Biggest comet from outer solar system ever seen is 137 kilometres wide

Astronomers have calculated the size of a ‘mega comet’ originating in the Oort Cloud, a cluster of icy bodies that surrounds our solar system

By Jonathan O’Callaghan

Astronomers have confirmed that a “mega comet” flying towards the sun is the biggest comet from the outer solar system ever found.

In June 2021, astronomers announced the discovery of comet C/2014 UN271 (Bernardinelli-Bernstein) beyond the orbit of Uranus. Its brightness suggested it was a vast object originating from a cloud of icy bodies that surrounds our solar system, the Oort Cloud. It was estimated to be between 100 and 370 kilometres across, making it …