Every so often, there's a comet that's so bright it can light up the night sky. But a couple times a year, comets that have long since passed by, or maybe even disintegrated entirely, can light up the night sky, too.
The phenomenon is called the Zodiacal Light and it's the result of a giant cloud of comet dust that stretches from Mercury to Jupiter. It's about as bright as the Milky Way and it's visible with the naked eye about two hours before sunrise in the fall; two hours after sunset in the spring.
