Answers are grounded in this paper and cite their sources.
First experimental investigations of spherical three-dimensional plasma crystals consisting of hundreds or thousands of micrometer-sized polymer particles suspended in a radio-frequency gas discharge are described. These "Coulomb balls" are not subject to the formation of dust-free regions (voids) and have an unusual structure of nested crystalline shells. While small systems are in a solid phase, large systems show melting effects.
No takes yet. Share an insight, caveat, or question.
Arp et al. (2004) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: