All the secrets of the solar system

The secrets of our star system are divided into well-known, covered in the media, for example, questions about life on Mars, Europa, Enceladus or Titan, structures and phenomena inside large planets, secrets of the far edges of the System, and those that are less publicized. We want to get to all the secrets, so let's focus on the lesser ones this time.

Let's start from the "beginning" of the Pact, i.e. from Sun. Why, for example, the south pole of our star is colder than its north pole by about 80 thousand. Kelvin? This effect, noticed long ago, in the middle of the XNUMXth century, does not seem to depend onmagnetic polarization of the sun. Perhaps the internal structure of the Sun in the polar regions is somehow different. But how?

Today we know that they are responsible for the dynamics of the Sun. electromagnetic phenomena. Sam may not be surprising. After all, it was built with plasma, charged particle gas. However, we do not know exactly which region Sun is created a magnetic fieldor somewhere deep inside her. Recently, new measurements have shown that the Sun's magnetic field is ten times stronger than previously thought, so this puzzle is becoming more and more intriguing.

The sun has an 11-year activity cycle. During the peak period (maximum) of this cycle, the Sun is brighter and more flares and sunspots. Its magnetic field lines create an increasingly complex structure as it approaches solar maximum (1). When a series of outbreaks known as coronal mass ejectionsthe field is flattened. During solar minimum, the lines of force begin to go straight from pole to pole, just like on Earth. But then, due to the rotation of the star, they wrap around him. Eventually, these stretching and stretching field lines "tear" like a rubber band pulled too tight, causing the field to explode and silence the field back to its original state. We have no idea what this has to do with what's going on under the surface of the Sun. Perhaps they are caused by the action of forces, convection between the layers inside the sun?

1. Lines of the magnetic field of the Sun

next solar puzzle - why the solar atmosphere is hotter than the surface of the Sun, i.e. photosphere? So hot that it can be compared with the temperature in sun core. The solar photosphere has a temperature of about 6000 kelvins, and the plasma just a few thousand kilometers above it is over a million. It is currently believed that the coronal heating mechanism may be a combination of magnetic effects in solar atmosphere. There are two main possible explanations coronal heating: nanoflari i wave heating. Perhaps the answers will come from research using the Parker probe, one of the main tasks of which is to enter the solar corona and analyze it.

With all its dynamics, however, judging by the data, at least for the last time. Astronomers from the Max Planck Institute, in collaboration with the Australian University of New South Wales and other centers, are conducting research to determine exactly if this is actually the case. The researchers use the data to filter out sun-like stars from the 150 XNUMX catalog. main sequence stars. Changes in the brightness of these stars, which, like our Sun, are at the center of their lives, have been measured. Our Sun rotates once every 24,5 days.so the researchers focused on stars with a rotation period of 20 to 30 days. The list has been further narrowed down by filtering out surface temperatures, ages, and the proportion of elements best suited to the Sun. The data obtained in this way testified that our star was indeed quieter than the rest of its contemporaries. solar radiation it fluctuates by only 0,07 percent. between the active and inactive phases, the fluctuations for other stars were usually five times larger.

Some have suggested that this does not necessarily mean that our star is generally quieter, but that it is, for example, going through a less active phase lasting several thousand years. NASA estimates that we are facing a "great minimum" that happens every few centuries. The last time this happened was between 1672 and 1699, when only fifty sunspots were recorded, compared to 40 50 - 30 thousand sunspots on average over XNUMX years. This eerily quiet period became known as the Maunder Low three centuries ago.

Mercury is full of surprises

Until recently, scientists considered it completely uninteresting. However, missions to the planet showed that, despite the increase in surface temperature to 450 ° C, it, apparently, Mercury there is water ice. This planet also seems to have a lot the inner core is too large for its size and a little bit amazing chemical composition. The secrets of Mercury can be solved by the European-Japanese mission BepiColombo, which will enter the orbit of a small planet in 2025.

