You’d have to be living on another planet not to have heard one of the biggest news stories in recent times: After years of denial, it turns out that the US government has a secret program, researching and investigating UFOs.

The conspiracy theorists were right all along.

The story broke in December 2017 and generated unprecedented mainstream media coverage of the UFO phenomenon, which continues to this day, as the story continues to unfold. This coverage includes The Post’s new docu-series “The Basement Office,” which delves into this story as part of a wider investigation of the UFO mystery.

The Pentagon’s secret UFO program was called AATIP — Advanced Aerospace Threat Identification Program. The title cleverly blurred the lines between next-generation aviation threats and the phenomena they were really studying. Maybe as an unintended consequence, but perhaps by design, the cryptic title also kept the program hidden from the numerous people who make Freedom of Information Act requests about “UFOs.” AATIP was set up in 2007, largely on the initiative of the then-Senate majority leader, Harry Reid. When AATIP’s existence was revealed, Reid tweeted: “The truth is out there. Seriously.”

Related revelations and developments came thick and fast. Details were released of multiple events where UFOs have been tracked on radar and chased by military jets, including a November 2004 incident where the USS Nimitz carrier strike group was buzzed by multiple UFOs. Videos of three of these spectacular midair encounters have been made public, though many more have yet to be released. The Senate Armed Services Committee investigated the USS Nimitz incident last year and interviewed some of the pilots and radar operators. Also last year, the Defense Intelligence Agency briefed Congress on AATIP’s work.

In a Jan. 9, 2018, letter to John McCain — copied to other senior congressional figures and to key committees — the DIA disclosed that they had researched anti-gravity, warp drives, wormholes and other theoretical physics concepts needed for interstellar travel, as part of an effort to understand what they termed “foreign advanced aerospace weapon threats.” It raised the question “How foreign is foreign?” — did they mean Russia, China, or somewhere considerably farther afield?

In April of this year, the Navy announced they would issue new guidance to pilots who encountered UFOs, following a recent upsurge in “incursions” by “unidentified aircraft.” Then, just last week, The Post secured a stunning admission from the DOD that AATIP investigated “unidentified aerial phenomena” — a phrase they had previously been very careful to avoid. This bombshell revelation was the final proof that this had never been about Russian or Chinese aircraft, missiles and drones. Unidentified aerial phenomena (UAP) is the accepted government, military and intelligence community term for what the public calls UFOs.

When I worked on this issue for the UK’s Ministry of Defence, we used “UAP” in our internal policy discussions, thus avoiding the pop-culture baggage that came with the term “UFO” and reframing the discussion as a defense and national security issue. That’s how those of us who have looked at the phenomenon from within government view it.

UFOs have finally come out of the fringe and into the mainstream. Multiple stories have appeared in major media outlets. There is congressional interest. Pilots, radar operators and intelligence officers involved in these encounters and investigations are going on the record, calling for action. It’s difficult to avoid the conclusion that there’s a bigger picture here. The pace of events is picking up, and we seem to be building up to something. Something is happening. Something new. Something big.

Nick Pope worked for the UK Ministry of Defence for 21 years. From 1991 to 1994, he was posted to a division where his duties included researching and investigating unidentified aerial phenomena.