The Oort cloud, sometimes known as the "Öpik-Oort cloud", is a theoretical spherical cloud of icy objects surrounding the Sun that lie beyond the Kuiper belt. The Oort cloud is thought to extend from between 2,000 and 5,000 AU (0.03 - 0.08 light years) to as far as 50,000 AU (0.79 light years) from the Sun. Some estimates place the outer edge as far as 100,000 to 200,000 AU (1.58 and 3.16 light years).
The Oort cloud is thought to be compromised of two regions - a spherical outer Oort cloud of 20,000 - 50,000 AU (0.32 - 0.79 light years) and a disc-shaped inner Oort cloud of 2,000 - 20,000 AU (0.03 - 0.32 light years).