{"id":18283,"date":"2018-11-06T19:02:30","date_gmt":"2018-11-06T11:02:30","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/oumuamua-oh-my-was-interstellar-object-actually-an-alien-solar-sail-not-so-fast\/"},"modified":"2018-11-06T19:02:30","modified_gmt":"2018-11-06T11:02:30","slug":"oumuamua-oh-my-was-interstellar-object-actually-an-alien-solar-sail-not-so-fast","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/oumuamua-oh-my-was-interstellar-object-actually-an-alien-solar-sail-not-so-fast\/","title":{"rendered":"\u2018Oumuamua, oh my! Was interstellar object actually an alien solar sail? Not so fast"},"content":{"rendered":"
\"Oumuamua\"
An artist\u2019s conception shows what the interstellar asteroid Oumuamua might look like. Or does it actually look more an alien light sail? (ESO Illustration \/ M. Kornmesser)<\/figcaption><\/figure>\n

\u2018Oumuamua is long gone from the inner solar system, but the mystery surrounding the interstellar interloper has been rekindled, thanks to a research paper written by two Harvard astronomers.<\/p>\n

The paper, suggesting that the cigar-shaped object could have been an alien light sail, sparked headlines as well as skepticism from colleagues claiming that the astronomers were jumping to conclusions.<\/p>\n

Among the skeptics is Doug Vakoch, who heads up METI, a San Francisco-based organization devoted to the study of alien contact. (The acronym stands for \u201cMessaging Extraterrestrial Intelligence.\u201d)<\/p>\n

\u201cI\u2019d love to think that \u2018Oumuamua<\/span> is an extraterrestrial spacecraft that whipped past Earth, propelled by a stream of photons hitting its solar sail. But we need to be wary of conjuring up an explanation that fits the data gathered at one point in time, when we have no opportunity for follow-up observations,\u201d Vakoch told me in an email.<\/p>\n

The claims from Shmuel Bialy and Avi Loeb of the Harvard-Smithsonian Center for Astrophysics are based on an analysis of \u2018Oumuamua\u2019s orbital trajectory, which brought it inward from interstellar space, around the sun, and then back outward in late 2017.<\/p>\n

Researchers found that the object was subject to a bit of extra acceleration that couldn\u2019t be explained by gravitational influences.<\/p>\n

If \u2018Oumuaumua (which was given a Hawaiian name meaning \u201ca messenger from afar arriving first\u201d) was a comet, the extra push might have been caused by the rocket-style effect of outgassing. And in fact that\u2019s exactly what scientists surmised this summer, based on an analysis they published in the journal Nature.<\/p>\n

Bialy and Loeb, however, say \u2018Oumuamua showed no outward signs of outgassing while it was under observation. Instead, they consider whether the acceleration could have been caused by solar radiation pressure on the object. Their calculations showed that such could be the case, but only if the object was a broad sheet of material less than a millimeter thick.<\/p>\n

\u201cOne possibility is that \u2018Oumuamua is a lightsail, floating in interstellar space as a [piece of] debris from advanced technological equipment,\u201d the authors write. Such a sheet could have survived the trip from another star system and would account for the object\u2019s unusual dimensions, they say.<\/p>\n

\u201cAlternatively, a more exotic scenario is that \u2018Oumuamua may be a fully operational probe sent intentionally<\/em> to Earth vicinity by an alien civilization,\u201d they add.<\/p>\n