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Is Oumuamua an alien visitor created by intelligent life?
Artistic imagination of OuMuamua (Image source: wiki)
On October 19, 2017, the Pan-Star Survey telescope spotted an uninvited guest, just 33 million kilometers from Earth. At the time, astronomers thought it was a comet, but its "tail" was not observed later, and it can be concluded that its main body is not a comet made of ice cubes, but more like an asteroid made of rocks.
On March 17, 2021, researchers from the University of Arizona concluded that the uninvited guest was actually part of an Exo-pluto.
What is the origin of this uninvited guest? Why, years on, is it that the scientific community still hasn't stopped talking about it? What kind of charm does it have?
Images of "uninvited guests" were observed on October 28, 2017
(Image source: wiki)
The first exo-celestial object observed by humans
Scientists have not observed the "uninvited guest" for a few days, and they are extremely excited - its speed is as high as 87.71 km/s when it is closest to the sun. Scientists have even calculated that when it was farther away from the sun 100 years ago, it was still at a speed of 26.33 km/s relative to the sun, which has far exceeded the third cosmic speed (16.7 km/s). Its orbital eccentricity reached 1.2, the highest ever observed.
We know that an orbit with an eccentricity greater than 1 is a hyperbola. When a celestial body from distant space passes by with the sun, a large deflection occurs, and then it flies dashingly into the vast expanse of deep space. Although some celestial bodies have large eccentricity in their orbits, it is likely to be caused by the gravitational slingshot effect of large planets in the solar system. However, none of the large planets that exist in the solar system have the ability to increase the orbit of any celestial body to an eccentricity of 1.2.
Based on the above two points, it can be basically concluded that this "uninvited guest" came from outside the solar system, which is the first extrasocient object observed by humans to visit the solar system.
An eccentricity of 0 is a circular track, an elliptical track between 0 and 1 (red), a value of 1 forms a parabola (green), and a hyperbola greater than 1 (blue) (Image: wiki)
What is even more puzzling is that its brightness changes periodically, alternating every 7.3 hours (8.1 hours). It shows that it is likely to be a narrow and long shape, and it is constantly flipping in space.
Narrow and elongated shape? No such asteroids have been observed before this.
The picture on the right shows the photometric curve of Oumuamua, and the figure on the left is inferred from the photometric curve (Image source: wiki)
Omuam: Don't because I'm long
Just say I'm a spaceship
The narrow shape is so "sci-fi" that many people, including scientists, have asked if it could be a spaceship sent by aliens to visit the solar system. Others immediately thought of science fiction writer Clarke's Rendezvous with Rama, proposing to name it "Rama."
Meet Rama is a 1972 book by Clarke that tells the story of "an alien spaceship that broke into the solar system in 2130 and humans sent an expedition to investigate." Unfortunately, science fiction is only science fiction after all, and in reality, human beings have not yet had the means to go to the first line to detect this extraterrestrial object.
Eventually, since the object was discovered at the Hawaiian Observatory, the discoverer named it Oumuamua in the local Hawaiian vernacular, meaning "the first messenger from afar," which translates to Chinese is "Oumuamua."
Now we know that Oumuamua probably set off from Vega 600,000 years ago and came to us. It could also be a cosmic "wanderer" from more distant deep space, only to have skimmed over Vega 600,000 years ago.
Clarke's Meeting with Rama
(Image source: laptrinhx.com)
I have to say that in the vast universe, human beings are still a "baby". We do not have the ability to install various "cameras" in the solar system, lay down the "Skynet Project", and not miss any fish that have slipped through the net. When we found Oumuamua, it had already passed the perihelion, drifted away from us, and began the next leg of the journey.
When scientists studied Oumuamua's orbit through continuous observation, they found a more mysterious place.
