A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches.

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

To better understand Jupiter’s primordial stages, researchers turned to the tiniest of the planet’s 92 known moons. Almathea ...

Planets with unusually wide orbits may be normal by-products of the formation of planetary systems. This is suggested by new simulations.

Our solar system may ... the outskirts of the solar system is the activity within the Kuiper Belt, an unusual clustering of icy bodies -- including comets and dwarf planets -- which stretches ...