The Oort cloud

shell of icy bodies · source of long-period comets

2,000 to 100,000 AU from the Sun

Trillions of comet nuclei surround the Sun out to a light-year or more, a third of the way to the nearest star. None has ever been seen directly.

• outer edge ~100,000 AU (1.6 light-years)
• a comet from here takes millions of years per orbit

Numbers that change with time are from 8 November 2026.

kind

place in the Solar System