How big is Buckyball? | Scale of the Universe

A buckyball is a molecule of 60 carbon atoms joined into a closed, ball-shaped cage, with the same pattern as a soccer ball. Its full name is buckminsterfullerene, and its formula is C₆₀. It is about 1 nanometer across, measured as the distance between the centers of neighboring buckyballs packed together in a solid. A nanometer is a billionth of a meter.

Size

The 60 carbon atoms sit on the surface of the cage, which is hollow. Its discoverers later found carbon cages with metal atoms trapped inside. The cage of carbon atoms itself is 0.71 nanometers across.

A molecule has no hard edge, because the electrons around its atoms reach beyond their centers. So each buckyball takes up more room than its cage of atoms. In crystals of solid C₆₀, the centers of neighboring molecules are 1.0 nanometers apart. The explorer's figure of 1 nanometer matches that spacing.

The cage has 20 six-sided faces and 12 five-sided faces. A soccer ball's panels follow the same pattern. So does the geodesic dome that the American architect R. Buckminster Fuller designed for the 1967 world's fair in Montreal, and the molecule is named after him.

Size comparisons

About 80,000–100,000 buckyballs side by side would span a human hair, which is 0.08–0.1 millimeters wide.
A soccer ball is about 220 million times as wide as a buckyball. A soccer ball enlarged by that same factor would be about 48,000 kilometers (30,000 miles) across, nearly four times as wide as Earth.
Two cesium atoms, among the largest atoms, would span a buckyball side by side.

How buckyballs were discovered

Robert Curl, Harold Kroto and Richard Smalley discovered buckyballs in 1985, working with graduate students J. R. Heath and S. C. O'Brien. They fired an intense pulse of laser light at a carbon surface and mixed the freed carbon atoms with a stream of helium gas. The atoms joined into clusters, and clusters of 60 atoms were the most common. Their stability suggested a highly symmetrical shape.

In 1990, the physicists W. Krätschmer and D. R. Huffman made C₆₀ in amounts large enough to collect. Studying it confirmed the ball-shaped structure. Curl, Kroto and Smalley shared the 1996 Nobel Prize in Chemistry for the discovery of fullerenes, the family of closed carbon cages that buckyballs belong to.

Buckyballs in space

Kroto joined the experiment to learn how chain-shaped carbon molecules he had found in the atmospheres of carbon-rich giant stars might form. Soon after the discovery, scientists proposed that buckyballs might float around such stars. In 2010, NASA's Spitzer Space Telescope found convincing signs of them in space for the first time.

Spitzer found buckyballs in Tc 1, a cloud of material shed by a dying star. The star was once like the Sun, but as it aged it shed its outer layers. Astronomers think the buckyballs formed in the shed layers of carbon.