---
title: "Oort Cloud: facts, distance and size – Krillion Space"
description: "The Oort Cloud is a vast shell of icy bodies thought to surround the solar system far beyond Pluto and the Kuiper Belt. Size, distance and sourced facts."
url: https://krilion.app/atlas/oort-cloud
language: en-US
---

# Oort Cloud

Comet reservoir. Depth 16 on the Krillion Space voyage, in the Outer Sol.

The Oort Cloud is a vast shell of icy bodies thought to surround the solar system far beyond Pluto and the Kuiper Belt. It has never been directly observed; astronomers infer it mainly from long-period comets that fall inward from every direction.

![The Oort Cloud at depth 16 in Krillion Space, painted by the game (an illustration, not a photograph).](https://krilion.app/assets/atlas/oort-cloud.webp)

## Fact sheet

- **Type:** Theoretical comet reservoir
- **Distance:** Thought to begin about 2,000 to 5,000 AU from the Sun
- **Size:** Thought to reach out to about 10,000 to 100,000 AU, a thick shell around the whole Solar System
- **Discovered:** Proposed 1950 by Jan Oort (never directly observed)
- **On the voyage:** Depth 16, in the Outer Sol section of the route, between Voyager 1 and Alpha Centauri

## Things to know

- Astronomer Jan Oort proposed the cloud in 1950 to explain where long-period comets come from and why they arrive from all directions. ([NASA](https://science.nasa.gov/solar-system/oort-cloud/facts/))
- It may hold hundreds of billions, possibly trillions, of icy objects. ([NASA](https://science.nasa.gov/solar-system/oort-cloud/facts/))
- NASA has no direct images of the Oort Cloud because it is so far away. ([NASA](https://science.nasa.gov/solar-system/oort-cloud/))
- Sunlight would need up to about a year and a half to reach the cloud's outer edge. ([NASA](https://science.nasa.gov/solar-system/oort-cloud/facts/))
- Voyager 1 is not expected to enter the Oort Cloud for about 300 years and could take about 30,000 years to pass beyond it. ([NASA](https://science.nasa.gov/solar-system/oort-cloud/facts/))

## Sources

- [NASA – Oort Cloud Facts](https://science.nasa.gov/solar-system/oort-cloud/facts/)
- [NASA – Oort Cloud](https://science.nasa.gov/solar-system/oort-cloud/)

## On the route

- Previous landmark: [Voyager 1](https://krilion.app/atlas/voyager-1)
- Next landmark: [Alpha Centauri](https://krilion.app/atlas/alpha-centauri)
- [The whole Star Atlas](https://krilion.app/atlas)
- [Fly the voyage yourself](https://krilion.app/d/): every right answer warps your ship one stop deeper.