Buckyballs detected in space

Soccer ball-shaped carbon molecules first discovered on Earth in the 1980s have been detected in outer space.

Fullerenes, also known as buckminsterfullerenes or "buckyballs," were detected about 6,500 light years from Earth in the cosmic dust of Tc 1, an object known as a planetary nebula, researchers reported in a study published online Thursdayin Science Express.

Scientists had long speculated that buckyballs, made up of 60 carbon atoms joined in a cage-like sphere, existed in space and might be responsible for light being mysteriously absorbed in space, said Jan Cami, an astronomer at the University of Western Ontario in Londonwho was the lead author of the study.

"Now that we know for sure that these fullerenes do actually exist in space we can actually turn the question around and say 'How big could their influence be in terms of these absorptions?' So that's a much more specific question."

A planetary nebula such as Tc 1 is the last stage in the life of a star and is generally a colourful object with a small star called a white dwarf at its centre, Cami said.

"It's surrounded by these layers of gases that glow typically in red and green. Those gases are actually what used to be the outer layer of the star."

Researchers trained the Spitzer Space Telescope on Tc 1, which is visible at high magnification in the constellation Ara from the Earth's Southern Hemisphere. They measured the infrared light absorbed by molecules in its dust cloud, which are unique for each type of molecule and can serve as a chemical fingerprint to identify them.

Jeronimo Bernard-Salas, a researcher at Cornell University in Ithaca, N.Y., and atUniversit Paris-Sud in Orsay, France, who specializes in studying the dust of planetary nebulae, noticed that the spectrum of Tc 1 was unusual. The dust didn't contain carbon chains or rings that are normally found near planetary nebulae.

Bernard-Salas sent the spectrum to other researchers, including Cami, who recognized the signature as almost a perfect match for the fullerenes known as C60 and C70 (named for the number of carbon atoms in each).

On Earth, buckyballs are produced in the lab by heating up graphite, the carbon material found in pencil leads, in the absence of hydrogen gas, with a little bit of helium.

Unusual environment

The researchers found that Tc 1 had an unusual environment that didn't have much hydrogen near it either.

"And it's apparently exactly those conditions that you need to be able to efficiently produce buckyballs," Cami said.

That doesn't mean the researchers think buckyballs in space are rare.

"From our understanding this might actually be a phase that a lot of planetary nebulae go through," Cami said. But he suggested there are two reasons why researchers had never detected buckyballs around planetary nebulae before.

First of all, the stage at which fullerenes can be detectedis likely short, at least on an astronomical scale.

From their measurements, the researchers found that the buckyballs they detected wereclose toroom temperature.That meant theywere at a distancefrom the star indicating they wereejected about 100 years ago.

In another 100 years, theywould be so cold they would be undetectable, Cami said: "There's some luck involved you need to happen to catch the object in the right stage."

Secondly, researchers only recently built an instrument for the space telescope sensitive enough to measure something so far away.