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

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...

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

Astronomers have discovered extremely powerful winds pummeling the equator of WASP-127b, a giant exoplanet. Reaching speeds ...

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

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 ...

Beyond Neptune lies the Kuiper Belt, a vast expanse of icy bodies that may hold clues to the solar system’s formation. These ...

Baker said that there are other astronomical events that may be more interesting than the parade of planets. Baker said Mars ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

Six of our cosmic neighbors are expected to line up across the night sky tonight, in what has been dubbed a "planetary parade ...