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 small red dwarf star in the Milky Way has drawn attention after astronomers mapped four closely orbiting planets around it.

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 ...

Astronomers have revealed new research showing that millions of new solar system objects are likely to be detected by a brand-new facility, which is expected to come online later this year.

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 ...