Oumuamua: Avi Loeb says it may have been an alien solar-sail visitor (audio).

In this hour-long audio interview with the Planetary Society, Avi Loeb, the Frank B. Baird, Jr. Professor of Science at Harvard University, chats about why the first incoming object known to have originated outside our solar system might be a light-sail device – either a probe or a nav-buoy – built by an alien civilisation.