"We found what are now the largest molecules known to exist in space," said astronomer Jan Cami of the University of Western Ontario.

"We are particularly excited because they have unique properties that make them important players for all sorts of physical and chemical processes going on in space."

Buckyballs are molecules made from 60 carbon atoms arranged in a three-dimensional sphere.

Their alternating patterns of hexagons and pentagons are similar to the geodesic domes popularised by Buckminster Fuller -- hench buckyballs, more formally known as buckminsterfullerene.

The Cami team unexpectedly found the carbon balls while observing a planetary nebula named Tc 1.

The buckyballs were found in the clouds surrounding the white dwarf star at the heart of the nebule -- perhaps reflecting a short stage in the star's life, when it sloughs off a burst of material rich in carbon.

"We did not plan for this discovery," Cami said.

"But when we saw these whopping spectral signatures, we knew immediately that we were looking at one of the most sought-after molecules."

Sir Harry Kroto, Nobel prize winning co-discoverer of buckyballs, said: "This most exciting breakthrough provides convincing evidence that the buckyball has, as I long suspected, existed since time immemorial in the dark recesses of our galaxy."