A U.S. congressional hearing is part of a push to convince the government to be more transparent about what it knows about unidentified anomalous phenomena, previously known as UFOs. Watch The National live on YouTube starting at 9 p.m. ET Subscribe to The National: ...

The term UFO has become a catch-all for any unidentifiable aerial phenomenon. Floating lights in the sky, strange readings on aircraft radars, and supposed sightings of little green men on the side of the road. How long have humans been seeing things in the sky? You'll learn about the time the ...