Data from NASA MESSENGER spacecraftwhich orbited Mercury between 2011 and 2015 showed that material on Mercury's surface had too much volatile potassium compared to more a stable radioactive track. Therefore, scientists began to investigate the possibility that mercury he could stand further from the sun, more or less so, and was thrown closer to the star as a result of a collision with another large body. A powerful blow may also explain why mercury it has such a large core and a relatively thin outer mantle. Mercury core, with a diameter of about 4000 km, lies inside a planet with a diameter of less than 5000 km, which is more than 55 percent. its volume. For comparison, the diameter of the Earth is about 12 km, while the diameter of its core is only 700 km. Some believe that Merukri was devoid of great clashes in the past. There are even claims that Mercury could be a mysterious bodywhich probably struck the Earth about 4,5 billion years ago.

American probe, in addition to the amazing water ice in such a place, in Mercury craters, she also noticed small dents on what was there Crater Gardener (2) The mission discovered strange geological features unknown to other planets. These depressions appear to be caused by the evaporation of matter from within Mercury. it looks like a Outer layer of Mercury some volatile substance is released, which is sublimated into the surrounding space, leaving behind these strange formations. It was recently revealed that the scythe following Mercury is made of a sublimating material (perhaps not the same). Because BepiColombo will start its research in ten years. after the end of the MESSENGER mission, scientists hope to find evidence that these holes are changing: they increase, then decrease. This would mean that Mercury is still an active, living planet, and not a dead world like the Moon.

2. Mysterious structures in the crater Kertes on Mercury

Venus is battered, but what?

Why Venus so different from Earth? It has been described as the Earth's twin. It is more or less similar in size and lies in the so-called residential area around the sunwhere there is liquid water. But it turns out, besides the size, there are not so many similarities. It is a planet of endless storms raging at 300 kilometers per hour, and the greenhouse effect gives it an average hellish temperature of 462 ° Celsius. It's hot enough to melt lead. Why such other conditions than on Earth? What caused this powerful greenhouse effect?

Atmosphere of Venus up to w 95 percent. carbon dioxide, the same gas that is the main cause of climate change on Earth. When you think that atmosphere on Earth is only 0,04 percent. WHAT KIND₂you can understand why it is the way it is. Why is there so much of this gas on Venus? Scientists believe that Venus used to be very similar to Earth, with liquid water and less CO.₂. But at some point it got warm enough for the water to evaporate, and since water vapor is also a potent greenhouse gas, it only exacerbated the heating. Eventually it got hot enough for the carbon trapped in the rocks to be released, eventually filling the atmosphere with carbon dioxide.₂. However, something must have nudged the first domino in successive waves of heating. Was it some kind of disaster?

Geological and geophysical research on Venus began in earnest when it entered its orbit in 1990. Magellan probe and continued to collect data until 1994. Magellan has mapped 98 percent of the planet's surface and transmitted thousands of breathtaking images of Venus. For the first time, people get a good look at what Venus really looks like. Most surprising was the relative lack of craters compared to others such as the Moon, Mars, and Mercury. Astronomers wondered what could have made the surface of Venus look so young.

As scientists looked more closely at the array of data returned by Magellan, it became increasingly clear that this planet's surface must somehow be quickly "replaced", if not "tipped over". This catastrophic event should have happened 750 million years ago, so very recently in geological categories. Don Tercott from Cornell University in 1993 suggested that the Venusian crust eventually became so dense that it trapped the planet's heat inside, eventually flooding the surface with molten lava. Turcott described the process as cyclical, suggesting that an event several hundred million years ago could be just one in a series. Others have suggested that volcanism is responsible for the "replacement" of the surface and that there is no need to look for an explanation in space disasters.

They are different mysteries of Venus. Most planets rotate counterclockwise when viewed from above. Solar system (that is, from the North Pole of the Earth). However, Venus does just the opposite, leading to the theory that a massive collision must have occurred in the area in the distant past.

Is it raining diamonds on Uranus?

, the possibility of life, the secrets of the asteroid belt, and the mysteries of Jupiter with its enchanting huge moons are among the "well-known mysteries" we mention at the beginning. The fact that the media writes a lot about them does not mean, of course, that we know the answers. It simply means that we know the questions well. The latest in this series is the question of what causes Jupiter's moon, Europa, to shine from the side not illuminated by the Sun (3). Scientists are betting on influence Jupiter's magnetic field.

