News inside out
One of the aspects of the life of the popularizer is the explanation and commenting of the news. Sometimes the original news looks at least strange. And at the same time it often turns out that there are really interesting stories behind the garbage of distortions. Recently, I was asked to comment on the news package, united by a common theme “space objects inside out”. Not all of them turned out to be really turned out, but the initial scientific news, in my opinion, is really curious.
Hollow Earth Globe
News : The unusual "spotted" character of Mercury in terms of its chemical composition found a simple explanation - it turned out that the planet was actually turned inside out, as the rocks from the boundary between the mantle and the core were on its surface, said planetologists at a conference of geophysicists in Yokohama.
Understanding: With a modern search, finding a source of news is usually quick and easy. Typing in English something like "Mercury inside out Yokohama" we find a good publication retelling the real-life performance of NASA scientists in Yokohama.
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Northern Volcanic Plains of Mercury, photo by NASA / JHUAPL / Carnegie Institution of Washington with enhanced colors
The interplanetary station MESSENGER discovered the “problem” of Mercury - regions with great geological diversity were difficult to explain without drawing on the hypothesis of melting of a heterogeneous mantle. An example of such a region is the Northern Volcanic Plains (pictured above). And a group of scientists of the Space Center. Johnson NASA conducted a series of experiments that emulate the conditions of the young Mercury. They took a mixture similar in composition to enstatite chondrites and subjected to pressures and temperatures that were supposed to be on the border of the core and mantle of the young Mercury. Temperatures are not called, and the pressure reached 50 thousand atmospheres. And it turned out that the same chemical composition at different temperatures and pressures gave different rocks, as was discovered on Mercury. Older regions were formed deeper than the boundary between the nucleus and the cortex, and younger regions — at a lesser depth. And how they came to the surface explains the hypothesis of a collision between Mercury and the planetesimal (or Venus), as a result of which Mercury lost most of the crust and upper layer of the mantle.
News : An ancient collision turned the Earth inside out. A cosmic "pebble" the size of a mountain struck our planet about 1.8 billion years ago. In this part of the crust was simply stripped off, like a scalp. In essence, it was turned upside down, in which we are convinced by a new study of Canadian geologists.
We understand: There is no difficulty in retelling the press release of the University of Toronto with the same name “Meteorite crash turned Earth inside out: study” , which is easily misunderstood. In fact, scientists have studied the crater of Sudbury, the second largest known on Earth.
A brief history of Sudbury Crater
A ten-kilometer cliff collided with the Earth at a speed of 40 km / s 1.8 billion years ago. The meteorite most likely evaporated, while also turning 27 thousand cubic kilometers of bark into steam. The depth of the resulting depression was approximately 30-40 km. Most of them settled around the impact for several hours, and it turned out that the upper crust was covered with condensed lower crust. The fact that it was exactly the impact of a meteorite was established by the increased iridium content that occurs in the Earth’s mantle (that is, very deeply) and in meteorites. So, in a sense, a piece of Earth really turned inside out.
News : Scientists have noticed an unusual nebula HuBi 1 in the constellation Snake, which causes alarm among astronomers. The observed portion of the interstellar medium, which is distinguished by its radiation or absorption against the general background of the sky, arose as a result of the fact that one of its stars “turned inside out” at the last instant of life. Similarly, the Sun will die, consider astrophysicists.
Understand: Original - blog entry of the astronomer Martin Guerrero. In 2018, Martin decided to take a photo of the HuBi 1 nebula, discovered in 1990 by the astronomers Hu and Bibo (and the name deliberately or accidentally sounds like Obi Wan, hello to Star Wars). And, looking at the photo, Martin first decided that he had messed with the technique, because the nebula seemed to be turned inside out. The “normal” nebula has a low ionization area, red in the photo, outside, and a high ionization area, blue or green, inside. HuBi 1 was the opposite.
HuBi 1 in the center, photo by Martin Guerrero
Additional research next year showed not only an unusual spectrum, but also the fact that the central star became noticeably less bright. According to photometric data from the archives, it was possible to establish that the star had faded ten thousand times since 1971. Simulations on a computer together with spectral data clarified the picture — the external part recombines due to the lack of ultraviolet radiation, and the central part is not ionized by photons, but experiences shock excitation from a substance dropped from a star. The substance blocks the light of a star for an external observer.
As a result, it turned out that the central star of the nebula experiences an infrequent case of a “second birth” - a late thermal flash, and moreover, slower than that of known similar stars (for example, the Sakurai object ).
Unusual journey of HuBi 1 according to the Hertzsprung-Russell diagram, illustration by Martin Guerrero
It is curious that the mass of the central star HuBi 1 was estimated at 1.1 times the mass of the Sun, so the probability of such a degeneration of our star may be non-zero. But since this can happen only after the red giant stage (after 7-8 billion years), little will be left of the inner planets of the solar system by that time.
Well, the last question worth mentioning concerned the concept of the hollow Earth ( example ). In general, when the conversation about the hollow Earth begins, the first thing I remember is the “Inhabited Island” of the Strugatsky brothers. One of the brothers was an astronomer; I am sure he was very pleased to invent a cosmology of the inside-out world. But in order to make the picture believable, the planet had to add some agent to the atmosphere, creating a completely monstrous refraction, when the horizon seems to be much higher than the observer, and to hide the Sun, planets and stars with constant cloudiness. Because the earth's history says that without any telescopes, even in times of antiquity, people not only established the Earth's sphericity, but were able to calculate the size of the Sun, Earth, Moon and the distances between them. As they did, a long and good story can be read here. Well, simple experiments, available to everyone, I recently laid out .
