When the solar system began assembling its first solid bodies—planets, moons, and protoplanets—it had two possible raw ingredients: heat-forged chondrules, which are millimeter-sized bits of rock, and matrix, a fine-grained cold dust. According to a report from Phys.org, the early solar system effectively chose fire over ice, relying more heavily on the heat-processed chondrules than on the cold dust matrix.
The study behind the report highlights that chondrules were the dominant building blocks for the first solid bodies. Matrix, while present, played a secondary role. This distinction matters because it changes how researchers understand the thermal history of the early solar system—suggesting that high-temperature processes were more central to planetesimal formation than previously appreciated.
No contradicting sources were available, so the account stands alone. The finding does not rule out ice or cold dust entirely, but it does shift the emphasis toward heat-forged materials as the primary starting point for solid bodies.