Could an interstellar object that had flown into the solar system would itself stretch into a cylinder or not?
Asteroids are not cigar-shaped
Scientists will not calm down in any way - they continue to argue what the object was that flew three years ago through the solar system. Oumuamua - that's how he was called. “The messenger who arrived first from afar” means this in Hawaiian. And it sounds very ambiguous - with a clear hint of brothers in mind. This is, in fact, the dispute. Some consider the object to be a spaceship that has lost control. Or at least an automatic reconnaissance probe. Others claim that Oumuamua is an asteroid. Or some kind of comet.
Let me remind you. On October 19, 2017, astronomers from the University of Hawaii detected an object that was moving towards the Sun at a tremendous speed - 87.3 kilometers per second. The trajectory of the object was hyperbolic, which indicated that it was flying from some other star system.
It soon became clear that Oumuamua rotates, making one revolution in 7 hours and 18 minutes. And at the same time it changes the brightness. After analyzing the nature of the change, scientists realized that the object is very elongated and resembles a cigar, the length of which is about 10 times the diameter.
The length of the "cigar" was originally estimated at 400 meters, and the diameter, respectively, at 40 meters. NASA later clarified: Oumuamua is twice as long - 800 meters. The diameter is therefore 80 meters. The surface of the object is solid, with complex relief, possibly even metal. At least in places. Himself - red.
The cigar-shaped object could very well be a spaceship. At least in theory.
Promotional video:
The cylindrical shape gave enthusiasts - very serious scientists - the right to assert that Oumuamua was created and equipped by some brothers in mind. Since such - elongated - asteroids have never been seen before. And there shouldn't be any.
An example of such astronomers adhering to traditional views imagined Oumuamua.
Skeptics naturally doubted about the aliens. How the object became a cigar was not explained. And recently a corresponding explanation has appeared. It was provided by researchers from the Chinese Academy of Sciences and the University of California, Santa Cruz, which ScienceAlert links to.
The essence of the hypothesis: Oumuamua was "stretched" by gravitational forces. According to Douglas Lin and his Chinese colleague Yun Zhang, this could very well have happened at the moment when the object flew next to some massive body - a black hole, a star or even a large planet.
Simulations carried out by scientists have demonstrated that Oumuamua originally had a completely asteroidal shape. Or comet. That is, it was an unremarkable lump. I flew somewhere. In the immediate vicinity of a certain star, he began to "twist". As a result, the lump warmed up, melted in places and disintegrated into many fragments. They flew further in the form of an elongated group. After some time, the fragments stuck together, cooled down, forming a cigar-shaped object.
In a paper published in the journal Nature, scientists argue that comet Shoemaker-Levy, which in 1992 disintegrated into fragments in the vicinity of Jupiter under the influence of its gravitational forces, could stretch out and become a kind of Oumuamua.
Fragments of the comet fell on Jupiter without stuck together into a cigar. Because they were too close to the giant planet. They would have been a little further, would have flown past, and then they would have stuck together into a cigar. Like Oumuamua.
The scheme for the formation of Oumuamua - this was recently proposed by American and Chinese scientists.
Asteroids do not accelerate by themselves
- Our high-precision measurements showed that something else besides the attraction of the Sun and planets influenced the movement of Oumuamua, - these are the words of Marco Micheli from the European Space Agency Space Situational Awareness Near-Earth Object Coordination Center in Frascati, Italy) cited the NASA website.
Two years ago, Marco and his numerous colleagues (17 people) from different countries, including specialists from the American space agency, published an article in the journal Nature entitled "Non-gravitational acceleration in the trajectory of 1I / 2017 U1 (Oumuamua)." And they said in it that the "first interstellar asteroid", named Oumuamua, did not fly along a ballistic trajectory, like a projectile fired from a cannon, but from time to time accelerated. Like turning on the engines. And in the end, he moved differently than he followed according to Kepler's laws - the laws of celestial mechanics.
“We found clear signs that Oumuamua’s trajectory was determined not only by gravity,” echoed colleague Harold A. Weaver of The Johns Hopkins University Applied Physics Laboratory.
Inspired by the revelations of scientists, the enthusiasts concluded that the "alien" was still a spacecraft. What else? Once, he himself periodically accelerated.
The Americans and the Chinese - the authors of the hypothesis of the natural origin and elongation of Oumuamua - believe that jet jets of dust and gases that escaped from under the heated surface of an object when it flew near powerful heat sources could create thrust from time to time. For example, past some stars. In this Oumuamua was like a comet.
Where did the volatiles that formed the jet jets come from? They were sealed under the surface of an object when it stretched out and froze, scientists answer.
Oumuamua could launch reactive jets of volatile substances hidden under the surface.
What should I call you now?
So was Oumuamua a messenger from other stars? Or some kind of comet? Outside observers believe that both statements are flawed.
Where are the other "cigars" that the Americans and their Chinese counterparts are pioneering to make in the billions? Why don't they flicker past us? And the proposed process of turning lumps into cigars does not seem entirely convincing. As well as the idea that Oumuamua was emitting jet streams of matter. This really happens to comets. But why then, bypassing the Sun, the impetuous object did not release a single jet? At least nothing of the kind was noticed.
The hypothesis that Oumuamua was the creation of some extraterrestrial civilization is even more confusing - some kind of fantasy.
On the other hand, why not believe that Arthur Clarke's prophecy has come true. In his novel A Date with Rama, a “cigar” also flew to us, which nevertheless turned out to be a giant spaceship. Oumuamua is smaller than Rama, but the proportions are about the same. And the route is similar - in transit from the depths of the Universe.
The controversy continues. Winners are unlikely to be revealed. "The messenger who arrived first from afar" rushes away from the solar system - towards the constellation Pegasus. It has not been seen for a long time, even in space telescopes. In January 2019, Oumuamua passed Saturn, and in 2024 will fly over Pluto.
From far away for a long time
Scientists from a large group representing several of the world's leading research centers (MPIA Heidelberg, JPL, University of Hawaii, Tokyo Institute of Technology, ESA SSA-NEO Coordination Center, Rochester Institute of Technology, Southwest Research Institute, ESO) have estimated Oumuamua's trajectory. And they disputed the original assumption that he came from the constellation Lyra.
Using data and images obtained with the Gaia space telescope, scientists "plotted" their trajectory, naming four stars from which it could begin. Most of all, the red dwarf HIP 3757, which is located in the constellation Cetus 77 light years from the Sun, is suitable for the role of the home star of the "messenger". Another candidate is the Sun-like star HD 292249 from the constellation Unicorn. It is 135 light years away.
Calculations showed that Oumuamua could have flown from two more places - from the vicinity of the star 2MASS J0233 and the star NLTT 36959. One is located 66 light years from us in the constellation Cetus, the other in the constellation Virgo, 300 light years away. Both stars are also like the Sun.
Astronomers believe Oumuamua took 1 to 4 million years to reach the solar system.
VLADIMIR LAGOVSKY
