The sun, planets and Voyager probes sit inside the tiny yellow dot at right, within a giant sphere called the Oort cloud. This reservoir of trillions of ice chunks extends astronomical units out, tethered to the sun by gravity.
This Is A Map Of The Entire Universe, Squeezed Into One Mind-Boggling Image
What is the Oort Cloud? The Oort Cloud is an extended shell of icy objects that exist in the outermost reaches of the solar system. It is named after astronomer Jan Oort, who first theorized its existence. The Oort Cloud is roughly spherical.
long-period comets come from Oort cloud; their orbits suggest that the cloud is a spherical shell close to a light-year across, bisected by a doughnut; the rest of the solar system lies in the doughnut hole