Usually the government sticks to reality, but there are a number of times where agencies have investigated or weighed in on more mythical ideas.
From mermaids to Santa Claus, here are 11 legends that the government has acknowledged, even if just to deny.
Click here to see the myths >
More From Mental_Floss:
Wondering where Santa Claus is every Christmas? The North American Aerospace defence Command (NORAD) holds the answer with their annual Santa Tracker, which provides up-to-the-minute updates on where Father Christmas is delivering presents. The tradition started in 1955, when Sears posted an ad in a Colorado Springs newspaper with a number for children to call Santa. However, a misprint led to children actually calling a local Continental Air defence Command (CONAD) centre, a military precursor to NORAD. The on-duty colonel told everyone at the base to give any children who called a location for Santa. Today the location is given out through a Google Earth map on the NORAD Santa Tracker website.
Verdict: He's right there!
The FBI's online vault contains a treasure trove of documents for UFO enthusiasts, detailing various investigations and general interest into unexplained objects. The UFO page contains many reports of events between 1947 and 1954, including some that touch on the Roswell crash. Their verdict? Just a weather balloon.
Verdict: Not real, but worth investigating.
Pretty much every alien invasion movie scenario was covered in a 2011 paper written by a NASA scientist along with colleagues from Penn State, including the possibility that aliens could attack humans because we're wasteful. The report considered a number of scenarios for alien contacts, everything from them coming in peace to their desire for destruction. Many of them fell on the slightly boring side -- they could come and be unable to communicate with humans, or they could accidentally carry a deadly disease. To make sure things will be OK, the researchers say that the best course of action is to not broadcast out our biological information and stick to communicating on a mathematical level until any alien intentions become clear.
Verdict: It's possible
Business Insider Emails & Alerts
Site highlights each day to your inbox.