As the comet disintegrates on its journey around the Sun, some of the pieces that have broken off are as big as a house.
Before the comet began to fall apart, NASA estimates it was comparable in length to one or two football fields.
Quanzhi Ye, of the University of Maryland, College Park, part of the second Hubble observing team, said: “This is really exciting – both because such events are super cool to watch and because they do not happen very often.
“Most comets that fragment are too dim to see.
“Events at such scale happen only once or twice a decade.”