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

A new study claims it is possible an "alien visitor" could have warped our solar system during its earliest years.

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

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

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

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

Images captured by NASA's Solar Dynamics Observatory have revealed that "coronal loops" give off subtle flashes of ...

Tonight and throughout January, stargazers can see a planetary alignment in the night sky or what some are calling a ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But ...

Although it's being mistakenly promoted as a "rare planetary alignment," one of the best "planet parades" in half a century is now taking place. Here's how to see it.