Oumuamua: Why some Harvard scientists say this could be an object of "extraterrestrial civilization"

When they saw it for the first time, in October 2017, several telescopes followed their trajectory for three nights, until they lost sight of it.

It was not a normal object. It measured 400 meters long, its width was ten times smaller and its surface was reddish. It was spinning fast, had a chaotic trajectory and its luminosity changed abruptly.

Those who first observed it, astronomers of the Pan STARRS continuous sounding system from the University of Hawaii, gave it its name, Oumuamua, which means "messenger from far who arrives first "in Hawaiian.

At first, the discussion of what Oumuamua gave was two possible answers: a comet or an asteroid.

"We have tested many plausible alternatives and the most practical is that Oumuamua is a comet and the gases emanating from its surface cause small variations in its trajectory," said David Farnochhia of NASA's Jet Propulsion Laboratory.

Others, however, said that it was not a comet because in the observations they did not detect the tail characteristic of dust particles and ice that these travelers usually have space.

Dr. Wes Fraser, of Queen's University in Belfast, said last February that his strange movement was probably due to another object at some point in his history.

Now, a new study by scientists at the Harvard-Smithsonian Center for Astrophysics in the United States indicates that Oumuamua could have been created by a natural process "still unknown in interstellar space". [ISM, por sus siglas en inglés] or on proto-planetary disks. "

But another option that they are considering isWhat its origin may be "artificial".

"A fully operational probe"

By saying "artificial origin", astronomers Shmuel Bialy and Abraham Loeb, authors of the new study published in the journal Astrophysical Journal Letters, mean that "Oumuamua it can be a fully operational probe sent intentionally to the vicinity of the Earth by an extraterrestrial civilization"

Or it may be "advanced technological equipment", especially a solar sail, a device powered by solar radiation or solar wind plasma.

Bialy and Loeb come to this conclusion because of the unusual speed and trajectory that the telescopes were able to capture in Oumuamua during the three nights of their observation.

"This is the first object discovered in the solar system that originated outside the solar system." Since its discovery, Oumuamua has shown unusual features, making it a rare item, belonging to a class of objects never seen before, "Loeb told the BBC.

"What is the excess of acceleration of Oumuamua could cause? It is the fundamental question to which we try to answer, if it is not the tail of a kite that pushes it, what else could it be? We propose that it is solar radiation. " explained the scientist.

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Loeb compares Oumuamua to the solar sails created by our civilization, such as IKAROS, the first interplanetary probe powered by a solar sail, launched in 2010 by the Japan Aerospace Exploration Agency (JAXA) on the planet Venus. .

"If (Oumuamua) is part of a collection of objects, there must be more than we will discover in the future. Only a fraction of interstellar objects will be technological vestiges of an extraterrestrial civilization. But we must examine everything that enters the solar system from interstellar space to know the true nature of Oumuamua or other mysterious objects, "said the scientist.

A study "totally defective"

"I am not very convinced and I sincerely believe that the study is pretty defective […] Carl Sagan once said: "Extraordinary demands require extraordinary evidence" and this document clearly lacks evidence and there is no extraordinary evidence, "said Alan Jackson, a member of the Planetary Science Center of the 39, University of Toronto, CNN.

Jackson believes that if Oumuamua was a solar sail, it would be slimmer than what the authors think of the investigation.

Moreover, he asserts that if it was a working vessel "I would have a much softer driving and an acceleration obviously caused by radiation. "And in case it gets damaged, Jackson says his movement"would be much more influenced by radiation forces from what you see. "

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Bialy and Loeb state in their article that the object observations made by the telescopes "are not conclusive enough to give a clear picture of Oumuamua, and that only one can speculate on its geometry and its possible nature ".

"Although periodic variations are observed in its apparent magnitude, there are still too many degrees of freedom for example, the angle of observation, non-uniformly reflecting, etc. to clearly define its geometry. "

Alan Fitzsimmons, an astrophysicist at Queen's University in Belfast, pointed this out in an interview with AFP: "Some of the arguments in this study they are based on numbers with big uncertainties"

On her Twitter account, astrophysicist Katie Mack of the University of North Carolina said: "Scientists are happy to publish an extravagant idea if they have not the slightest" possibility "to make a mistake, they do not create it until the other possibilities have been exhausted a dozen times."

Is Oumuamua proof that life exists on other planets? Loeb answered this question to the BBC: "I am Sherlock Holmes' maxim:" When you eliminate any logical solution to a problem, the illogical, although impossible, is invariably true. "

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