A meteor hit the earth and exploded with 2.1 kilotonnes of force last month, but the US Air Force has made no mention of the event.
NASA's Jet Propulsion Laboratory confirmed an object of unspecified size travelling at 24.4 kilometres per second struck earth in Greenland, just 43 kilometres north of an early missile warning Thule Air Base on the 25th of July, 2018.
Director of the Nuclear Information Project for the Federation of American Scientists, Hans Kristensen, tweeted about the impact, but America's Air Force has not reported the event.
Mr Kristensen argues it's concerning there was no public warning from the US government about the incident.