3. Artistic rendering of the moonlight of Jupiter, Europe

Much has been written about Fr. Saturn system. In this case, however, it's mostly about its moons and not about the planet itself. Everyone is enchanted unusual atmosphere of titan, the promising liquid inland ocean of Enceladus, the enigmatic double color of Iapetus. There are so many mysteries that less attention is paid to the gas giant itself. Meanwhile, it has much more secrets than just the mechanism of formation of hexagonal cyclones at its poles (4).

4. Hexagonal cyclone at the pole of Saturn.

Scientists note in vibration of the planet's ringscaused by vibrations within it, many disharmony and irregularities. From this they conclude that a huge amount of matter must occur under a smooth (compared to Jupiter) surface. Jupiter is being studied at close range by the Juno spacecraft. And Saturn? He did not live to see such an exploratory mission, and it is not known if he will wait for one in the foreseeable future.

However, despite their secrets, Saturn it seems to be quite a close and tame planet compared to the closest planet to the sun, Uranus, a real weirdo among the planets. All planets in the solar system revolve around the sun in the same direction and in the same plane, according to astronomers, is a trace of the process of creating a whole from a rotating disk of gas and dust. All planets, except Uranus, have an axis of rotation directed approximately "up", that is, perpendicular to the plane of the ecliptic. On the other hand, Uranus seemed to lie on this plane. For very long periods (42 years), its north or south pole points directly at the Sun.

Unusual axis of rotation of Uranus this is just one of the attractions that its space society offers. Not so long ago, the remarkable properties of its nearly thirty known satellites were discovered and ring system received a new explanation from Japanese astronomers led by Professor Shigeru Ida from the Tokyo Institute of Technology. Their research shows that at the beginning of our history The solar system Uranus collided with a large icy planetthat forever turned away the young planet. According to a study by Prof. Ida and his colleagues, giant collisions with distant, cold and icy planets will be completely different from collisions with rocky planets. Because the temperature at which water ice forms is low, much of Uranus's shock wave debris and its icy impactor may have evaporated during the collision. However, the object has previously been able to tilt the planet's axis, giving it a fast rotation period (Uranus' day is now around 17 hours), and the tiny debris from the collision stayed in a gaseous state longer. The remnants will eventually form small moons. The ratio of the mass of Uranus to the mass of its satellites is a hundred times greater than the ratio of the mass of the Earth to its satellite.

For a long time Uran he was not considered particularly active. This was until 2014, when astronomers recorded clusters of giant methane storms that swept across the planet. Previously it was thought that storms on other planets are powered by the energy of the sun. But solar power is not strong enough on a planet as far away as Uranus. As far as we know, there is no other source of energy that would fuel such strong storms. Scientists believe that Uranus' storms start in its lower atmosphere, as opposed to storms caused by the sun above. Otherwise, however, the cause and mechanism of these storms remain a mystery. Uranus atmosphere can be much more dynamic than it appears from the outside, generating heat that fuels these storms. And it can be much warmer there than we imagine.

Like Jupiter and Saturn The atmosphere of Uranus is rich in hydrogen and helium.but unlike its larger cousins, uranium also contains a lot of methane, ammonia, water, and hydrogen sulfide. Methane gas absorbs light in the red end of the spectrum., giving Uranus a bluish-green tint. Deep below the atmosphere lies the answer to another great mystery of Uranus - its uncontrollability. a magnetic field it is tilted 60 degrees from the axis of rotation, being considerably stronger at one pole than at the other. Some astronomers believe that the warped field may be the result of huge ionic liquids hidden under greenish clouds filled with water, ammonia, and even droplets of diamond.

He's in his orbit 27 known moons and 13 known rings. They are all as strange as their planet. Rings of Uranus they are not made of bright ice, as around Saturn, but of rock debris and dust, so they are darker and harder to see. Rings of Saturn dissipate, astronomers suspect, in a few million years the rings around Uranus will remain much longer. There are also moons. Among them, perhaps the most "plowed object of the solar system", Miranda (5). What happened to this mutilated body, we also have no idea. When describing the movement of the moons of Uranus, scientists use words such as "random" and "unstable". The moons are constantly pushing and pulling each other under the influence of gravity, making their long orbits unpredictable, and some of them are expected to crash into each other over millions of years. It is believed that at least one of Uranus' rings was formed as a result of such a collision. The unpredictability of this system is one of the problems of a hypothetical mission to orbit this planet.

