The famous pilot Amelia Earhart vanished in 1937 during an attempt to fly around the world. Her disappearance sparked a massive $4 million search and decades of speculation:

• Did her plane run out of gas?
• Was her navigator drunk?
• Was she spying for President Roosevelt, and then taken captive?

The pursuit of the truth about Amelia Earhart continues today--more than 65 years after her disappearance.

In October 2003 a man claiming to know where Amelia Earhart is buried stepped forward and announced that he knew the location of her grave on Tinian, an island in the west Pacific. (See the news item on her official Web site.) Although this isn't the first time such a claim has been made, historians are investigating.

In August of the same year, a group called The International Group for Historic Aircraft Recovery (TIGHAR) was also in the Pacific looking for (among other things) bones, a sextant, a box, and part of a woman's shoe. These artifacts were first found in 1941 on an island near where Earhart is believed to have gone down, but have since disappeared.

TIGHAR has been investigating the Earhart mystery for more than 15 years. They have uncovered evidence that dispels some of the more prominent theories about her disappearance. They argue, for example, that Earhart couldn't have run out of gas because she had about four hours of fuel in her tank at the time her plane disappeared. They also report that there was no evidence that her navigator Frederick Noonan--one of the best in the world at the time--had a drinking problem.

Nor is there proof she was a spy, or taken prisoner. Hollywood stoked the public's imagination, though, with a film released in 1943 called "Flight for Freedom," which speculated that Earhart was a spy. Although such rumors are saucy, most of them are merely spicy concoctions without much meat. Investigations by army intelligence and the media came up short on evidence.

After years of research, TIGHAR has concluded that Earhart and her navigator survived their crash and lived for awhile, marooned on a desert island. The pair likely died from infection, food poisoning, thirst, or other possible causes. TIGHAR's final report is published online, along with an intriguing run-down of possible culprits in the disappearance of the evidence.

So why does the mystery persist?

Perhaps because Earhart was such a remarkable person. Our curiosity about her disappearance might really be inspired by our fascination with what made her who she was: a woman before her time. Even today, only about six percent of commercial pilots are women.

So beyond the well-known questions regarding her disappearance, perhaps the more fascinating mystery is what drove Amelia Earhart to seek the ends of the Earth.