New discoveries hint at the presence of an ocean and geysers on the moon Europa that orbits the planet Jupiter. It seems that the two essential conditions for the formation of life are met there, will we find for the first time extraterrestrial life precisely on Europa's moon?
The name Europa indicates not only a continent on Earth, but also the name of one of the moons that revolves around the planet Jupiter (Earth is the third planet from the Sun, Jupiter is the fifth planet from the Sun and the largest of them all). Unlike the Earth, the planet Jupiter has dozens of moons, but the moon Europa is among the most interesting moons, not only of Jupiter but in the entire solar system. The reason for this is that there is a chance to find the first life forms outside the Earth precisely there, on the moon Europa.
It is very strange to think that there will be life on the moon and not on the planet. We are used to thinking, because of the Earth, that life can only develop on large planets and not on the small moons that orbit them, but the moon Europa (and several other moons in the solar system) challenge this notion. Although the moon Europa is small, it is probably complex enough to support life as we know it. From research on Earth we know that life can exist in very extreme and harsh environments such as craters of volcanoes or acidic and hot lakes. It seems that there are two essential conditions for life as we know it to arise, liquid water (or another liquid) and an energy source. Algae and plants, for example, use sunlight as a source of energy, we discovered heat-resistant bacteria that produce energy from the heat of the water in hot lakes (around one hundred degrees Celsius), and other bacteria produce energy from radioactive decays in rocks in the depths of the earth. They have no sunlight at all but nuclear fissions in rocks and a little moisture.
After these discoveries it is possible to start and check where there are similar conditions outside the earth? Where can you find liquid water and an energy source in space?
In recent years, astronomers have discovered more and more planets orbiting distant suns. Some of these planets are similar in size to Earth and are at a suitable distance from the Sun for liquid water to form. In addition, they also revolve around suns similar to our sun. If indeed there is liquid water on these planets, we have met the two main requirements of life, water and an energy source (sunlight). These are Earth-like planets and as time goes by we discover more and more such planets. It is estimated that there are 11 billion such planets in our galaxy alone, the Milky Way galaxy.
But these planets revolve around very distant suns. The closest Earth-like planet we discovered is 4.5 light years away (45,000,000,000,000 km!). We still can't check if there really is liquid water or life forms there. The big surprise was when it turned out that there could be places in our solar system, right under our nose, where there is liquid water and a source of energy. The most promising place to find these conditions is on Jupiter's moon Europa. Like most celestial bodies far from the Sun, Europa's moon also has a large ice layer. Because of Europa's close proximity to the planet Jupiter, a strange process occurs there, the strong gravitational force of Jupiter pulls more on the side of the moon that is close to the planet and pulls less on the side of the moon that is far from the planet. It so happens that while the moon rotates around its axis, each time a different side of it is more attracted to Jupiter. Because of this phenomenon, the moon goes through slight contractions and expansions and these cause the core in the center of the moon to be active. The core contracts and expands and therefore releases heat energy. The heat in turn melts the inner layers of ice surrounding the moon's core.
We have reached an interesting situation where a simple and small moon hides volcanic activity inside it. If this theory is correct, the result is that beneath the ice layers that we see on Europa's moon, there is a huge ocean of liquid water that was melted by the moon's hot core. Thus, although there is no light in this ice-covered ocean, the two essential conditions for the formation of life can be realized. Both the presence of liquid water and a source of energy (the heat emitted from the moon's core). It is likely that even if life did develop in the ocean of Europa's moon, it would be simple life forms such as bacteria and not large animals that require a very large amount of energy. But even so, this will be the first time that we have found any life outside of Earth. Now the question is, does this process actually occur on Europa's moon and if so, did life forms develop in this subglacial ocean?
