Qicheng Zhang at all.
https://iopscience.iop.org/article/10.3847/PSJ/acc866
Our analysis shows that Phaethon's comet-like activity cannot be explained by any kind of dust," said Qicheng Zhang, a California Institute of Technology PhD student who led the new study into Phaethon, in a NASA statement(opens in new tab).
see: Expanding Earth, by Growing Water based Crashed Comet core.
Interference Black Holes, Photonic Molecules, Ball Lightning, Micro Comets, Sprite-Fireballs and Sunspots According to Quantum FFF Theory.
Comet and Ball Lightning micro black holes compressed by the local dark energy axion vacuum and repelling all Fermions,