The disappearance of Malaysia Airlines Flight 370 has left experts perplexed, leading to a variety of unsubstantiated theories about what might have happened. Unfortunately, if history is any judge, it’s possible we may never know. Here are five other examples of missing flights that vanished without a trace, and remain unsolved to this day. Amelia Earhart Perhaps the most famous missing pilot in history, Amelia Earhart vanished over the central Pacific Ocean near Howland Island in 1937 during an attempt to become the first female to circumnavigate the globe by flight. Though some clues have emerged over the years, and theories abound, Earhart’s plane has yet to be found. A recent discovery off the coast of Nikumaroro island, an uninhabited tropical atoll in the southwestern Pacific, offers new hope that the Earhart mystery may soon have a resolution. A sonar scan has revealed what some experts believe could be Earhart’s crashed Lockheed Electra plane, and an expedition to the island is scheduled in 2014 to look into the findings. Lending credence to the evidence, researchers have previously found what appears to be a jar of ’30s-era freckle cream on Nikumaroro island, along with an American-made woman’s compact, buttons and the zipper from a flight jacket. Could this be Earhart’s final resting place? We’ll have to wait for the expedition to know for sure. See the other 9 at Care2 Healthy Living.