Nanodiamonds Are Not Forever

An anonymous reader writes "Livermore Labs and the Belgian Institute of Astrophysics (Catholic University, Leuven) are reporting today that nanodiamonds trapped by U2 spyplanes are pretty common (one part per 1000 in meteors), but don't originate from violent supernovae as previously thought. Instead their absence in comets suggest they formed after our solar system (are not pre-solar) by chemical vapor deposition -- and from much less violent asteroid collisions. Their technique of spectroscopy is compared to looking for the proverbial needle in a haystack by burning down the haystack. It seems these diamond time capsules are close to perfect tracers for guessing the initial conditions when life first formed in the universe. On April 23-24, a large flux of identifiable comet dust will streak through our stratosphere from the Grigg-Skjellerup earth-crossing dust trail."

Comments

Carbon and CVD

[reverseengineer]

The conclusions in this article make a lot of sense actually- the conditions in the solar system are in many ways similar to a chemical vapor deposition setup- very low pressure, almost no oxygen, and yet still plenty of material to use as both a vapor (carbon) and substrate (asteroids, comets, dust motes, etc.). I'd expect that these nanodiamonds are simply the result of carbon atoms coming together and clustering on a surface, with the carbon of course in conditions suitable for diamond formation. I would expect that nanoscale clusters of the other carbon allotropes, graphite and fullerenes, should be found in abundance in the asteroid belt as well.