New Study Shows Largest Comet Ever Observed Was Active at Near-Record Distance

Artist's rendition of the Bernardinelli-Bernstein (BB) comet.

Comet Bernardinelli-Bernstein (BB), represented in this artist rendition as it might look in the outer Solar System, is estimated to be about 1000 times more massive than a typical comet. The largest comet discovered in modern times, it is among the most distant comets to be discovered with a coma, which means ice within the comet is vaporizing and forming an envelope of dust and vapor around the comet's core. (Image: J. da Silva via NOIRLab / NSF / AURA)