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Aliens at Jupiter: under the icy shell of Europe it is possible to meet higher forms of life

1995 brought incredible news to Earth science – one of the 61 satellites of Jupiter, the largest planet in our system, Europe, was covered with a thick layer of ice, ordinary water ice! And where there is water, there is life…

At the same time, the outwardly surface of Europe is noticeably reminiscent of the Antarctic – blocks of ice, split, and then frozen again. The thickness of the ice cover of Europe is estimated at tens of kilometers – from 10 to 150, and under it … a warm ocean, because otherwise it is impossible to explain the appearance of such an ice structure: cracks, hummocks, incredibly huge ice fields.

And, of course, if there is a chance that the ocean flows under the ice, then life is possible in it. NASA recently announced that they are preparing a new mission for Jupiter, with Europe focusing on it. The start of the mission was scheduled for approximately 2025.

But now scientists are trying to predict exactly what life forms will meet in this huge warm ocean – there is twice as much water in Europe than on our planet, and the depth of the ocean is estimated at hundreds of kilometers.

The first assumption is that alien life can be represented by bacteria and microorganisms. But how did they get here?

If one adheres to one of the theories of the spread of life, the theory of panspermia, then life in the Universe “travels” on comets or asteroids. But what is the likelihood that such a “habitable” asteroid will bring life? In order not to bore the calculation, let us immediately say that it is very, very small – 0.00007%. That is, most likely, the life that will develop in Europe will be born here. Or it’s already born.

Now back to the question of what this life form can be? For Mars, the existence of bacteria that will hide under the surface is likely. But Europe or its neighbor, Enceladus, will be able to boast (we always assume, you remember?) microorganisms or even more complex structures, not only based on carbon, but also based on, for example, silicon. And while completely different – as they will develop in completely different conditions and completely different times.

If we accept that life on our planet arose about 4 billion years ago and the first billion were microscopic forms, then, by analogy, life on Europe could also appear billions of years ago, for example, three. Those. microscopic forms have long been passed, and now they can exist on a par with multicellular and even giant organisms (gravity in Europe is about 1% of the earth’s, so the likelihood of developing large life forms is quite high).

There are researchers who go much further in their assumptions – life could already have passed the evolutionary path to intelligent aquatic organisms, somewhat similar to octopuses. So far, this assumption is more on the conscience of science fiction writers. However, discounting it is still not worth it.

Now, speaking of extraterrestrial civilizations, by the way, scientists often still talk about life on the nearest planets of our system than even highly developed civilizations on earth-like exoplanets. And the point here is not only that so far there is no evidence of the existence of life on such planets. It’s just that we still cannot reach them. But to our neighbors in the solar system – we can, or we can in the near future. And, of course, first of all, we, earthlings, will be interested in planets and satellites of planets where the development of intelligent life forms is possible.

So how does humanity meet these life forms? NASA is currently developing a project with the code name Europa Multiple-Flyby Mission. It will be an interplanetary automatic station consisting of a descent probe and a base orbital ship. Such a ship should ensure the operability of the probe for at least 100 days. The total duration of the mission to Europe is 3.5 years. During this time, the zones of Jupiter’s satellite should fly at least 45 times, at different altitudes – from 2700 to 25 km.

The mission will have to check the presence of that very warm ocean under the ice surfaces, determine the composition of the ocean and … identify the possible landing sites for the descent vehicles of the following missions.

The main thing is that during these studies from the oceans of Europe, its inhabitants do not appear, which Earth spaceships may like, as was the case in the film “Europe” …

Based on materials:  https://phys.org

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ESPRESSO spectrograph confirms the existence of an earth-like planet near Proxima Centauri

The surface of Proxima b through the eyes of the artist ESO / M. Kornmesser

The ESPRESSO spectrograph confirmed the existence of the earth-like exoplanet Proxima b in the star closest to the Sun. Additional observations made by the tool made it possible to clarify its mass, as well as register a second signal, which theoretically can be explained by the presence of another planet. Accepted for publication at Astronomy & Astrophysics, the preprint is available at arXiv.org.

In 2016, astronomers reported the discovery of the planet at the red dwarf Proxima Centauri, the closest star to Earth, located about 4.2 light-years from Earth. The celestial body revolves around the star with a period of 11.2 days and is in the habitable zone – this means that the conditions on its surface allow the existence of liquid water. 

The discovery of Proxima b was one of the most important milestones in exoplanetary astronomy in recent years, but the limited accuracy of the available measurements of radial velocity and the complexity of the simulation required confirmation of the existence of an earth-like planet.

An international group of astronomers used the new-generation spectrograph ESPRESSO, which is part of the VLT complex, to measure the radial velocity of a star with an accuracy of 30 centimeters per second. The data obtained were three times more accurate than the data of the HARPS spectrograph, an instrument of the same type, but of the previous generation, with the help of which the discovery was made. Combining ESPRESSO observations with past measurements showed that the mass of Proxima b is not less than 1.17 earth masses, which is less than the previous estimate of 1.27 earth masses.

In addition, scientists recorded an additional signal repeating with a period of 5.5 days, which so far they have not been able to explain. Hypothetically, it can come from the second planet: if the assumption is true, then its minimum mass is less than a third of the earth, and it is located at a distance of 0.03 astronomical units from Proxima Centauri (one astronomical unit is equal to the average distance from the Earth to the Sun).

