On the Possibility of an Artificial Origin for `Oumuamua

The first large interstellar object discovered near Earth, `Oumuamua, showed half a dozen anomalies relative to comets or asteroids in the Solar system. All natural-origin interpretations of the Oumuamua anomalies contemplated objects of a type never-seen-before, such as: a porous cloud of dust particles, a tidal disruption fragment or exotic icebergs made of pure hydrogen or pure nitrogen. Each of these natural-origin models has major quantitative shortcomings, and so the possibility of an artificial origin for `Oumuamua must be considered. The Galileo Project aims to collect new data that will identify the nature of `Oumuamua-like objects in the coming years.Comment: 17 pages, 8 figures, accepted for publication as a review paper in the journal Astrobiolog