A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

WASHINGTON (Reuters) -Just as Earth orbits the sun, most planets discovered beyond our solar system orbit a host star.

Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our ...

While Planet Y has been not yet been directly observed, unexpected inclinations found in the orbits of roughly 50 distant ...

Astronomers have discovered new evidence that suggests the possibility of an unknown planet in our solar system's farthest ...

A mysterious space object named 2023 KQ14, nicknamed “Ammonite,” challenges theories about the mysterious and possible Planet ...

Space scientists look back on 30 years of exoplanet discoveries — from rows of massive ‘super-Earths‘ to worlds with ...

From lava worlds to gas giants, NASA says the variety of these worlds is staggering—and that signs of a further 8,000 distant ...

On October 6 1995, at a scientific meeting in Florence, Italy, two Swiss astronomers made an announcement that would transform our understanding of the universe beyond our solar system. Michel Mayor ...

Mercury is tiny, barely bigger than the Moon. Its metallic core makes up 70% of the planet’s mass, vastly exceeding Earth’s ...

Orbs with twin suns, a star twice as old as our sun... see how new discoveries, with surprising similarities to fiction, are rewriting our understanding of the universe.