This marine chronometer was given to President Ronald Reagan by singer Frank Sinatra. The quest for the Longitude Prize spurred a wave of innovation and ingenuity in the scientific community.

For centuries, determining longitude was an extremely difficult task for sailors, so difficult that it's been thought improbable -- if not impossible -- for animals to do it. But migratory sea turtles ...

Some 250 years ago, a British astronomer published the first of a series of guidebooks that would ultimately establish Greenwich, England, as the world's zero-degree longitude location, the "prime ...