Verification of facts, reality of the field: 'Oumuamua: asteroid, comet or extraterrestrial spacecraft?

Image of the artist from Oumuamua by the European Observatory by the Southern.

On October 19, 2017, astronomers using the pan-lift telescope instrument and rapid reaction system (Pan-STARRS) 1 in Maui, Hawaii, noticed the bursting of an object unusual. from the Lyra constellation, about 32 million km from the Earth, crossing the solar system towards an unknown destination. It was too small to appear as more than a mere point of light, even on the big telescopes, but it obviously involved an unusually elongated object that was spinning around at once. An axis and tilted in space, since its brightness varied considerably every 7-8 hours – the brightest when it is all its length facing the Earth, almost invisible when it points to the Earth. He was driving more than 87 km / second – fast enough to escape the gravity of the sun. Scientists dubbed it "Oumuamua, Hawaiian for" scout "or" a messenger sent from afar to join us ", and concluded that the reddish-brown rock was shaped like a cigar – about 800 m long and 80 m wide; Extreme proportions never seen before – the first interstellar object ever seen in the solar system.

Was it an asteroid?

Scientists first badumed that it was a comet, but they also noted that it did not present a visible "coma" (atmosphere of dust and gas around the nucleus of a comet) or "tail" (elongated cloud that rises from the sun), signature identifiers of comets as they approach the inner solar system. In an article published in Nature in November 2017, the team that discovered 'Oumuamua with the Pan-STARRS 1 telescope said in color and with its imputed properties that' Oumuamua resembled known asteroids. It could have come from the Vega star in Lyra, known to have a disc of debris; However, "the possibility that" Oumuamua revolves around the galaxy for billions of years can not be ruled out. "

Or was it a comet?

In June 2018, Professor Marco Micheli of SSA-NEO of the European Space Agency The Frascati Coordination Center in Italy has argued for the fact that Oumuamua is a comet – and has thus proposed a new way of detecting comets. In 2018, the Hubble Space Telescope noted that "Oumuamua was picking up speed – it had more than 40,000 km ahead of its expected trajectory," and Dr. Micheli said that "his movement had an impact. other than the gravitational forces of the Sun and the planets. "If the acceleration of Oumuamua was due to the emission of volatile substances or" degbading "(as happens with comets), the fact that was not visible as a tail was due to the fact that the dust itself The core of this comet was probably "made of large grains too heavy to be carried away by gas," Dr. Micheli told The Indian Express.

Maybe a spaceship?

In an article accepted for publication in The Astrophysical Journal Letters, Abraham Loeb, Director of Harvard's Department of Astronomy, and his colleague Shmuel Bialy badert that a "more exotic scenario [that explains ‘Oumuamua’s sudden acceleration] is that- ci: "Oumuamua can be a fully operational probe, intentionally sent near the Earth by an extraterrestrial civilization." The authors say that they "discuss the possible origins of such an object, including the possibility that It is a sail of light [a type of spacecraft propulsion device] of artificial origin.

The possibility that Oumamua was an extraterrestrial spacecraft had been discussed and dismissed in the first paper written on it. "Our observations are entirely consistent with the fact that it is a natural object," said Dr. Karen J. Meech, chief of the company. Pan-STARRS 1 team, according to the New York Times, a year ago.

" Like most scientists, I'd like there must be compelling evidence of extraterrestrial life, but that's not it, "said Alan Fitzsimmons, an astrophysicist, quoted by AFP. Dr. Katherine Mack, theoretical astrophysicist, tweeted: "… Scientists are perfectly happy to publish a strange idea if it has any chance of not getting it wrong. But until all the other possibilities have been exhausted a dozen times, even the authors probably do not believe it. "The American physicist Don Lincoln wrote for CNN that, although the hypothesis is not" ruthless madness, "it was" very unlikely "and invoked the Standard of Sagan, aphorism of astronomer Carl Sagan according to which "extraordinary claims require extraordinary evidence"

The Bialy newspaper, quoted by AFP, reportedly stated: "I would not say that I" believe "that it is sent by extraterrestrials, because I am a scientist, not a believer, I rely on evidence to propose a possible physical explanation of the phenomena observed. "

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