Search for Buried Treasure With This DIY Magnetometer

In the 1968 movie 2001: A Space Odyssey, an oddness in the moon’s magnetic field leads scientists to an alien monolith buried under Tycho crater. The notion of being led to a hidden object by virtue of the magnetic anomaly it creates must have really intrigued my 9-year-old self, because a decade after seeing that movie I decided to build a circuit to measure the strength of Earth’s magnetic field. So I read some World War II–era journal articles and learned about the magnetometers used to locate submerged German submarines. With that information, I constructed what’s called a fluxgate magnetometer. It was crude, but it worked.