There has been indirect evidence of an ocean beneath the ice sheets on Europa's moon for at least ten years. At the end of September 2016, NASA, the American space agency, announced another confirmation of the existence of the ocean. To date, scientists have seen that there are grooves in the ice layers of Europa's moon and that these grooves change over time. The explanation was that because the ice floats on the surface of the ocean of water, the ice layers move and thus the shapes of the grooves that we see on the surface of Europa's moon change. Now NASA has announced that they have apparently found evidence of intense water eruptions on the surface of Europa's moon. A kind of geysers that, among other things, throw liquid water into space. If this discovery turns out to be correct we have received further confirmation that there is an ocean of liquid water on Europa's moon and that there is tectonic activity there (which creates these water eruptions). With the help of the Hubble Space Telescope, they were able to take a close-up image of the surface of Europa's moon using ultraviolet radiation. In three of these ten images they found structures that protrude beyond the face of the moon (reminiscent of the shape of an elongated finger). After further tests they came to the conclusion that it is most likely water eruptions splashed from Europa's moon.
Processing of one of the images taken with the Hubble Space Telescope in ultraviolet radiation. Note the light blue structures that protrude from the surface of Europa's moon into space (at the bottom of the moon on the left side, 7 o'clock). Further tests revealed that these were most likely water eruptions from the surface of the moon.
This is how science works, little by little we test our theories and progress step by step to solving the riddles. There is accumulating indirect evidence that there is indeed a vast ocean beneath the icy layers of Europa's moon. Now probes need to be sent to Europa's moon. The probes will check these water eruptions and analyze them. Perhaps already at this stage we can discover evidence of simple life forms in the water splashing out from the subterranean ocean. The ultimate goal is to send probes that will dig into the ice layers to find the ocean of water that is hiding there. One of the problems is that we still have no idea how thick these ice layers are and how much work the probes will have to put in to dig and reach the ocean. In the future, after further discoveries, we will be able to evaluate this and determine where it is worthwhile to land the probes and dig. Then we will be able to glimpse for the first time an alien and different world and check if there is life there. When will all this happen? It's hard to know, I understand that there are plans for such a mission in the next decade. Perhaps now that these geysers have been found, plans to send probes to Europa's moon will kick into high gear.
More of the topic in Hayadan:
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The moon Europa moves in an elliptical orbit around Jupiter, not a circular one. As a result, the gravitational force exerted by Jupiter on the moon changes during the orbit. The material in different places on the moon feels the force of gravity differently, and the moon warps. In the far part of the orbit, the moon is more like a football (spherical), and when it is close its shape is more like that of an American football ball (rotating ellipsoid) [of course this is a wild exaggeration, the distortion is very small]. The warp transfers energy to the moon which heats it.
Perhaps the Hebrew Language Academy will already work to invent a new name for "planet" so that it will not be necessary to use the name "Planeta"? The names "planet" and "planet Shabbat" are no longer convenient to use. In the meantime - "star" and "planet" is a reasonable interim solution.
Life on Earth is indeed found in very extreme conditions, but it was created in optimal conditions of the warm and pleasant and ideal soup for the formation of life that has existed on Earth for millions of years.
They adapted to the extreme conditions slowly over millions of years thereafter.
But the question is whether there is any chance for life to be created in advance under such extreme conditions as there are in Europe.
The chances of life forming in the conditions of the early Earth in a random way were so low that it is a wonder at all that they were formed in a relatively short time.
Therefore, if they find life in Europe, it will be the proof that God created life in a spontaneous creation and that life is not created randomly.
Roger is right. Europa orbits Jupiter once every 3.5 days, and this is also the time it takes to rotate around its axis (Wikipedia). That is: it is gravitationally locked in front of Jupiter.
So where is the energy?
There is one possibility left that I can think of: radioactive activity in its core, similar to the Earth.
There is also the possibility of weak gravitational friction against the Sun.
"So it happens that while the moon rotates around its axis, each time a different side of it is more attracted to Jupiter" to the best of my knowledge Europa, like most of the moons, is gravitationally locked and points the same side to Jupiter.