Considering an artificial origin, one possibility is that
‘Oumuamua is a lightsail, floating in interstellar space as a debris
from an advanced technological equipment (Loeb 2018).
Lightsails with similar dimensions have been designed and
constructed by our own civilization, including the IKAROS
project and the Starshot Initiative2
. The lightsail technology
might be abundantly used for transportation of cargos
between planets (Guillochon & Loeb 2015) or between stars
(Lingam & Loeb 2017). In the former case, dynamical ejection
from a planetary System could result in space debris of
equipment that is not operational any more 3
(Loeb 2018),
and is floating at the characteristic speed of stars relative
to each other in the Solar neighborhood. This would account
for the various anomalies of ‘Oumuamua, such as the
unusual geometry inferred from its lightcurve