Could a passing star be on a collision course with our solar system and, eventually, Earth? It’s difficult to know if such an outcome is likely. Recently, researchers have found the Milky Way likely ...

The formation of Mercury remains an unsolved mystery. The planet closest to the sun has a disproportionately large metallic core—accounting for about 70% of its mass—and a relatively small rocky ...

Scientists have shown that Earth’s basic chemistry solidified within just three million years of the Solar System’s formation. Initially, the planet was barren and inhospitable, missing water and ...