New research proves fullerene can be cosmic carbon carriers

Contact: Cheryl Ernst
ernst@hawaii.edu
808 956-5941

UH scientist shows fullerene can be cosmic carbon carriers

A University of Hawai’i geochemist and her colleagues have found extraterrestrial noble gasses
encapsulated within “buckyballs” and other fullerene carbon molecules. The discovery provides a new
tool for tracing extraterrestrial events in Earth’s geological and biological record.
It also lends support to the theory that, throughout time, atmospheric gasses and organic compounds
were delivered to the surface of planets via asteroid and comet strikes, such as the large impact
event that wiped out the dinosaurs 65 million years ago.

“This finding opens new possibilities in looking at the problem of how planetary atmospheres evolved
and maybe even how life evolved on Earth and perhaps other moons and planets” says Luann Becker, a
researcher in the Hawai’i Institute of Geophysics and Planetology in the University of Hawai’i at
Manoa’s School of Ocean and Earth Science and Technology, and first author on the paper.

Discovery of these trapped gasses in fullerenes was made by Becker and Robert Poreda, of the
University of Rochester’s Department of Earth and Environmental Sciences, with Theodore Bunch of NASA
Ames Research Center’s Astrobiology and Space Research Division. Their findings will appear in the
March 28 issue of the Proceedings of the National Academy of Sciences. An advance copy of the article
is available online at www.pnas.org after 5 p.m. EST March 20.

Says Poreda: “We have been working on this for five years. By answering questions that were raised in
response to our earlier findings, this paper clearly confirms what we said in 1995” about fullerenes
as potential delivery systems for extraterrestrial gasses.

Work published by Becker and Bunch in Nature last July, first identified naturally occurring
fullerenes in a meteorite. Fullerenes are molecules of 60 or more carbon atoms formed into a hollow
cage-like structure. They are named for Buckminster Fuller because the 60-atom C60 structures called
“buckyballs” resemble the designer’s geodesic dome. The scientists had found significant quantities of
very large fullerene molecules, containing as many as 400 carbon atoms, in samples from the
4.6-billion-year-old Allende meteorite that landed in Mexico three decades ago.

The subsequent work examined several Cretaceous/Tertiary boundary (KTB) sediments distributed
worldwide, including deposits in Denmark, New Zealand and North America. In each case, fullerenes
encapsulated noble gasses with unmistakably extraterrestrial and possibly extra-solar signatures.
“Helium from different sources on Earth, like our atmosphere or the emissions from volcanoes, have a
very different signature from the helium in a meteorite,” Becker explains. “The helium we found within
the fullerene cages of Australia’s Murchison meteorite, for example, is similar to the helium that
existed when our solar system first formed.” That finding points to a cosmic source for the
fullerenes, since molecules formed in the pressure of an earthly impact event or the heat of wildfires
that followed would have encapsulated terrestrial helium.

The scientists looked at the KTB because it is a well-studied sediment layer already shown to contain
extraterrestrial iridium, which is a platinum group element, and highly shocked minerals. This
sediment layer marks a period of abrupt change in Earth’s biology and geology, characterized by mass
extinction of the dinosaurs, now generally attributed to the impact of a carbonaceous asteroid that
collided with Earth.

Becker hopes to expand the research to other periods of mass extinction–such as the even more
devastating event that delineated the Permian/Triassic boundary 250 million years ago. She hopes to
determine if extraterrestrial events trigger global change, including whether fullerenes were the
original care packages that delivered volatiles along with the carbon necessary to establish life on
Earth.

“We now have a powerful new tracer to look at the sediment layer very carefully,” she says.
Becker also hopes to work with astronomers to study the formation of fullerenes. “We have yet to learn
why these things are there and what they tell us about carbon forming in the universe. We need to
figure out how to establish their existence and how to search for it.”

The research was supported by grants from the NASA Cosmochemistry and Exobiology Program.

CONTACTS:
Luann Becker, University of Hawaiåi, 808 956-5010, lbecker@soest.hawaii.edu
Robert Poreda, University of Rochester, 716 275-0051
Theodore Bunch, NASA Ames Research Center Space Science Division, 520 717-1916

NOTE:
Lead author Luann Becker will be available in Houston Friday/Saturday March 17-18, for telephone
interviews. To make arrangements, contact Cheryl Ernst, 808 956-5941, ernst@hawaii.edu.
Dr. Becker will return to Hawaiåi March 20.

28 March 2000: Fullerenes: An extraterrestrial carbon carrier phase for noble gases, Proceedings of the National Academy of Sciences (abstract)