There's new interest in one of the past century's most alluring mysteries and a grainy sonar image is at the heart of both excitement and skepticism.

A leather helmet that Amelia Earhart wore on a flight across the Atlantic in 1928 and later lost in a crowd of fans in Cleveland sold at auction for $825,000.

FILE - In this Nov. 6, 2014, file photo Supreme Court Justice Antonin Scalia speaks in Washington. The president unveiled his plan Friday, July 3, 2020, during his speech at Mount Rushmore National Memorial, S.D. We will raise the next generation of American patriots, Trump said at Mount Rushmore. None will have lived perfect lives, but all will be worth honoring, remembering, and studying, according to the order. The order includes language to make clear that non-U.S. citizens who played significant roles in American history also could be honored in the garden.

Bob Ballard and Allison Fundis speak onstage during the TCA panel for National Geographic Channels' Bob Ballard's Next Great Discovery at The Beverly Hilton Hotel on July 23, 2019, in Beverly Hills, California. (CNN) - Deep-sea explorer Bob Ballard, who in 1985 made headlines for his discovery of the remains of the Titanic, has announced plans to solve another of history's greatest mysteries: What happened to missing-in-action aviation pioneer Amelia Earhart. Setting sail on Aug. 7, National Geographic explorer-at-large Ballard and National Geographic Society archeologist-in-residence Fredrik Hiebert will lead a team of Earhart experts, scientists and technicians on a month-long journey that will take them from Samoa to a remote Pacific atoll called Nikumaroro in the Republic of Kiribati. This project is jointly funded by National Geographic Partners and National Geographic Society. It will be part of a two-hour special titled "Expedition Amelia" that will premiere Oct. 20 on National Geographic.

Library of Congress via CNNATCHISON, Kan. - Amelia Earhart was a trailblazing pilot and an OG girl-power icon who broke gender stereotypes along with aviation records. So on Amelia Earhart Day, which honors her birth on July 24, 1897, here's a look at the pioneering aviator's brief life and fascinating legacy. She almost had a medical careerDuring the first World War, Earhart worked as a Red Cross nurse's aide in Canada. In 1929 she joined other women aviators in forming The Ninety-Nines, an organization for female pilots. Then there's the theory ignited by the 1970 book "Amelia Earhart Lives," by Joe Klaas, who argues the aviator never actually died in 1937 but served as a spy during World War II.