Is Oumuamua a light-sail spaceship? Really, I don't believe it
On June 27, 2018, astronomers discovered an anomalous trajectory in Oumuamua— which was quietly accelerating. It seems that either it is motivated by itself or it is subject to additional force. Indeed, some comets may exhibit the phenomenon that, after being illuminated by the sun, comets will spew out some gas, changing the path to some extent, which is known as the "rocket effect" of comets.
But as we mentioned earlier: Oumuamua has no "tail", not a comet! For a time, the speculation that Oumuamua was an alien spaceship was noisy for a while.
Oumuamua's trajectory within the solar system (Image source: wiki)
Among them, the most representative opinion comes from Avi Loeb, the head of the astronomy department at Harvard University. He even wrote a book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, to promote his views. In the book, published this year, Avi Loeb insists that Oumuamua is an alien visitor created by intelligent life, even though most of his peers scoff at his ideas.
Avi Loeb: Aliens: The First Signs of Intelligent Life Beyond Earth (Credit: wiki)
Avi Loeb argues that since Oumuamua is not accelerating by jet like a comet, it can only be assumed that it is a "light sail ship". According to Avi Loeb, only by assuming that Oumuamua is a flat sheet of less than 1 millimeter, so that it will have a very large area-to-mass ratio, the sun's light pressure will help it "accelerate". He introduced his theory this way:
"The only way to understand the strange acceleration of Oumuamua without resorting to some kind of imperceptible jet is to assume that the object is propelled by solar radiation— essentially photons bouncing off its surface." Moreover, only with extremely low density and relatively large surface area can it be propelled by solar radiation, which is the only way, and that is that it is very thin (less than 1 mm thick). Such an object would act as a sail – driven by light rather than wind. Nature does not produce such sails, only intelligent life will make them. Therefore, Oumuamua must have been designed, built and launched by extraterrestrial intelligent life. ”
Avi Loeb envisioned a "light sail spaceship" (Image: wiki)
Most astronomers agree that Avi Loeb's conclusion was too impetuous. In fact, he is already a "habitual offender", and Avi Loeb seems to be the spokesperson for the "light sail" theory, always using "light sail" on different occasions to explain some astronomical phenomena.
In recent years in particular, some tycoons, including Russian billionaire Uri Milner, have approached him to design the first human spaceship, so he has spoken more and more about such topics as the sea of stars, and he has always been unsurprisingly deadly. Therefore, although he is in a high position of power, his remarks can only be used as a family's words.
Avi Loeb poses at an observatory near his office in Cambridge, Massachusetts (Credit: Washinton Post)
Science pays attention to empirical evidence, but unfortunately, we have been unable to catch up with Omomo, we can't land in Omomo, have a close contact with it, and observe what it really is.
Whether it is a comet, a rock asteroid, or a "light sail", it is just our conjecture about Oumuamua. In science, conjecture is not an unrealistic fantasy, and as long as it is in line with the facts, it can be trusted.
OuMuamua's Past and Present Lives (Video Source: phys.org)
Does Oumuamoo look like a big cookie?
On March 17, 2021, several researchers at the University of Arizona proposed a new hypothesis: Oumuamua is actually part of an exo-Pluto.
Pluto is one of the most typical dwarf planets, and there may be thousands of Pluto-like dwarf planets in the Kuiper Belt (the cold region of the solar system beyond Neptune's orbit, sometimes referred to as the third zone of the solar system) whose surfaces are covered with solid nitrogen.
In the same way, around other stars, there must be such "exoplanets" distributed farther away, and when they are hit, they may be knocked out of a fragment of solid nitrogen surface. After a long astronomical period, after some solid nitrogen volatilization, this fragment will become flattened, until it eventually becomes the shape of a thin disk that is now closer to that of a thin disk.
Pluto's surface is made up of more than 98% nitrogen ice, trace amounts of methane and carbon monoxide (Image: wiki)
When Oumuamua enters the solar system, under the illumination of the sun, the solid nitrogen will volatilize slightly, although it will not see a clear "comet tail" like a comet, but it is enough to make it produce a "rocket effect" to accelerate it.
