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 ...

For those of us with no real navigation experience, encountering longitude and latitude coordinates is usually the result of some hiccup using Google Maps. 40.722272, -73.994194? What? Where the heck ...

Ever wonder how the Global Positioning System (GPS) works? This extraordinarily complex system is actually based on some simple concepts. Find out what they are in this Shockwave game.

Last month we described how to use the sky to find your latitude, which specifies how far you are north or south of the equator. But latitude is only half the story. You also need to know how far east ...