In the past, researchers suspected the existence of another planet in the system – this time the super-earth, on which the year lasts about five years. It is five and a half times more massive than the Earth and may have rings similar to the rings of Saturn, but this discovery has not yet been confirmed.

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It’s time to worry. Planets switched to retrograde motion

© NASA / Tunc Tezel

In May, Venus, Saturn and Jupiter become retrograde – they change the direction of motion in the celestial sphere. Previously, it was considered a bad omen. In fact, in the solar system there is only one real retrograde – Venus. But the discovery of retrograde exoplanets was a complete surprise.

Copernicus explained everything

Even in ancient times, people noticed that planets moving in the heavens sometimes behave strangely, loop. Most of the year they follow from west to east (if they are farther from the Sun than the Earth) and suddenly turn around, back down. The moment when this happens is called standing.In 1514, Nicolaus Copernicus proved that the Earth is not the center of the universe, but together with other planets revolves around the Sun. 

Each celestial body has its own orbit, and the retrograde movement that is visible to us is the result of their superposition. For example, Mars approaches the Earth every two years as closely as possible and, overtaking it, draws an s-shaped loop in the sky.

© NASA / Tunc Tezel

The path of Mars in the celestial sphere in the period from July 2005 to February 2006. It goes from west to east and at the moment of approaching the Earth makes a loop. For a couple of months his movement seems retrograde to us.

Venus and Uranus versus all

All planets in relation to the Earth for a short time move backward, but this is only an appearance. Real retrogrades do not physically rotate like the rest. In the solar system, it is only Venus. If we were above the north pole of Venus, we would see that it rotates clockwise around its axis. Earth and other planets are against.It is believed that planets form together with a star from one protoplanetary disk. In theory, their orbits should lie in the same plane, and the directions of rotation in the orbit and around the axis should coincide. Why Venus is not like this is not yet clear. 

Although scientists note its strong similarity with the Earth – these planets are even called twins. One of the explanations is that the processes occurring in the bowels and atmosphere have slowed the rotation of Venus so much that it stopped at some point, and then began to spin in another direction.

The distant ice giant Uranus also looks like a retrograde. It lies on its side relative to the plane of its orbit, and pecks down the north pole, which makes Uranus seem to rotate clockwise. But if you put it normally, it will become normal. Scientists believe that billions of years ago, Uranus collided with a large cosmic body and turned over in space. Another hypothesis is that in the past the planet had a massive system of rings that caused resonance, rocked it and deployed.

General rules apply to planetary moons. For example, the Earth rotates counterclockwise, and so does the Moon around the Earth. But one of the 13 moons of Neptune – Triton – is “against the coat.” So, scientists conclude, Triton did not belong to Neptune, was an independent small body, until Neptune captured it from the Kuiper belt. By the way, Pluto, similar in composition to Triton, is also retrograde. In part, this contributed to its transfer to the category of dwarf planets.

© Illustration by RIA Novosti. NASA / JPLRetrograde motion of Triton. This is the only major satellite in the solar system that moves in orbit against the course of its planet.

Anomalies of hot jupiters

This is what our system is completely devoid of – planets that would move in orbits against the rotation of the Sun. For a long time, astronomers believed that this should be everywhere. But in 2009, they discovered the first exoplanet with a retrograde orbit at the star WASP-17 in the constellation Scorpio.WASP-17 b is the largest and least dense exoplanet known. Such gas giants are called hot jupiters.

Its retrograde intrigues scientists. Smadar Naoz from the Center for Interdisciplinary Research in Astrophysics at Northwestern University ( USA ) proposed a possible mechanism: the mutual influence of giant planets during migration closer to a star or a brown dwarf. But its implementation requires the coincidence of too many conditions, and this is unlikely. Nevertheless, the astrophysicist put forward a bold hypothesis that such retrograde jupiters are not uncommon – a quarter among those observed. However, the existence of the hot Jupiters themselves is still waiting for its explanation.

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A space object that changes the concept of the Universe is discovered: An unthinkable ancient galaxy

Photo: NRAO / AUI / NSF / S. Dagnello

Scientists at the Institute for Astronomy of the Max Planck Society in the UK announced the discovery of the oldest massive galaxy DLA0817g, which arose just 1.5 billion years after the Big Bang. It has a disk, which can change astronomers’ ideas about the mechanisms of galaxy formation. An article by astronomers is published in the journal Nature.

Researchers discovered the galaxy using the ALMA (Atacama Large Millimeter Array) radio telescope complex. This ancient object was named Wolf Disc – in honor of the astronomer Arthur Wolf. It has become the farthest spinning-disk galaxy of all detected so far, and its cosmological redshift is 4.26. 

The light from it flew 12.2 billion years, but due to the expansion of the Universe, the galaxy is currently at a distance of 24.4 billion light years. The rotation occurs at a speed of 272 kilometers per second, which is comparable to the rotation speed of the Milky Way.

According to modern models, massive galaxies are formed from the mergers of smaller mass galaxies and clusters of hot gas. These collisions prevent the formation of disks characteristic of the Universe of this age. 

Therefore, the existence of the Wolf Disc will force astronomers to reconsider the mechanisms of the appearance of such space objects. DLA0817g probably accumulated cold gas, but the question of how he managed to maintain a stable disk with such a large mass remains open.

Scientists also found that the star formation rate in the Wolf Disk is ten times higher than the star formation rate in the Milky Way. According to astronomers, he was one of the most productive galaxies in the early Universe.

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