The moon that ousted other moons

We seem to know more about what is happening on Neptune than on Uranus. We know about record hurricanes reaching 2000 km/h and we can see dark spots of cyclones on its blue surface. Also, just a little more. We wonder why blue planet gives off more heat than it receives. Strange considering Neptune is so far from the Sun. NASA estimates that the temperature difference between the heat source and the upper clouds is 160° Celsius.

No less mysterious around this planet. Scientists wonder what happened to neptune's moons. We know two main ways that satellites acquire planets - either satellites are formed as a result of a giant impact, or they are left over from formation of the solar system, formed from the orbital shield around the world's gas giant. land i March they probably got their moons from huge impacts. Around gas giants, most moons initially form from an orbital disk, with all large moons rotating in the same plane and ring system after their rotation. Jupiter, Saturn and Uranus fit this picture, but Neptune does not. There's one big moon here Traitonwhich is currently the seventh largest moon in the solar system (6). Looks like it's a captured object passes Kuiperwhich by the way destroyed almost the entire Neptune system.

6. Comparison of the sizes of the largest satellites and dwarf planets of the solar system.

Orbit Trytona deviates from convention. All other large satellites known to us - the Earth's Moon, as well as all the large massive satellites of Jupiter, Saturn and Uranus - rotate approximately in the same plane as the planet on which they are located. Moreover, they all rotate in the same direction as the planets: counterclockwise if we look "down" from the north pole of the Sun. Orbit Trytona has an inclination of 157° compared to the moons, which rotate with Neptune's rotation. It circulates in a so-called retrograde: Neptune rotates clockwise, while Neptune and all other planets (as well as all satellites inside Triton) rotate in the opposite direction (7). In addition, Triton is not even in the same plane or next to it. in the orbits of Neptune. It is tilted about 23° to the plane in which Neptune rotates on its own axis, except that it rotates in the wrong direction. It's a big red flag that tells us that Triton didn't come from the same planetary disk that formed the inner moons (or moons of other gas giants).

7. Triton's orbital inclination around Neptune.

At a density of about 2,06 grams per cubic centimeter, Triton's density is anomalously high. There is covered with different ice cream: Frozen nitrogen covering layers of frozen carbon dioxide (dry ice) and a mantle of water ice, making it similar in composition to the surface of Pluto. However, it must have a denser rock-metal core, which gives it a much greater density than Pluto. The only object known to us comparable to Triton is Eris, the most massive Kuiper belt object, at 27 percent. more massive than Pluto.

There is only 14 known moons of Neptune. This is the smallest number among the gas giants in Solar system. Perhaps, as in the case of Uranus, a large number of smaller satellites revolve around Neptune. However, there are no larger satellites there. Triton is relatively close to Neptune, with an average orbital distance of only 355 km, or about 000 percent. closer to Neptune than the Moon is to Earth. The next moon, Nereid, is 10 million kilometers away from the planet, Galimede is 5,5 million kilometers away. These are very long distances. By mass, if you sum up all the satellites of Neptune, Triton is 16,6%. the mass of everything that revolves around Neptune. There is a strong suspicion that after the invasion of Neptune's orbit, he under the influence of gravity threw other objects into Kuiper's Pass.

This is interesting in itself. The only photographs of Triton's surface that we have were taken Sondi Voyager 2, show about fifty dark bands that are thought to be cryovolcanoes (8). If they are real, then this would be one of the four worlds in the solar system (Earth, Venus, Io and Triton) known to have volcanic activity on the surface. The color of Triton also does not match with other moons of Neptune, Uranus, Saturn or Jupiter. Instead, it pairs perfectly with objects like Pluto and Eris, large Kuiper belt objects. So Neptune intercepted him from there - so they say today.

Beyond the Kuiper Cliff and Beyond

Za orbit of Neptune Hundreds of new, smaller objects of this type were discovered in early 2020. dwarf planets. Astronomers from the Dark Energy Survey (DES) reported the discovery of 316 such bodies outside the orbit of Neptune. Of these, 139 were completely unknown prior to this new study, and 245 were seen in earlier DES sightings. An analysis of this study was published in a series of supplements to an astrophysical journal.

