撞击塑造了地球最早的陆壳

Impacts shaped Earth’s first continents Heat from large impacts may have melted most of Earth’s earliest crust Qian Yuan The early Solar System (about 4.6 billion years ago) evolved through massive collisions of Mars-sized planetary bodies whose orbits occasionally crossed (1, 2). After this early period, large impacts remained common until around 3.9 billion years ago (3). For Earth, the decrease in strikes broadly coincided with the emergence of continental crust (4). However, it has been unclear why continental crust did not develop earlier in Earth’s history (5, 6). On page 1408 of this issue, Johnson et al. …