A periodic comet is a type of comet that has a predictable orbit around the Sun, allowing it to return to the inner solar system at regular intervals. These comets typically have orbits that last from a few years to several decades. The most famous example is Halley's Comet, which returns approximately every 76 years. Periodic comets are composed of ice, dust, and rocky material. As they approach the Sun, the heat causes the ice to vaporize, creating a glowing coma and often a tail that points away from the Sun. This process makes them visible from Earth, providing a spectacular display in the night sky.