The year 2017 was of great importance because many revolutionary discoveries were made in space. One of the most significant events of 2017 was the arrival of the first interstellar object, first thought of as a comet, an asteroid, an alien spaceship and finally classified in the “stellar object” section. Discovered by a Hawaiian astronomer, it was quickly called”‘Oumuamua” (real name: 1I/ʻOumuamua), which means “a distant messenger coming first”, reflecting the origin of the mysterious object.
Astronomers believe they have finally traced the origin of the interstellar object. The cigar-shaped asteroid is believed to originate from the Pleiades group (near young stars), one of the closest places to Earth and better perceived by the naked eye. Astronomers think that Oumuamua was probably expelled from his star system, and sent to interstellar space, leading him to pass in front of us.
Studies conducted by different astronomers have shown that the mysterious object is made of ice with a carbon-rich surface and has an extremely unusual orbit. This one travels at about 26 km /s, since it left our solar system.
Oumuamua has been scanned using the Green Bank Telescope by astronomers from the Breakthrough Listen research program to detect possible extraterrestrial signs, but no intelligent signals have been identified so far, although further observations are planned, notes an article in the program.
A study published at that time on arXiv gives us an overview of the exact origin of’Oumuamua’.
In reconstructing the movement of the object, Fabo Feng, a post-doctoral researcher at the University of Hertfordshire, indicates that Oumuamua probably comes from a group of young moving stars, also known as the Local Association located near the Pleiades. Based on Oumuamua’s trajectory, this scientist simulated how the mysterious object could travel across the galaxy and compared it to the movements of nearby stars. The conclusion is that the object would have passed to about 16 light years of 109 stars.
Credits : NASA
The study notes that it is likely that when’Oumuamua was first expelled into space, he would have travelled at a speed sufficient to “detach” himself from the gravity of his star rather than at a much faster speed that would require even more energy. This means, according to the research, that the object should move relatively slowly at the beginning of its interstellar journey.
“Unlike most nearby stars, Oumuamua moves very slowly compared to the average motion of the rest of the galaxy. This suggests that he has only recently been travelling in interstellar space and has not had the opportunity to find many massive objects that accelerate him (thanks to gravity),” says the study.
In 2018, Oumuamua increased in speed, prompting some scientists to ask questions. See this article.
As for the asteroid initially ejected, this study considers as plausible scenarios that Oumuamua could have been ejected from a binary star system composed of two stars (two suns) in close orbit, explains Feng in an article written by the media The Conversation.
“Objects in orbit around one of the stars in a binary system will be strongly affected by the gravity of the other and thus can be more easily ejected from the system than if it had only one star.”
Finally, Feng points out how Oumuamua is probably just the tip of the iceberg. And that there are probably more than 46 million similar interstellar objects passing through the solar system each year.