Scientists at the University of Arizona calculated that a thin disk form of Oumuamua was enough to produce the observed acceleration effect. They were very excited: "It was an exciting moment when we realized that a solid piece of nitrogen was much more reflective than people thought, which made the smaller dwarf planet fragments stronger than the comet's rocket effect, which would give Oumuamua a bigger push." ”
Oumuamua may be a thin plate, which also looks a bit like a large cookie
(Image source: William Hartman, Institute of Planetary Sciences, Tucson, Arizona)
At present, the "nitrogen ice" hypothesis is most accepted by the scientific community. But isn't it possible to completely negate the "alien hypothesis"? Not necessarily. We look forward to further discoveries by astronomers.
On the contrary, after Oumuamua, we have found some uninvited guests from outside the solar system, such as the extra-comet Borisov (2I/Borisov). With the improvement of human observation capabilities, we are more and more aware that our universe is not as deserted as imagined. Or the machine? Everything may have to be answered by time. Just as navigators do not stop sailing because of the reefs near the sea, nor do we stop exploring because of a momentary confusion, you know, our journey will always be a sea of stars.
Will Oumuamua be a spaceship? (Image source: https://abagond.wordpress.com/2017/11/25/oumuamua/)
bibliography:
[1] Alan P. Jackson et al. 1I/'Oumuamua as an N 2 ice fragment of an exo‐Pluto surface: I. Size and Compositional Constraints, Journal of Geophysical Research: Planets (2021). DOI: 10.1029/2020JE006706
[2] S. J Desch et al. 1I/'Oumuamua as an N 2 ice fragment of an exo‐pluto surface II: Generation of N 2 ice fragments and the origin of 'Oumuamua, Journal of Geophysical Research: Planets (2021). DOI: 10.1029/2020JE006807
[3] Harvard’s top astronomer says an alien ship may be among us（https://web.archive.org/web/20190205154635/https://www.nola.com/education/2019/02/harvards-top-astronomer-says-an-alien-ship-may-be-among-us.html）
[4] Discovery of a Meteor of Interstellar Origin（https://arxiv.org/abs/1904.07224）
Author Affilications: Science Fiction Professional Committee of Jiangsu Science Writers Association
Further reading:
The revelation of "Patrolling The Little Demon" and "Big Cigar" | Popular Science Times
The Millennium Feud between Human Beings and "Perpetual Motion Machines" (5): How to Avoid Falling into the Trap of "Perpetual Motion Machines"|? Lu Chao
The Millennium Feud between Mankind and the "Perpetual Motion Machine" (IV): Zero Point Energy? Time crystals? Is it science or science fiction? | Lu Chao
The Millennium Feud between Mankind and the "Perpetual Motion Machine" (III): The Road of "Carrying" Energy Full of "Bumps" | Lu Chao
The Millennium Feud between Mankind and the "Perpetual Motion Machine" (II): Is there "extra" energy |? Lu Chao
The thousand-year feud between mankind and the "perpetual motion machine" (1): wooden kite, wooden cow and flowing horse, magic wheel... | Lu Chao
Background: Lu Chao, the author of this article, is the deputy director of the Science Fiction Professional Committee of the Jiangsu Science Writers Association, and a member of the Jiangsu Science Writers Association. Graduated from the Department of Physics of Nanjing University, his representative work "Grimace Chemistry Class - Element Family" was listed as the "IYPT 2019 Excellent Popular Science Book" bibliography of the Chinese Chemical Society, and won the first prize of the 10th Jiangsu Provincial Excellent Popular Science Works. Article published on April 13, 2021 on the WeChat public account Science Compound (Thanks!) Just passed by the sun, the following is a review of the earthlings' exploration of me), the voice of the wind and clouds is authorized to reprint.
Editor-in-Charge: Sun Yuan