It's almost certainly not, and even if it was, the fact it's in a random spin and had its light sail permanently deployed would suggest that it's a knackered, dead probe.
>>4532 I like to think it was a superweapon, and those that sent it will now have to wait a decade or more to find out that they missed ever so slightly.
>The reason I contemplate the reconnaissance possibility is that the assumption that `Oumumua followed a random orbit requires the production of ~10^{15} such objects per star in our galaxy. This abundance is up to a hundred million times more than expected from the Solar System, based on a calculation that we did back in 2009. A surprisingly high overabundance, unless `Oumuamua is a targeted probe on a reconnaissance mission and not a member of a random population of objects.
>According to Loeb, that there’s also the fact that ‘Oumuamua’s orbit brought it to within 0.25 AU of the Sun, which is a good orbit for intercepting Earth without experiencing too much solar irradiation. In addition, it came to within 0.15 AU of Earth, which could have been the result of orbital corrections designed to facilitate a flyby.
>Jackson said the spectral data from 'Oumuamua looks like an asteroid or a comet, while that of a solar sail would look very different. The new paper proposes that the sail has been coated in interstellar dust, which obscures its true spectral signature.
>"Any functional spacecraft would almost certainly retract its solar sail once in interstellar space to prevent damage," Jackson said. "The sail is useless once away from a star so there would be no reason to leave it deployed. If it was then deployed again on entering the solar system it would be pristine. Even if it was left deployed the dust accumulation would be primarily on the leading side like bugs on a windshield."
>'Oumuamua also travels in a complex tumbling spin, but a functioning solar sail would have a much smoother path and obvious radiation-driven acceleration, Jackson said. Even the spinning motion of a damaged solar sail would be far more strongly influenced by the radiation forces than seen.
> "But one should not blindly accept this clever hypothesis when there is also a mundane (and a priori more likely) explanation for Oumuamua — namely that it's a comet or asteroid from afar."
> Coryn Bailer-Jones, an astronomer at the Max Planck Institute for Astronomy in Heidelberg, Germany, voiced similar objections. "In science," he said in an email, "we must ask ourselves, "Where is the evidence?, not "Where is the lack of evidence so that I can fit in any hypothesis that I like?"
The bit I find interesting is that it speeds up when it enters our solar system, which is highly irregular for an object that hasn't been sling shotted.