Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.

For the first time since 2008, two new planets are being added to one of northern Maine's most famous — and scientifically accurate — roadside attractions. Dwarf planets Haumea and Makemake are the ...

A newly studied solar system breaks the usual planet pattern, raising fresh questions about how rocky and gas planets form.

A small red dwarf star in the Milky Way has drawn attention after astronomers mapped four closely orbiting planets around it. The system, known as LHS.

A scale model of the solar system, with each planet depicted in relief on individual square granite markers installed atop concrete bases embedded in the ground. Each planet bears a laser etched ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

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 ...