittent fountain spews material from Europa's surface and deep layers into the air, making it easy for the scientific team to study Europa's inner marine world. (To be continued.) )