Asteroids are rocky objects that orbit the Sun, just like planets do. There are millions of asteroids of very different shapes and sizes. Some are almost spheres, like planets, but most are ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

This size and proximity to its star classifies TOI ... Yet this newly found planet isn't a hot Jupiter. With a width around two times that of our planet and a mass eight times that of Earth ...

Ever since NASA's New Horizons sent back the first-ever photos of Pluto in 2015, the dwarf planet's mysterious heart ... roughly the size of Arizona from north to south. Pluto was discovered ...