Earth's magnetic field creates a protective bubble known as the magnetosphere, which surrounds the planet and shields us from solar wind—a rush of charged particles, or plasma, constantly streaming from the sun. (Related: "'Warm Plasma Cloak' Discovered Enveloping Earth.")

As the solar wind pushes on Earth's magnetic bubble, the planet's magnetosphere stretches, forming what's called the magnetotail. This tail reaches beyond the orbit of the moon, and it's always pointed away from the sun. (See NASA illustrations of how the moon and the magnetotail interact.)

Meanwhile, we see a full moon when the lunar orb is on the opposite side of Earth from the sun—and therefore within the magnetotail.

A strong electric field near