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The visitor from the depths of space: a possible solution to the mystery

A new study claims that the asteroid Umoamua, which came from another solar system, is a fragment of a planet

By: Yonatan Shimoni, Davidson Institute

It is possible that the jets of water vapor act as a rocket engine and accelerate the asteroid. Illustration of Omuamoa | Source: NASA / ESA / STSCI /
It is possible that the jets of water vapor act as a rocket engine and accelerate the asteroid. Illustration of Omuamoa | Source: NASA / ESA / STSCI / (screenshot from the attached video)

In October 2017, astronomers from the Heilakala Observatory in Hawaii discovered for the first time a celestial element in our solar system that came from another solar system. This object is not a particularly large asteroid, whose diameter along the widest axis reaches several hundred meters. He was given the name 'Oumuamua, which in the Hawaiian language means "explorer" or "messenger".

Several clues have led researchers to conclude that Umoamua is a guest in our solar system. Its orbital characteristics, such as its speed or inclination from the Milky Way plane, differ from those of other asteroids and comets orbiting the Sun. In fact, calculating the shape of its orbit shows that it is also on its way out of our solar system. In addition, it moves around all its axes, which is an energy-intensive movement, since bodies tend to fixate over time on rotation around one central axis, like the Earth. The fact that Umuamua has not yet stabilized around one axis suggests that it started out with an extremely high energy, which may have allowed it to escape the gravity of another star. Also, its baguette-like shape has no equal in our solar system.

Many studies have tried to explain how Omoamua was formed. Among other things, there have been speculations that it is a fragment of a comet that was torn apart due to the gravitational force exerted on it by a planet, or even that it is nothing less than an alien ship. Now a new study claims that Umuamoa is a remnant of a planet from another solar system, which disintegrated after passing too close to its star, and could not withstand the strong gravitational forces acting on it.

It is possible that the jets of water vapor act as a rocket engine and accelerate the asteroid. Illustration of Omuamoa | Source: NASA / ESA / STSCI / SCIENCE PHOTO LIBRARY

Strong gravitational forces

To illustrate that this scenario is possible, researcher Yun Chan (Zhang) and her colleague Douglas Lin (Lin) performed computer simulations simulating the approach of bodies to a star weighing about half the mass of the Sun. They chose a star lighter than our sun, because light stars have a larger Roche limit: a range where, when a body penetrates it, the star's gravitational forces will overcome the internal forces that hold it together, and the body will break up. It is therefore more likely that a planet will break up near light stars.

In the simulations, bodies of various sizes, between a few hundred meters and a planet larger than Earth, were put into orbits that would bring them to a distance eighty times smaller than the distance between the orbit of the planet Hema and our Sun. At such a distance, tidal forces act on the planet - strong gravitational forces pull the side facing the star more strongly than the far side, thus stretching the body like rubber. After enough time the elongated body will disintegrate into many small parts, which look like omoamua.

Such a violent process could also explain why the asteroid orbited around all its axes. In addition, it could explain another observation: when Omoamua passed by our Sun, it accelerated. If it did form in a way similar to the one proposed by the researchers, it is possible that ice was trapped inside it when it was torn from the planet. As it passed near the sun, the ice evaporated and the jet of steam emitted from Umoamua acted on it like a rocket engine.

However, the Israeli astrophysicist Avraham (Abi) Loeb from Harvard University believes that the chance that Umuamoa is a fragment of a planet is not high. Astronomers estimate that there are many more objects like Omoamua in space, and for them to be formed "a star would need to produce a quadrillion (one million billion) such objects," Leib told the Science-News website. Tearing a planet apart like this is a rare process, because it will only happen if the planet passes through a very narrow zone: close enough to the star for the forces to act on it, but not too close, or the star will swallow it.

The study, therefore, showed a possible mechanism that explains how Omoumoa's baguette-shaped fragments, with high enough energy to escape from their own solar system, form. This mechanism is possible for a planet, a comet, or part of a disk that will form later into a planet. According to Lin, "Umoamua is only the tip of the iceberg. We expect that many more visitors with similar characteristics from interstellar space will pass through our solar system."

for the scientific article

More of the topic in Hayadan:

6 תגובות

  1. Well, I don't understand how anyone really believes this...and read it all before you comment!
    According to the aforementioned researchers, this is an asteroid that came from another solar system, from a planet that disintegrated. This is a hypothesis that has no foundation, and is essentially walking in circles around the conclusion that those researchers do not want to align with.
    It is noted that the object is characterized by high energy because it rotates on all its axes. The closest star to the Sun is Alpha Centauri 4.1 light years away, and a calculation of the object's orbit shows that it roughly came from the direction of Vega which is 25.05 light years away. That is, the object came from a distance of between 4 and 25 light years, and it managed to maintain a high energy of rotation in all axes from the time the planet disintegrated! Although space is quite empty, there is still friction and the effect of gravitational forces. Its speed in the solar system was 26.33 km/s. At this speed it left its star between 47,370 and 296,066 years ago, and it still has rotations on all axes. I think this indicates a collision or energy transfer at a time closer to the present day.
    In addition, the object received an unexplained acceleration that is impossible if it was an asteroid that behaves according to the forces of gravity alone, so they switched to the theory that it is a new type of body, which is suspended between a comet and an asteroid, and "assume" that the emission of this comet (gas) gave it the energy to change An orbit around the sun similar to the principle of a rocket engine.
    So why isn't it actually a comet? Because no emission and no tail from the bone was observed. In fact, according to their explanations, this gas is "invisible", even though the Hubble Space Telescope, which was also used for observations of the object, operates at wavelengths of visible, ultraviolet and infrared light. I would expect a gas that is heated to emit at least infrared radiation.
    Let's say hypothetically that it does emit a gas that moves it, but if a body rotates around all its axes, this emission in summary of all the energy is minimal or eliminated, because the emission changes direction all the time.
    In addition, comets are not driven at all by their emission. If you check, you will see that the tails of the comets are always perpendicular to the sun, because they are the result of a reaction of the ionized gas with the solar wind (with a certain roundness as a result of the comet's motion component) if they contributed to the momentum, they would always be parallel to the direction of the comet's motion.
    Add to that the object is 10 times brighter than comets, and what reflects more light than ice? That's right metal. And also that this elongated shape is not typical for comets or asteroids.
    No one pointed out that Avi Leib proposed an alternative theory that it was an unnatural object, perhaps alien?
    Please explain to me where my father and I are wrong.

  2. I didn't understand how there is ice on it if it traveled so close to the sun otherwise?

  3. Avi Leib is not the one who claimed that the source of the asteroid could be an alien ship..?

  4. First of all, for all the smart people who ask why we didn't "catch a ride" on the "asteroid", the reason is that we don't have such technology, at least not as far as the space agencies know. A rocket into space, and planning such missions takes years, and in addition to that, the object moves at high speed. He could not be reached. It might be possible to convert an existing project, but that would also take a lot of time and cause the original goal to be lost.
    What can be done is to try to design a system that will be on alert for interception. But again, the problem is the enormous distances and speeds of these objects, and then the price of the project, which we may not be able to use, because there is no way to predict when and where they will enter the solar system, will discourage any such project manager.

  5. Apparently it would be possible to launch a probe into its orbit in a collision course, land on it, dock on the surface and hitch a ride into interstellar space

  6. To all the smart scientists
    Try to use this bone to your advantage,
    Try to use it by installing sensors and or cameras on it that will give us information about track behavior and a lot more information.
    Imagination, maybe
    But you have to think about it.

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