A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

The simulation of the Solar System that came the closest to the observation was the presence of a small planet, between the ...

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

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

For almost a decade, astronomers have been searching for a ninth planet in the solar system. Recently, new evidence of ...

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

A low-density, puffy planet orbiting relatively far from a young star in a nearly perpendicular orbit. What's going on?

The James Webb Telescope captures the beginning of planetary formation around the young star HOPS-315 for the first time.

Astronomers are investigating a strange class of exoplanets known as eccentric warm Jupiters — massive gas giants that orbit their stars in unexpected, elongated paths. Unlike their close-orbiting ...

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

The methane gas may constitute a rarefied atmosphere, or it may come from erupting plumes on Makemake’s surface.

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 ...