Did asteroids flock together to build planets?

 作者:臧赋     |      日期:2019-03-14 07:18:02
By David Shiga PERHAPS we should thank rapid-assembly asteroids for spawning the planets. New simulations suggest that dense swarms of boulders collapsed under their own gravity to make the building blocks of our solar system. The planets are thought to have formed from a disc of dust and gas around the infant sun. The initial process is well known: dust grains clumped together, forming objects in the millimetre-to-metre range. However, it is not known how the growth process continued. The gas in the disc should have put a drag on the new boulders,