Scientists have discovered evidence that indicates the planets in our solar system formed suddenly in collapses of dense dust rather than slow, incremental buildups of rock via asteroid collisions, per New Scientist.
The reasoning: Researchers tracked 17 asteroids over 4 billion years old in the inner asteroid belt, finding that their sizes range from 35 to 100 kilometers across. If planets had formed incrementally, ancient asteroids would have had to be much smaller in size, lending more credence to the theory that planetary formation was sudden and catastrophic.
Why it matters: These findings lead scientists to believe that there's a serious chance that planets form through the same massive dust collapses everywhere in the universe.