Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

An artist's concept depicting the pulsar planet system. (Photo by: Universal History Archive/Universal Images Group via Getty Images) Rarely even acknowledged as the first planets discovered beyond ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

Astrophysicists at the University of Warwick have found an unusual ring of metal-rich gas orbiting very close around a white dwarf star. The presence of the ring helps solve a problem for astronomers ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

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. When ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...