Sunday , May 29 2022

The mysterious body confirms what we already know. We know little about the universe



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Asteroid? The core of the comets? Alien Spacecraft?

Approximately one year after the discovery, the interstellar body Oumuamu is again the center of public and professional attention. Several scientists reanalyzed their unique properties. And he presented possible explanations, including really exotic.

Three recent studies of European and American scientists are particularly interesting. At the portal of the American Astronomical Society AAS Nova, the astronomer and editor Susanna Kohlero summed up their main points. First, let us briefly present the basic facts.

What it is?

The story began in October 2017. The telescope of the Haleakala Observatory in Hawaii Maui captured a foreign body that had been removed from the sun. The closest to him, about a quarter of the Sun-Earth distance, was still in the first decade of September. At first glance, nothing extraordinary, probably a planet. However, the reconstruction of the route showed that it had arrived from another star.

We first know the body. Though the theorists were thinking about them a long time ago, especially with comets. In the formal labeling of newly discovered space bodies, the letter was introduced as an interstellar abbreviation. Body 1I / 2017 was named to honor the place of Oumuamu's discovery, which in Hawaii is roughly a "messenger of the ancient past."

In this way, the 1/2017 U1 Oumuamua body (blue circle) appeared on the composite of images from the large telescopes VLT and Gemini South.

photogallery / 4

In this way, the 1/2017 U1 Oumuamua body (blue circle) appeared on the composite of images from the large telescopes VLT and Gemini South.

Source: ESO / K. Meech et al.

Strange form, weird movement

Short-term bright changes of the Oumuamu brilliance were observed when rotation of the body with an unusual shape. It's like it's on the runway. Initially, it was considered that the length / width ratio is 10: 1, currently at least 5: 1. The length is estimated at hundreds of meters, widths to tens and up to tens of meters. The body can be strongly flattened.

The reddish color and relative darkness of the surface result from the composition of rocks, metals, azda with the addition of organic substances and "black" ice. That would give testimony to the planet. However, the observed movement of the body could not be explained only gravitationally. It was faster than the sun. The acceleration value depends on the "Oumuamu" impulse from the Sun.

In this way, the 1/2017 U1 Oumuamua body (blue circle) appeared on the composite of images from the large telescopes VLT and Gemini South.

photogallery / 4

In this way, the 1/2017 U1 Oumuamua body (blue circle) appeared on the composite of images from the large telescopes VLT and Gemini South.

Source: ESO / K. Meech et al.

Comet? just

This would indicate a flux effect caused by gas extraction directed after heating frozen substances on or near the body through sunlight at and after approaching the sun. In this case, we should simply deal with the core of the comet.

Things are more complicated. Roman Rafikov of Cambridge University (United Kingdom) and Princeton Institute of Advanced Studies, New Jersey, noted that Oumuamu had no gas leakage, no coma (gas shell), no tail or gas tail. If they were not visible, it would accelerate the rotation. To the extent that the body would disintegrate with the effect of centrifugal forces during the passage through the solar system.

Where did he come from?

The extrapolation from the back of Oumuamua Sprava led to a loss. I could not tell where this body actually came. His career is not based on any known star. This acceleration of body movement was helped.

Previous extrapolations only considered gravitational effects. Given the gravity-free acceleration, together with the 7 million DR2 orbits database based on Gaia's European satellite measurements, the first promising indices have been raised in this regard.

The artistic vision of the shape of the Oumuamu interstellar body, viewed from another angle, is a little out of place.

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The artistic vision of the shape of the Oumuamu interstellar body, viewed from another angle, is a little out of place.

Source: ESO / M. Kornmesser

Dozens of star houses

Coryn Bailer-Jones of the Max Planck Institute for Astronomy in Heidelberg, Germany, identified four nearby stars that are being considered. The most popular are the HIP 3757 red dwarf, around which the body passed about a million years ago, and the HD 292249 sunshade around which approximately 3.8 million years passed.

But it applies only if "Oumuamua is constantly moving in the same way." Coryna Bailera-Jones said that every million years Oumuamua encounters gravitationally about 20 stars and brown dwarfs and Jupiter planes) when flying in 3.26 light years.

And now for science fiction …

Abraham Loeb of the Harvard-Smithsonian astrophysics center in Cambridge (Massachusetts, USA) is a specialist in unorthodox assumptions. He did not hesitate even at Oumuamu. With colleague Shmuel Bialym suggested: the observed acceleration of this body can be explained when it comes to a type of "sailing sailing".

I mean, the body that acts on radiation pressure. Oumuamu may even have a much more extreme form than I mentioned. Exactly: it would be extremely thin. In case of a large area, solar radiation would exert pressure to explain the acceleration. According to the hypothesis authors, a large but thin body could also bear an interstellar flight.

Pairs do not claim that "Oumuamu is a sunny alien sailboat." Formations of this type are also naturally found in interstellar matter, but the artificial origin of this body does not exclude. the cosmic horizon.

… and back to reality

Oumuamu remains a mystery. Apparently, it will remain. During his passage through the solar system, he failed to get clear visions. Specifically, we have failed, and we have not been able to do it, because we have nothing yet. They're coming back to the stars.

Although the case is suggestively mentioned in the science fiction novel by Arthur Clark Meeting with Rama, the rational approach to preaching "to remain on the ground." Without further evidence, it is still necessary to conclude that it was a natural body that I have not met before. At least I do not know.

Space reminder

But everything is a serious reminder. In March 1989, Planet 4581 Asclepius flew to a point where the Earth was only six hours earlier. Their collision would release energy of 600 megaton TNT. But we discovered the planet nine days after the biggest approach of our planet. We could not have expected to "fall on our heads".

The Oumuamua, similarly discovered (even over a month) after passing through the solar system, reminds us that we do not need to know what is happening in our wider cosmic house. The less we can effectively influence them. It's beyond our control.

In the weak state of our cosmic technical infrastructure, due to the unfortunate slowdown in its development, we are essentially still releasing the fate of the universe. Either as a natural body, a collision course with the Earth, or a stranger with unknown intentions.

Romain Rafik's study was published in The Astrophysical Journal Letters. Coryna Bailera-Jones has published her research in The Astronomical Journal. Eventually, Shmuel Bialy and Abraham Loeb filed their study in the ArXiv Internet Archive, according to The Astrophysical Journal Letters.

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