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 ...

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

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

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

Starting up again Saturday, a sweeping view of our solar system will glow in the night sky. The planetary alignment, or a ...

A shortcut for New Yorkers to spot some of the planets is to look for them when they are near the moon. On Feb. 1, Venus will ...

"This planet could play a pivotal role in future missions... to search for biosignatures indicating potential life, " Dr.

When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

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