Hollow Earth Globe
Mercury inside out
News : The unusual "spotted" character of Mercury in terms of its chemical composition found a simple explanation - it turned out that the planet was actually turned inside out, as the rocks from the boundary between the mantle and the core were on its surface, said planetologists at a conference of geophysicists in Yokohama.
Understanding: With a modern search, finding a source of news is usually quick and easy. Typing in English something like "Mercury inside out Yokohama" we find a good publication retelling the real-life performance of NASA scientists in Yokohama.
')
Northern Volcanic Plains of Mercury, photo by NASA / JHUAPL / Carnegie Institution of Washington with enhanced colors
The interplanetary station MESSENGER discovered the “problem” of Mercury - regions with great geological diversity were difficult to explain without drawing on the hypothesis of melting of a heterogeneous mantle. An example of such a region is the Northern Volcanic Plains (pictured above). And a group of scientists of the Space Center. Johnson NASA conducted a series of experiments that emulate the conditions of the young Mercury. They took a mixture similar in composition to enstatite chondrites and subjected to pressures and temperatures that were supposed to be on the border of the core and mantle of the young Mercury. Temperatures are not called, and the pressure reached 50 thousand atmospheres. And it turned out that the same chemical composition at different temperatures and pressures gave different rocks, as was discovered on Mercury. Older regions were formed deeper than the boundary between the nucleus and the cortex, and younger regions — at a lesser depth. And how they came to the surface explains the hypothesis of a collision between Mercury and the planetesimal (or Venus), as a result of which Mercury lost most of the crust and upper layer of the mantle.
The earth inside out
News : An ancient collision turned the Earth inside out. A cosmic "pebble" the size of a mountain struck our planet about 1.8 billion years ago. In this part of the crust was simply stripped off, like a scalp. In essence, it was turned upside down, in which we are convinced by a new study of Canadian geologists.
We understand: There is no difficulty in retelling the press release of the University of Toronto with the same name “Meteorite crash turned Earth inside out: study” , which is easily misunderstood. In fact, scientists have studied the crater of Sudbury, the second largest known on Earth.
A brief history of Sudbury Crater
A ten-kilometer cliff collided with the Earth at a speed of 40 km / s 1.8 billion years ago. The meteorite most likely evaporated, while also turning 27 thousand cubic kilometers of bark into steam. The depth of the resulting depression was approximately 30-40 km. Most of them settled around the impact for several hours, and it turned out that the upper crust was covered with condensed lower crust. The fact that it was exactly the impact of a meteorite was established by the increased iridium content that occurs in the Earth’s mantle (that is, very deeply) and in meteorites. So, in a sense, a piece of Earth really turned inside out.
Nebula inside out
News : Scientists have noticed an unusual nebula HuBi 1 in the constellation Snake, which causes alarm among astronomers. The observed portion of the interstellar medium, which is distinguished by its radiation or absorption against the general background of the sky, arose as a result of the fact that one of its stars “turned inside out” at the last instant of life. Similarly, the Sun will die, consider astrophysicists.
Understand: Original - blog entry of the astronomer Martin Guerrero. In 2018, Martin decided to take a photo of the HuBi 1 nebula, discovered in 1990 by the astronomers Hu and Bibo (and the name deliberately or accidentally sounds like Obi Wan, hello to Star Wars). And, looking at the photo, Martin first decided that he had messed with the technique, because the nebula seemed to be turned inside out. The “normal” nebula has a low ionization area, red in the photo, outside, and a high ionization area, blue or green, inside. HuBi 1 was the opposite.
HuBi 1 in the center, photo by Martin Guerrero
Additional research next year showed not only an unusual spectrum, but also the fact that the central star became noticeably less bright. According to photometric data from the archives, it was possible to establish that the star had faded ten thousand times since 1971. Simulations on a computer together with spectral data clarified the picture — the external part recombines due to the lack of ultraviolet radiation, and the central part is not ionized by photons, but experiences shock excitation from a substance dropped from a star. The substance blocks the light of a star for an external observer.
As a result, it turned out that the central star of the nebula experiences an infrequent case of a “second birth” - a late thermal flash, and moreover, slower than that of known similar stars (for example, the Sakurai object ).
Unusual journey of HuBi 1 according to the Hertzsprung-Russell diagram, illustration by Martin Guerrero
It is curious that the mass of the central star HuBi 1 was estimated at 1.1 times the mass of the Sun, so the probability of such a degeneration of our star may be non-zero. But since this can happen only after the red giant stage (after 7-8 billion years), little will be left of the inner planets of the solar system by that time.
Hollow Earth
Well, the last question worth mentioning concerned the concept of the hollow Earth ( example ). In general, when the conversation about the hollow Earth begins, the first thing I remember is the “Inhabited Island” of the Strugatsky brothers. One of the brothers was an astronomer; I am sure he was very pleased to invent a cosmology of the inside-out world. But in order to make the picture believable, the planet had to add some agent to the atmosphere, creating a completely monstrous refraction, when the horizon seems to be much higher than the observer, and to hide the Sun, planets and stars with constant cloudiness. Because the earth's history says that without any telescopes, even in times of antiquity, people not only established the Earth's sphericity, but were able to calculate the size of the Sun, Earth, Moon and the distances between them. As they did, a long and good story can be read here. Well, simple experiments, available to everyone, I recently laid out .
Source: https://habr.com/ru/post/449898/
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