Largest known comet is heading close enough to us to become visible By Ashley Strickland, CNN enablePagination: false endIndex: (CNN) — Astronomers have discovered the largest known comet, and it's about a thousand times more massive than others. Comet Bernardinelli-Bernstein, so named because it was found by University of Pennsylvania department of physics and astronomy graduate student Pedro Bernardinelli and Professor Gary Bernstein, is between 62 to 124 miles (100 to 200 kilometers) across. The team announced the discovery in June. This unusual comet will make its closest approach to our sun in 2031, but you'll likely need a large amateur telescope to see it. The giant comet, also known as C/2014 UN271, is from the outskirts of our solar system and has been making its way toward our sun for millions of years. This is also the most distant comet to be discovered on its inbound journey, which will provide scientists a chance to observe and study it for years to come.