Comet Swift–Tuttle, parent of the 2026 Perseids, has an approximate orbital period of 133 years.
The comet follows a long, elongated orbit around the Sun and returns to the inner Solar System roughly once every thirteen decades. Its quoted period is an approximation because gravitational interactions, especially with Jupiter, alter the exact timing from one return to another.
Swift–Tuttle is classified as a Halley-type comet because its orbital period is between 20 and 200 years. Its repeated passages shed dust that remains distributed along the comet’s orbit, forming the Perseid meteoroid stream encountered by Earth each year.
The 133-year period should not be confused with the interval between Perseid showers. The meteor shower is annual because Earth crosses the stream every year, whereas the comet itself takes more than a century to complete one orbit. Its most recent perihelion was in 1992, and its next is expected in 2126.