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

When you first learned about the Solar System, you probably saw diagrams that made it look orderly, with planets arranged in ...

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of ...

For much of January and February, you have the chance to see six planets in our solar system after dark, although two — Uranus and Neptune — will be hard to see without a telescope or high-powered ...

23: Autumn is here The autumnal equinox is one of two points in Earth’s orbit where the sun creates equal periods of daytime and nighttime across the globe. Many mark it as the first day of the ...