But so far officials say they have seen nothing that indicates intelligent alien life.
"I have not seen anything in those holdings to date that would suggest that there has been an alien visitation, an alien crash or anything like that," Ronald Moultrie, under secretary of defence for intelligence and security, said.
Sean Kirkpatrick, the director of the Pentagon's newly formed All-domain Anomaly Resolution Office (AARO), did not rule out the possibility of extraterrestrial life but said he was taking a scientific approach to the research.
"I would just say that we are structuring our analysis to be very thorough and rigorous. We will go through it all," he said.
"And as a physicist, I have to adhere to the scientific method, and I will follow that data and science wherever it goes."
A predictably cautious approach. But I don't believe, for a moment, that it will be followed "wherever it goes." To read more, click here.