Some locations on Earth confound experts with phenomena and events that science cannot explain. Discover Eternal Flame Falls, the Plain of Jars, Cave of Crystals, Stone Spheres, and Fairy Circles.

An astronaut on the International Space Station captured mysterious blue spheres in the sky last year. NASA’s Earth Observatory shared the photo last year, as well, shortly after it was taken.

Cavendish was able to measure the force between two metal spheres separated by a known distance. The gravitational force of the Earth exerted on the smaller ball could be measured by weighing it ...