Imagine a massive celestial bubble made of ice and dust surrounding our Solar System. That’s the Oort cloud and this is its scale.

The Oort Cloud lies at the very edges of the Solar system. Even the farthest ones which are still working, like Voyager 1, Voyager 2 and New Horizons didn't go beyond the cloud.

Long-period comets, taking centuries to orbit the Sun, provide evidence for the existence of the Oort Cloud. Scientists believe this vast region is the birthplace of these cosmic travelers.⁠