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

Astronomers have made a groundbreaking discovery in the WASP-132 system, finding two new planets that defy previous ...

"A parade of planets, also sometimes referred to as a planetary alignment, is when several planets in our solar system appear ...

This may explain the strange properties of the orbits of our solar system's planets, which are not quite perfectly circular, and all lie on slightly different planes. NASA artist’s conception of ...

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests. The ...