Astronomer Eliza Kempton said that she had waited her "entire career" to peer into an atmosphere from this mysterious class of planets.

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

Macduff met the Herald this week at the Jupiter basalt marker along the Columbia Park Trail, just east of the blue bridge. It ...

Earth has four seasons, but do other planets in our solar system also have hot summer days and cold winter nights?

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...

At a frigid -125 degrees Fahrenheit (-87 degrees Celsius), WD 1856+534 b is the coldest planet ever directly observed, ...

The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. In 1983 ...

Caroline Delbert is a writer, avid reader, and contributing editor at Pop Mech. She's also an enthusiast of just about ...

The presence of another planet in the solar system could explain the odd movements of some of the bodies in the Kuiper Belt.

Astronomers have detected a promising sign of a ninth planet lurking at the the farthest reaches of the Solar System.