There are a few strategies for keeping nuclear weapons from accidentally detonating, including where and how the nuclear components are stored.
Canadian Prime Minister Justin Trudeau said the U.S. shot down an unidentified flying object over the Yukon, Canada at his request.
A ring looping around the icy dwarf planet Quaoar is located much farther from its parent body than scientists thought was possible.
A woman's strange case of "foreign accent syndrome" left doctors unsure of its cause.