In June 1937, celebrated aviator Amelia Earhart set out to become the first woman to fly around the world, a trip of 29,000 miles (46,671 kilometers). She'd completed all but the final 7,000 miles (11,265 kilometers) by July 2, when she and her navigator Fred Noonan took off from Lae in Papua, New Guinea, for a 2,556-mile (4,114-kilometer) flight to Howland Island, a small island in the Pacific.
A U.S. Coast Guard cutter, the Itasca, was stationed just off shore, and two other ships were positioned along the flight route as markers for Earhart's plane. Nevertheless, the plane ran into overcast skies and intermittent rain showers that made celestial navigation, Noonan's favorite method, difficult. The next morning at 7:42, the Itasca picked up this radio transmission from Earhart: "We must be on you, but we cannot see you. Fuel is running low." About an hour later, Earhart radioed, "We are running north and south" [source: AmeliaEarhart.com].
That was her last transmission, and her plane never arrived. Rescuers mounted, what was at the time, the most massive search in aviation history, searching 250,000 square miles (647,497 square kilometers) of ocean in a fruitless attempt to find her. Some believe the plane crashed in the ocean and the passengers were killed; others, that they survived the crash but died of thirst on a remote island, or else that they were taken alive as hostages by the Japanese who though they were spies [source: Roach and Than]. To this day, Earhart and Noonan's fate remains a mystery.