Back in 2013, on Valentine’s Day, the Internet was fascinated with videos of a fireball entering the atmosphere over Chelyabinsk, Russia. The meteor appeared out of nowhere, approaching from the Sun side during the day, previously unseen by astronomers. And when the meteor hit the atmosphere, it caused a sonic boom and shock wave that fragmented the approximately 20-meter rock and shattered windows throughout the town.
And there were massive amounts of footage of the event from many different angles thanks to the saturation of dashboard cameras in the region. Which turned out to be incredibly helpful for the scientists who wanted to hunt down the fragments.
Now, in a new paper published in The European Physical Journal Plus, scientists have published results on an analysis of the dust that coats those meteorites. This dust forms on the surface when the meteor is exposed to high temperatures and pressures upon entry into the atmosphere. And since these particular fragments landed in snow and ice, that dust ended up preserved on the surface.
Using scanning electron microscopy, the researchers found some unusual crystals – closed, quasi-spherical shells and hexagonal rods. And they turned out to be made of carbon formed when graphene layers built up on carbon nuclei. The team theorizes that these molecules could be buckminsterfullerenes – Buckyballs – made of 60 carbon atoms.
And with another new paper published in The Astrophysical Journal with lead author Hassan Sabbah, another meteorite has actually revealed the presence of Buckyballs in a meteorite for the first time. That meteorite is called Almahata Sitta, and it was discovered in 2008 by a team of scientists and volunteers tracking the fragments based on radar data – also a first in the field of meteorites.
This particular set of meteorites originated from a previously unknown asteroid now cataloged as 2008 TC3, and many of the pieces turned out to be ureilites. Ureilites are rather exotic in the meteorite world as they are bits of the mantle of partially melted, carbon-rich asteroids. That means they are fairly primitive pieces of our early solar system.
And using a mass spectrometer called Astrochemistry Research of Organics with Molecular Analyzer or AROMA, the team made what is being called the “first unambiguous detection in a meteorite of buckminsterfullerenes and other fullerenes.” To confirm the unique discovery, scientists also performed the same analysis on two other primitive meteorites and found no evidence of fullerenes.
Despite the theory about the Chelyabinsk meteor and its potential fullerenes, the team, in this case, disputes the re-entry origin theory, as co-author Cyrena Goodrich notes: Although this was a high-temperature event, it was still not hot enough to have created fullerenes from pre-existing carbon phases.
So it could be that this asteroid had an interstellar origin, somewhere close to a massive star in the molecular cloud of formation. But we’ll need more data and evidence to prove that origin story, a task that could be performed by JWST in the coming years.
More Information
Exotic carbon microcrystals in meteorite dust (EurekAlert)
SETI Institute press release
“Exotic carbon microcrystals in meteoritic dust of the Chelyabinsk superbolide: experimental investigations and theoretical scenarios of their formation,” Sergey Taskaev et al., 2022 May 7, The European Physical Journal Plus
“Detection of Cosmic Fullerenes in the Almahata Sitta Meteorite: Are They an Interstellar Heritage?“, Hassan Sabbah et al., 2022 May 27, The Astrophysical Journal
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