Neptun revolves around the Sun at a distance of about 30 AU. (I, Earth-Sun distance). Beyond Neptune lies Plike Kuyper - a band of frozen rocky objects (including Pluto), comets and millions of small, rocky and metallic bodies, having in total from several tens to several hundred times more mass than not an asteroid. We currently know about three thousand objects called Trans-Neptunian Objects (TNOs) in the Solar System, but the total number is estimated to be closer to 100 9 (XNUMX).

9. Size comparison of known trans-Neptunian objects

Thanks to the approaching in 2015 New Horizons probes head to Plutowell, we know more about this degraded object than about Uranus and Neptune. Of course, take a closer look and study this dwarf planet gave rise to many new mysteries and questions, about amazingly vibrant geology, about a strange atmosphere, about methane glaciers and dozens of other phenomena that surprised us in this distant world. However, the mysteries of Pluto are among the "better known" in the sense that we have already mentioned twice. There are many less popular secrets in the area where Pluto plays.

For example, comets are believed to have originated and evolved in the far reaches of space. in the Kuiper belt (beyond the orbit of Pluto) or beyond, in a mysterious region called Oort Cloud, these bodies from time to time solar heat causes the ice to evaporate. Many comets hit the Sun directly, but others are more fortunate to make a short cycle of rotation (if they were from the Kuiper belt) or a long one (if they were from the Ortho cloud) around the Sun's orbit.

In 2004, something strange was found in the dust collected during NASA's Stardust mission to Earth. Comet Wild-2. Grains of dust from this frozen body indicated that it was formed at a high temperature. Wild-2 is thought to have originated and evolved in the Kuiper Belt, so how could these tiny specks form in an environment over 1000 Kelvin? The samples collected from Wild-2 could only have originated in the central region of the accretion disk, near the young Sun, and something carried them to distant regions. Solar system to the Kuiper belt. Just now?

And since we wandered there, maybe we should ask why Not Kuiper did it end so abruptly? The Kuiper belt is a huge region of the solar system that forms a ring around the sun just beyond the orbit of Neptune. The population of Kuiper Belt Objects (KBOs) is suddenly declining within 50 AU. from the sun. This is rather strange, since theoretical models predict an increase in the number of objects in this place. The fall is so dramatic that it has been dubbed "Kuiper Cliff".

There are several theories about this. It is assumed that there is no real "cliff" and that there are many Kuiper belt objects orbiting around 50 AU, but for some reason they are tiny and unobservable. Another, more controversial concept is that the CMOs behind the "cliff" were swept away by a planetary body. Many astronomers oppose this hypothesis, citing the lack of observational evidence that something huge is orbiting the Kuiper belt.

This fits all the "Planet X" or Nibiru hypotheses. But this may be another object, since the resonant studies of recent years Konstantin Batygin i Mike Brown they see the influence of the “ninth planet” in completely different phenomena, v eccentric orbits objects called Extreme Trans-Neptunian Objects (eTNOs). The hypothetical planet responsible for the "Kuiper cliff" would be no larger than the Earth, and "the ninth planet", according to the astronomers mentioned, would be closer to Neptune, much larger. Maybe they are both there and hiding in the dark?

Why don't we see the hypothetical Planet X despite having such a significant mass? Recently, a new suggestion has emerged that may explain this. Namely, we do not see it, because it is not a planet at all, but, perhaps, the original black hole left after Big Bang, but intercepted sun gravity. Although more massive than the Earth, it would be about 5 centimeters in diameter. This hypothesis, which is Ed Witten, a physicist at Princeton University, has emerged in recent months. The scientist proposes to test his hypothesis by sending to a place where we suspect the existence of a black hole, a swarm of laser-powered nanosatellites, similar to those developed in the Breakthrough Starshot project, whose goal is an interstellar flight to Alpha Centauri.

The last component of the solar system should be the Oort Cloud. Only not everyone knows that it even exists. It is a hypothetical spherical cloud of dust, small debris, and asteroids orbiting the Sun at a distance of 300 to 100 astronomical units, mostly composed of ice and solidified gases such as ammonia and methane. It extends for about a quarter of the distance to Proxima Centauri. The outer limits of the Oort Cloud define the limit of the gravitational influence of the solar system. The Oort cloud is a remnant from the formation of the solar system. It consists of objects ejected from the System by the force of gravity of gas giants in the early period of its formation. Although there are still no confirmed direct observations of the Oort Cloud, its existence must be proven by long-period comets and many objects from the centaur group. The outer Oort Cloud, weakly bound by gravity to the solar system, would be easily disturbed by gravity under the influence of nearby stars and.

