The blob, captured on distant, fuzzy video by Navy pilots, seems to skitter just above the ocean waves at improbable speed, with no discernible means of propulsion or lift. “Oh my gosh, man,” one aviator says to another as they laugh at the oddity. “What ... is it?”

Is it a bird? A plane?

Super drone? An extraterrestrial something? The US government has been taking a hard look at unidentified flying objects like this one. A report summarising what the US knows about “unidentified aerial phenomena”—better known as UFOs—is expected to be made public this month.