Heavy Asteroid Polyhymnia Could Be Hiding electric charged micro back holes (Q-FFF Theory) like starspots or ball lightning like comet 67P CG, creating CH4 / CH2 and Silicon.
Below at the top of the bill ? or heavier?: "High-density asteroid Polyhymnia may be composed of elements greater than the heaviest one in the periodic table, synthesised oganesson with atomic number 118 (bottom right of the main table with chemical designation Og). Image via Wikimedia Commons (CC BY-SA 4.0)"
The incident dusty explosion seems to be triggered by the negative electric charge tension between the Ball Lightning and the earth.