The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Here’s what you should know when you go outside to see for yourself: Yes, the planets are indeed lined up across our sky. No, ...

Temperamental' stars that brighten and dim over a matter of hours or days may be distorting our view of thousands of distant planets, suggests a new study.

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course.

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of our Solar System. The planet sizes tested were 1 percent of Earth's mass, ...

While the planets won’t be perfectly aligned, their placement will follow the orbital plane of our solar system. Which planets are parading in January and February? The January planetary ...

"Temperamental" stars that brighten and dim over a matter of hours or days may be distorting our view of thousands of distant ...

WASP-121b is like nothing in the solar system, raining liquid metal and being puffy like a marshmallow. The origins of these ...

Sean Murray says new engine advances in Light No Fire's development creates "…this urge to share it with the [No Man's Sky] ...

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

Mercury joins the night sky to complete a seven-planet alignment just after sunset for the end of February. Saturn leaves our ...