The outer solar system contains some chunks of ice and rock that orbit so far from the sun that it’s hard to imagine how they got there, but an ancient rogue planet may hold the key.
October 1, 2022
A rogue planet twice the size of Earth may have pushed asteroids into the far reaches of the early solar system before it was ejected. This could solve the mystery of how some of the most distant Kuiper belt objects got there, something that most models of solar system formation cannot explain.
The Kuiper Belt is a huge disk of cold rock and ice that extends beyond the orbit of Neptune. …