Scientists have been puzzling over a mysterious object in space ever since it was first spotted tumbling past the sun in late 2017. Now a pair of Harvard researchers are raising the possibility that it’s an alien spacecraft. As they say in a paper to be published Nov. 12 in The Astrophysical Journal Letters, the object "may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization." In this interview with NBC News, famed astrophysicist Neil deGrasse Tyson shares his take on the subject.