The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

An object eight ... A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new ...

She has covered weird animal behavior, space news and the impacts of climate ... the researchers describe how they modeled the orbits of the four outer planets and performed 50,000 simulations ...