A couple of scientists have a new take on a mysterious space object that was spotted tumbling past the Sun late last year. Astronomers named it Oumuamua. That's Hawaiian for scout or messenger from our past. The stadium-sized thing sped up as it shot past the Sun. Now, two scientists from Harvard say the object that came from outside our solar system might be an alien spacecraft. In a paper they'll present next week, they write that it might be "a fully operational probe sent intentionally to Earth vicinity by an alien civilization." Whatever it is, it's left the solar system and telescopes can't find it.