Spirits of the solar system

Diving into the mysteries of our System, we have noticed many objects that once supposedly existed, revolved around the Sun and sometimes had a very dramatic impact on events at an early stage in the formation of our cosmic region. These are peculiar "ghosts" of the solar system. It is worth looking at things that are said to have once been here, but now either no longer exist or we cannot see them (10).

10. Hypothetical missing or invisible objects of the solar system

Astronomers they once interpreted the singularity Orbit of Mercury as a sign of the planet hiding in the rays of the sun, the so-called. Vulcan. Einstein's theory of gravity explained the orbital anomalies of a small planet without resorting to an extra planet, but there may still be asteroids ("volcanoes") in this zone that we have yet to see.

Must be added to the list of missing objects the planet Theya (or Orpheus), a hypothetical ancient planet in the early solar system that, according to growing theories, collided with early earth About 4,5 billion years ago, some of the debris created in this way was concentrated under the influence of gravity in the orbit of our planet, forming the Moon. If that had happened, we would probably never have seen Thea, but in a sense, the Earth-Moon system would have been her children.

Following the trail of mysterious objects, we stumble Planet V, the hypothetical fifth planet of the solar system, which should once have orbited the Sun between Mars and the asteroid belt. Its existence was suggested by scientists working at NASA. John Chambers i Jack Lissauer as a possible explanation for the great bombardments that took place in the Hadean era at the beginning of our planet. According to the hypothesis, by the time of the formation of planets c Solar system five inner rock planets formed. The fifth planet was in a small eccentric orbit with a semi-major axis of 1,8-1,9 AU. This orbit was destabilized by disturbances from other planets, the planet entered an eccentric orbit crossing the inner asteroid belt. Scattered asteroids ended up in paths crossing the orbit of Mars, resonant orbits, as well as intersecting earth orbit, temporarily increasing the frequency of impacts on the Earth and Moon. Finally, the planet entered a resonant orbit of half the magnitude of 2,1 A and fell into the Sun.

To explain the events and phenomena of the early period of the existence of the solar system, a solution was proposed, in particular, called the “jump theory of Jupiter” (). It is assumed that Jupiter orbit then it changed very quickly due to interaction with Uranus and Neptune. In order for the simulation of events to lead to the current state, it is necessary to assume that in the solar system between Saturn and Uranus in the past there was a planet with a mass similar to Neptune. As a result of Jupiter's "leap" into the orbit known to us today, the fifth gas giant was thrown out of the planetary system known today. What happened to this planet next? This probably caused a disturbance in the emerging Kuiper belt, throwing many small objects into the solar system. Some of them were captured as moons, others hit the surface rocky planets. Probably, it was then that most of the craters on the moon were formed. What about the exiled planet? Hmm, this fits the description of Planet X in a strange way, but until we make observations, this is just a guess.

The list there is still quiet, a hypothetical planet orbiting the Oort Cloud, the existence of which was proposed based on the analysis of the trajectories of long-period comets. It is named after Tyche, the Greek goddess of luck and fortune, the kind sister of Nemesis. An object of this type could not but should have been visible in infrared images taken by the WISE space telescope. Analyzes of his observations, published in 2014, suggest that such a body does not exist, but Tyche has not yet been completely removed.

Such a catalog is not complete without Nemesis, a small star, possibly a brown dwarf, that accompanied the sun in the distant past, forming a binary system from the sun. There are many theories about this. Stephen Staller from the University of California at Berkeley presented calculations in 2017 showing that most stars form in pairs. Most assume that the longtime satellite of the Sun has long said goodbye to it. There are other ideas, namely that it approaches the Sun over a very long period, such as 27 million years, and cannot be distinguished due to the fact that it is a faintly luminous brown dwarf and relatively small in size. The latter option does not sound very good, since the approach of such a large object it may threaten the stability of our System.

It seems that at least some of these ghost stories may be true because they explain what we are seeing right now. Most of the secrets we write about above are rooted in something that happened a long time ago. I think a lot has happened because there are countless secrets.