The Kuiper belt is a vast ring of icy objects orbiting the Sun beyond Neptune, one of the outer planets in our solar system. Imagine a giant donut of frozen rocks and ice chunks, stretching out into the darkness of space, starting about 3 billion miles from the Sun and extending billions of miles farther.

The Kuiper belt contains millions of these frozen worlds, most no bigger than a house or a small town, though some are hundreds of miles across. Pluto, once considered our ninth planet, is actually one of the larger objects in the Kuiper belt. These icy chunks are leftovers from when our solar system formed over 4 billion years ago, like construction scraps left behind after building a house.

Scientists believe many comets come from the Kuiper belt. When something bumps one of these icy objects, it might fall toward the inner solar system, where the Sun's heat turns its ice into gas and dust, creating the spectacular glowing tail we can see from Earth.

Exploring the Kuiper belt helps us understand what the early solar system was like, frozen in time at the edge of our cosmic neighborhood.